RESULTS CHAPTER IV. 4. A. Occurrence of blue green algae

Transcription

1 CHAPTER IV RESULTS 4. A. Occurrence of blue green algae Blue green algae are common in all kinds of natural habitats. Many species are cosmopolitan, distributed throughout the world. Water logged rice fields is one of the major habitats for growth of a wide variety of blue green algae. They constitute one of the vital components of rice field soil micro flora and have significant importance in rice field ecosystem. In the present study, a survey was made on the blue green algae growing in the rice fields of Dhubri for four years 2006 to It was observed that they are common in both winter and summer rice fields in the district. Certain blue green algae were found as permanent and often dominant components of the phytoplankton in the water of rice fields forming water blooms. The paddy field ecosystem provides a favorable environment for the growth of blue green algae with respect to their requirements for light, water, high temperature and also nutrient availability. This may account for the higher abundance of blue green algae in paddy field soils than in other cultivated soils (Watanabe and Yamamoto, 1970) under widely different climatic conditions of India. In the paddy fields, the relative abundance of blue green algae varies within large limits. 4. A. 1. Blue green algae in rice field It was observed that rice fields of Dhubri district are very rich in blue green algal flora. During the present investigation a total of 157 species belonging to 38 genera in 12 families were identified from the rice fields. Out of these 52 species were from heterocystous and 105 were non-heterocystous blue green algae. In the non-heterocystous group 56 free-living or colonial unicellular species were recorded in the rice fields during the study. Different families, genera and species of blue green algae encountered during the studies are listed

2 Results 38 below (list-1) along with their respective orders as follows (Microscopic photograph plate No.1-22 and Camera lucida drawing plate no. I-V). List-1: Blue green algae species in different families. Class- CYANOPHYCEAE Order- CHROOCOCCALES Family- Chroococcaceae Genus- Microcystis 1. Microcystis aeruginosa Kütz. 2. Microcystis bengalensis Banerji. 3. Microcystis flos-aquae (Wittr.) Kirchner. 4. Microcystis pulverea var. incerta (Lemm.) Crow. Genus- Chroococcus 5. Chroococcus cohaerens (Bréb) Näg. 6. Chroococcus dispersus Lemm. 7. Chroococcus indicus Zeller. 8. Chroococcus macrococcus (Kütz.) Rabenh. 9. Chroococcus minimus var. crassa Rao, C.B. 10. Chroococcus minor (Kütz.) Näg. 11. Chroococcus minutus (Kütz.) Näg. 12. Chroococcus montanus forma Rao, C.B. 13. Chroococcus montanus var. hyalinus Rao, C.B. 14. Chroococcus pallidus Näg. 15. Chroococcus schizodermaticus West. 16. Chroococcus tenax (Kirchn.) Hieron. 17. Chroococcus turgidus (Kütz.) Näg. Genus- Gloeocapsa 18. Gloeocapsa atrata (Turp) Kütz. 19. Gloeocapsa calcarea Tilden 20. Gloeocapsa compacta Kütz.

3 Results Gloeocapsa crepidinum Thuret 22. Gloeocapsa decorticans (A.Br.) Richter 23. Gloeocapsa magma (Bréb) Kütz. 24. Gloeocapsa montana Kütz. 25. Gloeocapsa nigrescens Näg 26. Gloeocapsa pleurocapsoides Novacek. 27. Gloeocapsa polydermatica Kütz. 28. Gloeocapsa quaternata (Bréb) Kütz. 29. Gloeocapsa sanguinea (Ag.) Kütz. 30. Gloeocapsa stegophila var. crassa Rao. Genus- Gloeothece 31. Gloeothece fuscolutea Näg. 32. Gloeothece membranacea (Rabenh.) Bornet. 33. Gloeothece rupestris (Lyngb) Bornet. 34. Gloeothece rhodochlamys Skuja. 35. Gloeothece samoensis var. major Wille. Genus- Aphanocapsa 36. Aphanocapsa banaresensis Bharadwaja. 37. Aphanocapsa biformis A.Br. 38. Aphanocapsa grevillei (Hass) Rabenh. 39. Aphanocapsa koordersi Strom. 40. Aphanocapsa muscicola Wille. 41. Aphanocapsa pulchra (Kütz.) Rabenh.

4 Results 40 Genus- Aphanothece 42. Aphanothece microscopica Näg. 43. Aphanothece pallida (Kütz.) Rabenh. 44. Aphanothece stagnina (Spreng.) A. Braun. Genus- Synechococcus 45. Synechococcus aeruginosus Näg. Genus- Synechocystis 46. Synechocystis aquatilis Sauv. 47. Synechocystis pevalekii Ercegovic. Genus- Gomphosphaeria 48. Gomphosphaeria aponina Kütz. Genus- Merismopedia 49. Merismopedia punctata Meyen. 50. Merismopedia tenuissima Lemm. Genus- Dactylococcopsis 51. Dactylococcopsis raphidioides Hansg. Family: Entophysalidaceae Genus- Chlorogloea 52. Chlorogloea fritschii Mitra. Order-CHAMAESIPHONALES Family: Chamaesiphonaceae Genus Chamaesiphon 53. Chamaesiphon rostaffinskii (Rostaf.) Hansgirg.

5 Results 41 Family: Dermocarpaceae Genus- Dermocarpa 54. Dermocarpa leibleiniae (Reinsch) Bore et Thur. Genus- Stichosiphon 55. Stichosiphon sansibaricus (Hieron) Drouet & Daily. Order-PLEUROCAPSALES Family: Pleurocapsaceae Genus- Myxosarcina 56. Myxosarcina burmensis Skuja. Order-NOSTOCALES Family: Oscillatoriaceae Genus- Arthrospira 57. Arthrospira spirulinoides Ghose. Genus- Spirulina 58. Spirulina gigantea Schmidle. 59. Spirulina major Kütz. ex Gomont. 60. Spirulina meneghiniana Zanard. ex Gomont. 61. Spirulina princeps West. Genus- Oscillatoria 62. Oscillatoria acuta Bruhl et Biswas. 63. Oscillatoria anguina (Bory) Gomont. 64. Oscillatoria annae van Goor. 65. Oscillatoria chalybea var. insularis Gardner. 66. Oscillatoria chilkensis Biswas.

6 Results Oscillatoria chlorina Kütz. ex Gomont. 68. Oscillatoria curviceps Ag. ex Gomont. 69. Oscillatoria formosa Bory ex Gomont 70. Oscillatoria limosa Ag. ex Gomont. 71. Oscillatoria nigroviridis Thwaites. 72. Oscillatoria okeni Ag. ex Gomont. 73. Oscillatoria perornata Skuja. 74. Oscillatoria princeps Vaucher ex Gomont. 75. Oscillatoria princeps var. pseudolimosa Ghose. 76. Oscillatoria proteus Skuja. 77. Oscillatoria raoi De Toni J. 78. Oscillatoria rubescens Dc ex Gomont. 79. Oscillatoria salina Biswas. 80. Oscillatoria subbrevis Schmidle. 81. Oscillatoria tenuis Ag. ex Gomont. 82. Oscillatoria vizagapatensis Rao C.B. Genus- Phormidium 83. Phormidium ambiguum Gomont. 84. Phormidium ceylanicum Wille. 85. Phormidium corium (Ag.) ex Gomont. 86. Phormidium fragile (Meneghini) Gomont. 87. Phormidium lucidum Kütz. ex Gomont. 88. Phormidium retzii (Ag.) ex Gomont. 89. Phormidium tenue (Menegh) Gomont. 90. Phormidium valderianum (Delp) Gomont.

7 Results 43 Genus- Lyngbya 91. Lyngbya aestuarii Liebm. ex Gomont. 92. Lyngbya arboricola Bruhl et Biswas. 93. Lyngbya contorta Lemm. 94. Lyngbya limnetica Lemmermann. 95. Lyngbya lutea (Ag.) ex Gomont. 96. Lyngbya major Menegh ex Gomont. 97. Lyngbya majuscula Harvey ex Gomont. 98. Lyngbya mesotricha Skuja. 99. Lyngbya polysiphoniae Frémy Lyngbya porphyrosiphonis Frémy Lyngbya truncicola Ghose. Genus- Symploca 102. Symploca cartilaginea (Mont) Gomont Symploca hydnoides Kützing ex Gomont Symploca muscorum (Ag.) ex Gomont. Genus- Hydrocoleum 105. Hydrocoleum cantharidosum (Mont.) Gomont. Family: Nostocaceae Genus- Cylindrospermum 106. Cylindrospermum indicum Rao. Genus- Nostoc 107. Nostoc calcicola Brébisson Nostoc ellipsosporum (Desm.) Rabenh.

8 Results Nostoc linckia (Roth) Bornet Nostoc muscorum Ag. ex Gomont Nostoc paludosum Kützing Nostoc punctiforme (Kütz) Hariot Nostoc spongiaeforme Agardh. Genus- Anabaena 114. Anabaena ambigua Rao, C.B Anabaena anomala Fritsch Anabaena azollae Strasburg Anabaena doliolum Bharadwaja Anabaena fertilissima Rao, C.B Anabaena gelatinicola Ghose Anabaena iyengarii var. tenuis Rao, C.B Anabaena oryzae Fritsch Anabaena sphaerica Bornet et Flah Anabaena variabilis Var. ellipsospora Fritsch. Genus- Raphidiopsis 124. Raphidiopsis indica Singh, R.N. Genus- Aulosira 125. Aulosira fertilissima Ghose Aulosira fritschii Bharadwaja. Family: Scytonemataceae Genus- Camptylonemopsis 127. Camptylonemopsis iyengarii Desikachary.

9 Results 45 Genus- Scytonema 128. Scytonema burmanicum Skuja Scytonema crustaceum Ag. ex Born et Flah Scytonema hofmanni Ag. ex Born et Flah Scytonema guyanense (Mont) Born et Flah Scytonema multiramosum Gardner Scytonema malaviyaensis Bharadwaja Scytonema schmidtii Gom. Genus- Tolypothrix 135. Tolypothrix byssoidea (Berk) Kirchner Tolypothrix tenuis (Kütz) Johs. Family: Microchaetaceae Genus- Microchaete 137. Microchaete uberrima Carter. N. Family: Rivulariaceae Genus- Homoeothrix 138. Homoeothrix hansgirgi (Schmidle) Lemm. Genus- Calothrix 139. Calothrix brevissima var. moniliforme Ghose Calothrix castellii Massal. Born Calothrix fusca Kütz Bornet Calothrix marchica Lemmermann Calothrix scytonemicola Tilden Calothrix stellaris Bornet & Flah.

10 Results 46 Genus- Rivularia 145. Rivularia beccariana (De Not) Born et Flah Rivularia hansgirgi Schmidle Rivularia manginii Frémy. Genus- Gloeotrichia 148. Gloeotrichia intermedia var. kanwaensis Rao Gloeotrichia longicauda Schmidle Gloeotrichia natans Rabenhorst Gloeotrichia pilgeri Schmidle Gloeotrichia raciborskii Woloszynska Gloeotrichia kashiense Rao, C.B. Family: Mastigocladaceae Genus- Mastigocladus 154. Mastigocladus laminosus Cohn. Order-STIGONEMATALES Family: Stigonemataceae Genus- Stigonema 155. Stigonema dendroideum Frémy Stigonema lavardei Frémy Stigonema turfaceum Cooke ex Born.

11 Results 47 Figure 1 : Blue green algal species % in different orders

12 Sl. No Results 48 Table-1: Occurrence and distribution of blue green algae in the rice fields in three study sites : Site-II Site-I (Agomoni Site-III (Jarua (Bilasipara rice rice field ) rice field) field) Name of Species Family: Chroococcaceae Win Pm Mn Rm 1 Microcystis aeruginosa Microcystis bengalensis Microcystis flos-aquae Microcystis pulverea var. incerta Win Pm Mn Rm Win Pm Mn Rm Total Relative Abundance % Chroococcus cohaerens Chroococcus dispersus Chroococcus indicus Chroococcus macrococcus 9 Chroococcus minimus var. crassa Chroococcus minor Chroococcus minutus Chroococcus montanus forma 13 Chroococcus montanus var. hyalinus Chroococcus pallidus Chroococcus schizodermaticus Chroococcus turgidus Chroococcus tenax Gloeocapsa atrata Gloeocapsa calcarea Gloeocapsa compacta Gloeocapsa crepidinum Gloeocapsa decorticans Gloeocapsa magma Gloeocapsa montana Gloeocapsa nigrescens Gloeocapsa pleurocapsoides Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

13 Results 49 Sl. No Name of Species Site-I (Agomoni rice field ) Win Pm Mn Rm Site-II (Bilasipara rice field) Win Pm Mn Rm Site-III (Jarua rice field) Win Pm Mn Rm Total Relative Abundance % 27 Gloeocapsa polydermatica Gloeocapsa quaternata Gloeocapsa sanguinea Gloeocapsa stegophila var. crassa Gloeothece fuscolutea Gloeothece membranacea Gloeothece rupestris Gloeothece rhodochlamys 35 Gloeothece samoensis var. major 36 Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa grevillei Aphanocapsa koordersi Aphanocapsa muscicola Aphanocapsa pulchra Aphanothece microscopica Aphanothece pallida Aphanothece stagnina Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

14 Results 50 Sl. No Name of Species Site-I (Agomoni rice field ) Win Pm Mn Rm Site-II (Bilasipara rice field) Win Pm Mn Rm Site-III (Jarua rice field) Win Pm Mn Rm Total Relative Abundance % 45 Synechococcus aeruginosus Synechocystis aquatilis Synechocystis pevalekii Gomphosphaeria aponina Merismopedia punctata Merismopedia tenuissima 51 Dactylococcopsis raphidioides Family: Entophysalidaceae 52 Chlorogloea fritschii Family: Pleurocapsaceae 53 Myxosarcina burmensis Family: Chamaesiphonaceae 54 Chamaesiphon rostaffinskii Family: Dermocarpaceae 55 Dermocarpa leibleiniae Stichosiphon sansibaricus Family: Oscillatoriaceae 57 Arthrospira spirulinoides Spirulina gigantea Spirulina major Spirulina meneghiniana Spirulina princeps Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

15 Results 51 Sl. No Name of Species Site-I (Agomoni rice field ) Win Pm Mn Rm Site-II (Bilasipara rice field) Win Pm Mn Rm Site-III (Jarua rice field) Win Pm Mn Rm Total Relative Abundance % 62 Oscillatoria acuta Oscillatoria anguina Oscillatoria annae Oscillatoria chalybea var. insularis Oscillatoria chilkensis Oscillatoria chlorina Oscillatoria curviceps Oscillatoria formosa Oscillatoria limosa Oscillatoria nigroviridis Oscillatoria okeni Oscillatoria perornata Oscillatoria princeps Oscillatoria princeps var. pseudolimosa Oscillatoria proteus Oscillatoria raoi Oscillatoria rubescens Oscillatoria salina Oscillatoria subbrevis Oscillatoria tenuis Oscillatoria vizagapatensis Phormidium ambiguum Phormidium ceylanicum Phormidium corium Phormidium fragile Phormidium lucidum Phormidium retzii Phormidium tenue Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

16 Results 52 Sl. No Name of Species Site-I (Agomoni rice field ) Win Pm Mn Rm Site-II (Bilasipara rice field) Win Pm Mn Rm Site-III (Jarua rice field) Win Pm Mn Rm Total Relative Abundance % 90 Phormidium valderianum Lyngbya aestuarii Lyngbya arboricola Lyngbya contorta Lyngbya limnetica Lyngbya lutea Lyngbya major Lyngbya majuscula Lyngbya mesotricha Lyngbya polysiphoniae Lyngbya porphyrosiphonis Lyngbya truncicola Symploca cartilaginea Symploca hydnoides Symploca muscorum Hydrocoleum cantharidosum Family: Nostocaceae 106 Cylindrospermum indicum Nostoc calcicola Nostoc ellipsosporum Nostoc linckia Nostoc muscorum Nostoc paludosum Nostoc punctiforme Nostoc spongiaeforme Anabaena ambigua Anabaena anomala Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

17 Results 53 Sl. No Name of Species Site-I (Agomoni rice field ) Win Pm Mn Rm Site-II (Bilasipara rice field) Win Pm Mn Rm Site-III (Jarua rice field) Win Pm Mn Rm Total Relative Abundance % 116 Anabaena azollae Anabaena doliolum Anabaena fertilissima Anabaena gelatinicola Anabaena iyengarii var. tenuis Anabaena oryzae Anabaena sphaerica Anabaena variabilis var. ellipsospora Raphidiopsis indica Aulosira fertilissima Aulosira fritschii Family: Scytonemataceae 127 Camptylonemopsis iyengarii Scytonema burmanicum Scytonema crustaceum Scytonema hofmanni Scytonema guyanense Scytonema multiramosum Scytonema malaviyaensis Scytonema schmidtii Tolypothrix byssoidea Tolypothrix tenuis Family: Microchaetaceae 137 Microchaete uberrima Family: Rivulariaceae 138 Homoeothrix hansgirgi Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

18 Results 54 Sl. No Name of Species Site-I (Agomoni rice field ) Win Pm Mn Rm Site-II (Bilasipara rice field) Win Pm Mn Rm Site-III (Jarua rice field) Win Pm Mn Rm Total Relative Abundance % 139 Calothrix brevissima var. moniliforme Calothrix castellii Calothrix fusca Calothrix marchica Calothrix scytonemicola Calothrix stellaris Rivularia beccariana Rivularia hansgirgi Rivularia manginii Gloeotrichia intermedia var. kanwaensis Gloeotrichia longicauda Gloeotrichia natans Gloeotrichia pilgeri Gloeotrichia raciborskii Gloeotrichia kashiense Family: Mastigocladaceae 154 Mastigocladus laminosus Family: Stigonemataceae 155 Stigonema dendroideum Stigonema lavardei Stigonema turfaceum Total Win=winter, Pm=pre-monsoon, Mn=monsoon, Rm=retreating monsoon

19 Results 55 4.A.2. Distribution of blue green algae The different the species of blue green algae are not uniformly distributed in the rice fields of Dhubri district. It was observed that 157 species of blue green algae distributed in 38 genera and 12 families under 5 orders of the class Cyanphyceae. The distribution of species among the different families were found as in the following arrangement in the order Chroococcocales there are 12 genera and 52 species in two families namely Chroococcaceae and Entophysalidaceae. In the family Chroococcacae there observed 11 genera with 51 species, and Entophysalidaceae had 1 genus with 1 species during the investigation. These 51 unicellular species were distributed among the following genera as Microcystis aeruginosa, Microcystis bengalensis, Microcystis flosaquae and Microcystis pulverea var. incerta. The genus Chroococcus was represented with 13 species namely Chroococcus cohaerens, Chroococcus dispersus, Chroococcus indicus, Chroococcus macrococcus, Chroococcus minimus var. crassa, Chroococcus minor, Chroococcus minutus, Chroococcus montanus forma, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Chroococcus schizodermaticus, Chroococcus turgidus and Chroococcus tenax. The genus Gloeocapsa was with 13 species such as Gloeocapsa atrata, Gloeocapsa calcarea, Gloeocapsa compacta, Gloeocapsa crepidinum, Gloeocapsa dcorticans, Gloeocapsa magma, Gloeocapsa montana, Gloeocapsa nigrescens, Gloeocapsa pleurocapsoides, Gloeocapsa polydermatica, Gloeocapsa quaternata, Gloeocapsa sanguinea, and Gloeocapsa stegophila,. In Gloeothece there were 5 species Gloeothece fuscolutea, Gloeothece membranacea, Gloeothece rupestris, Gloeothece rhodochlamys and Gloeothece samoensis. In the genus Aphanocapsa there were 6 species, they were Aphanocapsa banaresensis, Aphanocapsa biformis, Aphanocapsa grevillei, Aphanocapsa koordersi, Aphanocapsa muscicola and Aphanocapsa pulchra. In Aphanothece there were 3 species namely Aphanothece microscopica, Aphanothece pallida and Aphanothece stagnina. There were some genera with single species such as Synechococcus aeruginosus, Gomphosphaeria aponina and Dactylococcopsis raphidiodes were found the family Chroococcaceae. The genus

20 Results 56 Synechocystis represented by only 2 species Synechocystis aquqtilis and Synechocystis pevalekii and Merismopedia was with 2 species Merismopedia punctata and Merismopedia tenuissima. In family Entophysalidaceae only one species Chlorogloea fritschii was observed in the area. Thus in Chroococcales a total of 52 species were distributed in the sudy area. In Chamaesiphonales there are two families observed Chamaesiphonaceae and Dermocarpaceae. Chamaesiphonceae represented by a single species Chamaesiphon rostaffinskii and Dermocarpaceae was with two species Dermcarpa leibleiniae and Stichosiphon sansibaricus. Chamaesiphonales was found with two genera and 3 species. In the order Pleurocapsales there is one genus and one species Myxosarcina burmensis. Nostocales was found as the dominating order with 6 families 21 genera with 98 species of blue green algae in the study area. Oscillatoriaceae was observed as the most abundantly distributed family in the district representing 7 genera and 49 species, the genera are Arthrospira, Spirulina, Oscillatoria, Phormidium, Lyngbya, Symploca and Hydrocoleum. The family Nostocaceae observed with 5 genera and 21 species as Cylindrospermum, Nostoc, Anabaena, Raphidiopsis and Aulosira in the area. The family Scytonemataceae was represented by 3 genera with 10 species such as Camptylonemopsis, Scytonema and Tolypothrix. Microchaetaceae was represented by Microchaete uberrima. Again, family Rivulariaceae was represented by 16 species included in 4 genera Homoeothrix, Calothrix, Rivularia and Gloeotrichia. On the other hand Mastigocladus laminosus was found as the single species in Mastigocladaceae. The family Stigonemataceae was represented by 3 species such as Stigonema dendroideum, Stigonema lavardei and Stigonema turfaceum. (List- 1) The distribution pattern of the different species was studied with the help of relative abundance of species, their diversity index, and similarity coefficient and species richness in all three study sites and in four seasons. A total of 237 soil and water samples were collected during the investigation. It observed that the members of Oscillatoriaceae were dominantly distributed in the area which were distributed in 211 samples ( %) followed by Chroococcaceae ( %),

21 Results 57 Nostocaceae (35.021%), Rivulariaceae (19.409%), Scytonemataceae (13.924%), Dermocarpaceae (3.375%), Stigonemataceae (2.109 %) and each of Entophysalidaceae, Chamaesiphonaceae, Microchaetaceae and Mastigocladaceae was distributed with (0.844 %) and the lowest being the family Pleurocapsaceae (only 0.42 %) were the pattern of distribution of blue green algae in the district (Table -1, Fig. 3). Fig 3: Distribution of species in different families of blue green algae Fig 4: Diversity of thallus in blue green algae

22 Results 58 It observed that the blue green algae are widely distributed in the rice fields of the district. The relative abundance percentage of each encountered species in the district was calculated and observed as Oscillatoria acuta, Oscillatoria limosa and Oscillatoria perornata (each with 4.64 % relative abundance) were the most dominant members occurring in highest number of species in the collected samples followed by Phormidium corium(4.21%), Chroococcus pallidus, Oscillatoria annae, Phormidium ambiguum, Nostoc spongiaeforme and Nostoc ellipsosporum (3.37% each), and that of Gloeocapsa quaternata, Chroococcus minimus, Merismopedia punctata, Cylindrospermum indicum and Anabaena sphaerica (2.95 %), Lyngbya limnetica and Scytonema crustaceum (2.53 % each) and some unicellular members like Chroococcus montanus, Gloeocapsa pleurocapsoides, Gloeocapsa sanguinea etc., umicellular colonial forms such as Myxosarcina burmensis, filamentous forms as Spirulina meneghiniana, Symploca muscorum, Anabaena doliolum, heterocystous members like Rivularia beccariana, Gloeotrichia natans and Stigonema turfaceum are distributed with least relative abundance of only 0.42 % in the study area. Again, among the different locations, the rice fields located in Agomoni observed highest number of blue green algae isolates with 202 species samples in all seasons against 180 in Bilasipara and 201 in Jarua rice fields, South Salmara. So it revealed that Site-I is found most suitable location for harboring blue green algae in the district. (Fig.-5). Site-I: Agomoni rice fields, Site-II: Bilasipara rice fields, Site-III: Jarua rice fields Fig. 5: Distribution of algae in three study Sites

23 Results 59 Table 2: Distribution percentage of algae in seasons and sites Blue green algae distribution percentage in seasons Rice fields Winter Premonsoon Monsoon Retreating monsoon Site-I (Agomoni) Site-II (Bilasipara) Site-III (Jarua) Fig. 6: Distribution & Seasonal variation % of algae 4.A.2. Seasonal variation of species Seasonal variation of the algae of the district was studied during the study period The blue green algal populations were found highly susceptible and exhibit rapid variations in their quality and quantity in different seasons of the year. The appearance of some blue green algae observed in rice fields few days after the first rain in the early monsoon. During monsoon season (May to August), in the rice cultivation period number of algae fall. This may be due to disturbances in their habitats during field preparation for cropping. Again, after seedling transplantation completed, the growth of algae was more. During winter 62, 56 and 53 blue green algae species was encountered in site-i,

24 Results 60 (Agomoni rice fields), site-ii, (Bilasipara rice fields) and in site-iii, (Jarua rice fields, South salmara) respectively; while in pre-monsoon season 41 species each in site-i and site-ii and 45 in site-iii was recorded. Least number of species was observed in the monsoon season in all three sites with 31, 21 and 28 species in site-i, Site-II and Site-III respectively. The highest number of species was found to occur during retreating monsoon (September to November) with 68 species in site-i, 62 in site-ii and 75 in site-iii distributed in the district. Some of the species like Anabaena sphaerica, Gloeocapsa polydermatica, Lyngbya major, Nostoc muscorum, Oscillatoria subbrevis, were found to occur in all the seasons of the year. (Table 3, Fig. 7) Table 3: Seasonal variation of algae in study sites No. of algal species Seasons Site-I (Agomoni) Site-II (Bilasipara) Site-III (Jarua) Winter Premonsoon Monsoon Retreating monsoon Fig. 7: Seasonal variation and distribution of algae in study sites

25 Results 61 4.A.3. Diversity Index of species To understand and quantify the blue green algal community structure of the study area, rarity or commonness in distribution of the blue green algal species in the three study sites of the district in respect four different seasons, the diversity index of algal species was calculated by Shannon-Weaver (1964). Diversity Indices indicate that during retreating monsoon season highest number of different blue green algal species were found to appear in all the three study sites. Among the different seasons and sites Agomoni rice fields (i.e. Site-I) of Dhubri was found as the richest location for highest blue green algal diversity with species richness 54 during retrating monsoon and the highest diversity index of species observed among all seasons and sites. On the other hand the lowest diversity index of species among all seasons and sites was observed in Bilasipara rice fields (Site-II) during monsoon season with species richness 17 indicates minimum algal diversity in the rice fields in the season in the area. In Jarua rice fields the highest diversity index of species observed during retreating monsoon season with 54 different species whereas in this location (Site-III) the lowest diversity index of species was observed during monsoon season with species richness of 22. It was observed that more blue green algae were encountered during retreating monsoon season in all 3 sites of the study area. Where as Bilasipara rice fields have the lowest diversity index of in monsoon, indicating comparatively poor in blue green algal diversity during monsoon with the distribution of 17 blue green algal species in that season. (Table-4, Fig. 8) It was observed that Agomoni rice fields were rich in diverse types of blue green algal forms in the retreating monsoon, with 68 species with species richness 54, than any other location of the district against any seasons and the individuals in the community are distributed more equitably among these species. In Site-III though the highest 75 number of algae species distributed less equitably with diversity index (3.8772) and species richness of 55 in the retreating monsoon season.

26 Results 62 Table 4: Diversity Index of species in Seasons and Locations Sites Seasons Diversity Index Total Species (Shannonspecies richness Weaver) Remarks Winter Pre-monsoon Site-III Site-II Site-I Monsoon Lowest diversity Retreating Highest diversity Monsoon Winter Pre-monsoon Monsoon Lowest diversity Retreating Highest diversity Monsoon Winter Pre-monsoon Monsoon Lowest diversity Retreating Highest diversity Monsoon Site-I: Agomoni rice field, Site-II: Bilasipara rice field, Site-III: Jarua rice field Fig. 8: Diversity Index of species in seasons and locations

27 Results 63 4.A.4. Similarity coefficient of species The similarity among different species in different seasons and locations of the study sites was calculated following Sorensen s co-efficient of similarity (1948). It is seen that a highest of 19 common species was found in both Jarua rice field (site-iii) during pre monsoon season and Agomoni rice field (site-i) during the retreating monsoon season with the highest Sorensen s similarity coefficient The 19 similar species that were observed as common Agomoni rice field during retreating monsoon and Jarua rice fields in premonsoon season are Chroococcus pallidus, Gloeocapsa quaternata, Merismopedia punctata, Dactylococcopsis raphidioides, Chamaesiphon rostaffinskii, Oscillatoria acuta, Oscillatoria annae Oscillatoria chilkensis, Oscillatoria perornata, Oscillatoria limosa, Phormidium ceylanicum, Phormidium lucidum, Nostoc ellipsosporum, Anabaena fertilissima, Anabaena sphaerica, Camptylonemopsis iyengarii, Scytonema malaviyaensis, Tolypothrix tenuis and Calothrix castellii. Similarly the lowest similarity co-efficient of species with only one Aphanothece pallida species was observed in Agomoni rice field between pre-monsoon and monsoon season isolates. Higher values of similarity co-efficient of species indicate the occurrence of more common species in locations during the particular seasons (Tables-1, 5, Fig.-9). Table 5: Similarity Co-efficient of species among different seasons and locations (Sorensen s similarity co-efficient, 1948) Site-I:Agomoni field Site-II:Bilasipara field Site-III:Jarua field Seasons Wn Pm Mn Rm Wn Pm Mn Rm Wn Pm Mn Rm to Site-I : Agomoni field Site-II Bilasipara field Wn Pm Mn Rm Wn Pm Mn Rm Wn Site-III : Jarua field Pm Mn Rm Seasons: Wn= Winter, Pm= Pre Monsoon, Mn= Monsoon, Rm = Retreating Monsoon

28 Results 64 It observed that similarity co-efficient of species (highest) indicate the occurrence of 19 (highest) common species in Agomoni and Jarua rice fields during retreating monsoon and pre monsoon seasons respectively in the study area. Seasons: Wn= winter, Pm= Pre monsoon, Mn= Monsoon, Rm = Retreating monsoon Rice field locations: Site-I: Agomoni, Site-II: Bilasipara, Site-III: Jarua Fig. 9: Similarity Co-efficient of species in different seasons and locations 4.A.5. Statistical analysis Table 6: One-way ANOVA showing the season-wise algal occurrence at different rice field sites A: Number of algae occurring samples in study sites and seasons Rice field sites Winter season Pre-monsoon season Monsoon season Retreating monsoon season Site-I Site-II Site-III Rice field sites : Site-I=Agomoni, Site-II=Bilasipara, Site-III=Jarua

29 Results 65 B: Data summary of ANOVA test Seasons 1.Winter 2.Premonsoon 3.Monsoon 4.Retreating Total monsoon N X Mean X varience Std.Dev Std.Err C: ANOVA Summary Sum of square df Meansquare F P Treatment [between groups] < ** Error Total Indication : * Non-significant, ** Significant One-way ANOVA test reveal that P value is < indicates highly significant. So, there is a significant difference between season-wise occurrences of algae at different study sites in the study area (Table-6). Table 7: Tukey HSD test showing the season-wise algal occurrence at different study sites HSD [.05]= 12.77; HSD [.01]= Winter vs. Pre-monsoon P <.05* Winter vs. Monsoon P<.01** M1 = mean of Winter M2 = mean of PreMonsoon M3=men of monsoon M4= men of retreating monsoon Winter vs. Retreated monsoon P>0.05 Premonsoon vs. Monsoon P<.05* Pre-monsoon vs. Retr. moonsoon P<.01** Monsoon vs. Retreated monsoon P<.01** HSD = the absolute [unsigned] difference between any two sample means required for significance at the designated level. HSD [.05] for the.05 level; HSD[.01] for the.01 level. P>0.05 Nonsignificant, P<0.05 * significant, P<.01 ** highly significant

30 Results 66 Tukey HSD test indicates that there were significant differences of algal occurrence between winter vs pre-monsoon and pre-monsoon vs monsoon seasons; highly significant between winter vs monsoon, pre-monsoon vs retreated-monsoon and monsoon vs retreated monsoon seasons but found nonsignificant between winter vs retreated-monsoon seasons in the study area (Table-7). 4. B.1 Pesticide effect on blue green algae in fields The effect of four selected pesticides namely 2, 4-D, Bavistin, Malathion and Cypermethrin were tested at recommended dose on naturally occurring blue green algae to see their tolarence in field condition. In the study site-1 (Agomoni Belguri) rice fields 78 species of blue green algae observed in the controlled rice fields. It was observed that all blue green algae were not affected equally in 2, 4-D pesticide treatment in fields. The species that could not grow in 2, 4-D treated rice fields were Microcystis flosaquae, Chroococcus cohaerens, Gloeocapsa nigrescens, Gloeocapsa polydermatica, Gloeocapsa stegophila, Gloeothece samoensis and Aphanocapsa biformis among the unicellular blue green algae. While among the filamentous species Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria annae, Oscillatoria chlorina, Oscillatoria curviceps, Oscillatoria okeni, Oscillatoria princeps, Oscillatoria salina, Oscillatoria tenuis, Phormidium corium, Phormdium tenue, Lyngbya limnetica, Lyngbya mesotricha, Lyngbya truncicola, Symploca muscorum have not observed in the 2,4-treated rice fields of Agomoni. The heterocystous filamentous species Cylindrospermum indicum, Nostoc ellipsosporum, Nostoc muscorum, Nostoc spongiaeforme, Anabaena anomala, Anabaena gelatinicola, Anabaena variabilis, Aulosira fertilissima, Scytonema crustaceum, Scytonema multiramosum, Tolypothrix tenuis, Calothrix brevissima, Calothrix marchica, Rivularia hansgirgi and Mastigocladus laminosus could not survive in 2,4-D treated field and found as sensitive to this herbicide in field conditions.

31 Results 67 The 2, 4-D tolerant unicellular species in Agomoni rice fields observed were Microcystis aeruginosa, Chroococcus macrococcus, Chroococcus minutus, Chroococcus tenax, Chroococcus pallidus, Gloeocapsa decorticans, Gloeocapsa magma, Gloeocapsa sanguinea, Gloeothece rhodochlamys, Aphanocapsa banaresensis, Aphanocapsa pulchra, Aphanothece pallida, Synechocystis pevalekii, Merismopedia tenuissima and Stichosiphon sansibaricus. In Agomoni rice fields, twenty six of filamentous blue green algae- Oscilatoria anguina, Oscillatoria chalybea, Oscillatoria nigroviridis, Oscillatoria perornata, Oscillatora princeps, Oscillatoria raoi, Oscillatoria vizagapatensis, Phormidium fragile, Phormidium retzii, Lyngbya aestuarii, Lyngbya major, Lyngbya majuscula, Lyngbya porphyrosiphonis, Nostoc linckia, Nostoc punctiforme, Anabaena ambigua, Anabaena fertilissima, Anabaena sphaerica, Scytonema burmanicum, Tolypothrix byssoidea, Calothrix castellii, Calothrix fusca, Calothrix stellaris, Gloeotrichia intermedia, Gloeotrichia raciborskii and Stigonema turfaceum have been found to grow suitably against 2,4-D herbicide in the fields (Table- 8). In the site-i rice field treated with herbicide 2,4-D the growth of the blue green algae reduced to 41 species (52.56 %) as compared to 78 species of the controlled field. The algaecide value of 2, 4-D was found to be (Table- 11). In Bavistin treated rice fields of Agomoni, ten members of unicellular blue green algae namely Chroococcus cohaerens, Chroococcus macrococcus, Chroococcus tenax, Chroococcus pallidus, Gloeocapsa decorticans, Gloeocapsa nigrescens, Gloeocapsa polydermatica, Gloeothece rhodochlamys, Aphanocapsa pulchra, and Stichosiphon sansibaricus failed to grow. Among the filamentous species 7 members of Oscillatoria like Oscillatoria anguina, Oscillatoria chalybea var. insularis, Oscillatoria nigroviridis, Oscillatoria perornata, Oscillatoria princeps, Oscillatoria raoi, Oscillatoria vizagapatensis; 2 species of Phormidium namely Phormidium fragile and Phormidium retzii, 3 species of Lyngbya like Lyngbya major, Lyngbya majuscula, Lyngbya porphyrosiphonis, 2 species of Nostoc i.e. Nostoc lincka, Nostoc punctiforme, and 4 species of

32 Results 68 Anabaena namely Anabaena ambigua, Anabaena anomala, Anabaena gelatinicola, Anabaena sphaerica, 2 species of Scytonema i.e. Scytonema burmanicum, Scytonema multiramosum, 2 species of Calothrix i.e. Calthrix bravissima, Calothrix castellii and Rivulara hansgirgi, Gloeotrichia intermedia, Stigonema tufaceum that were recorded in the control rice field, but failed to grow in Bavistin treated field. The Bavistin tolerant species in Agomoni rice fields observed were Microcystis aeruginosa, Microcystis flos-aquae, Chroococcus minutus, Gloeocapsa magma, Gloeocapsa sanguinea, Gloeocapsa stegophila, Gloeothece samoensis, Aphanocapsa banaresensis, Aphanocapsa biformis, Aphanothece pallida, Synechocystis pevalekii, Merismopedia tenuissima, Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria annae, Oscillatoria chlorina, Oscillatoria curviceps, Oscillatoria okeni, Oscillatoria princeps var. pseudolimosa, Oscillatoria salina, Oscillatoria tenuis, Phormidium corium, Phormidium tenuue, Lyngbya aestuarii, Lyngbya limnetica, Lyngbya mesotrichia, Lyngbya truncicola, Symploca muscorum. The bavistin tolerant nitrogen fixing blue green algal species in Agomoni field were Cylindrospermum indicum, Nostoc ellipsosporum, Nostoc muscorum, Nostoc spongiaeforme, Anabaena fertilissima, Anabaena variabilis var. ellipsospora, Aulosira fertilissima, Scytonema crustaceum, Tolypothrix byssoidea, Tolypothrix tenuis, Calothrix fusca, Calothrix marchica, Calothrix stellaris, Gloeotrichia raciborskii and Mastigocladus laminosus. In Bavistin treated field 43 spesies (55.12%) of blue green algae members observed as tolerant species at recommended dose. The algaecide value of Bavistin calculated to be in Agomoni rice fields (Tables- 8 and11). In the Malathion treated rice field, 12 unicellular species out of 22 and 28 filamentous species out of 56 members failed to grow. The algal species Microcystis aeruginosa, Microcystis flos-aquae, Chroococcus macrococcus, Chroococcus tenax, Gloeocapsa decorticans, Gloeocapsa nigrescens, Gloeocapsa polydermatica, Gloeocapsa stegophila, Aphanocapsa banaresensis,

33 Results 69 Aphanocapsa pulchra, Synechocystis pevalekii, Merismopedia tenuissima, Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria chalybea, Oscillatoria curviceps, Oscillatoria okeni, Oscillatoria princeps, Oscillatoria raoi, Oscillatoria tenuis, Phormidium fragile, Phormidium retzii, Lyngbya limnetica, Lyngbya major, Lyngbya porphyrosiphonis, Lyngbya truncicola, Nostoc ellipsosporum, Nostoc linckia, Nostoc punctiforme, Anabaena ambigua, Anabaena fertilissima, Anabaena sphaerica, Aulosira fertilissima, Scytonema crustaceum, Tolypothrix byssoidea, Tolypothrix tenuis, Calothrix castellii, Calothrix marchica, Calothrix stellaris and Mastigocladus laminosus could not survive in Malathion. The Malathion tolerant nitrogen fixing blue green algal species in Agomoni rice fields were Cylindrospermum indicum, Nostoc muscorum, Nostoc spongiaeforme, Anabaena anomala, Anabaena gelatinicola, Anabaena variabilis, Scytonema burmanicum, Scytonema mltiramosum, Calothrix brevissima, Calothrix fusca, Rivularia hansgirgi, Gloeotrichia intermedia var. kanwaensis, Gloeotrichia raciborskii and Stigonema turfaceum. Again, 14 species among the non heterocystous filamentous and 10 unicellular species of blue green algae were observed as Malathion tolerant in the Agomoni rice fields at the recommended dose. The Malathion treated rice fields supported the growth of 38 algal species (48.72 %) with algaecide value as (Tables-8 and 11). In Cypermethrin insecticide, 9 out of 22 unicellular blue green algae like Microcystis flos-aquae, Chroococcus minutus, Chroococcus tenax, Gloeocapsa nigrescens, Gloeocapsa sanguinea, Gloeocapsa stegophila, Aphanocapsa banaresensis, Aphanocapsa pulchra and Merismopedia tenuissima found cypermethrin tolerant species in Agomoni fields. Among the filamentous members 25 species out of 56 found to grow in Cypermethrin treated Agomoni rice field. They were Arthrospira spirulinoides, Oscillatoria annae, Oscillatoria chalybea, Oscillatoria nigroviridis, Oscillatoria perornata, Oscillatoria princeps, Oscillatoria tenuis, Oscillatoria vizagapatensis, Phormidium fragile, Lyngbya limnetica, Lyngbya major, Lyngbya porphyrosiphonis, Symploca muscorum are

34 Results 70 the non-heterocystous filamentous and Nostoc ellipsosporum, Nostoc punctiforme, Anabaena anomala, Anabaena fertilissima, Anabaena gelatinicola, Aulosira fertilissima, Scytonema burmanicum, Scytonema mltiramosum, Calothrix fusca, Calothrix marchica, Calothrix stellaris and Gloeotrichia raciborskii were found as cypermethrin tolerant nitrogen fixing blue green algae species in Agomoni rice fields. In Cypermethrin pesticide, 13 species out of 22 unicellular blue green algae (59%) and 31 species out of 56 filamentous forms (55.36%) failed to grow in Agomoni rice fields. Algaecide value of Cypermethrin was found to be (Table-8 and 11). In Agomoni rice fields Chroococcus minutus, Gloeocapsa sanguinea, Calothrix fusca and Gloeotrichia raciborskii were observed as the most resistant blue green algae species which were not hurted by any of 2, 4-D, Bavistin, Malathion or Cypermethrin pesticide in the field condition. Thus in Agomoni rice field Cypermethrin was observed as the highest and Bavistin with the lowest effect on blue green algal occurrence. In the rice fields of Agomoni, the comparative antagonistic effect of all the four pesticides are Cypermethrin > Malathion > 2, 4-D >Bavistin (Fig. 10). Table 8: Tolerant blue green algal species in site-i (Agomoni rice fields) at recommended doses of Pesticides. Sl. No. Name of algal Species Control Site-I: Agomoni rice field 2,4-D BAV MAL CYP Family: Chroococcaceae 1 Microcystis aeruginosa Microcystis flos-aquae Chroococcus cohaerens Chroococcus macrococcus Chroococcus minutus Chroococcus tenax Chroococcus pallidus Gloeocapsa decorticans Gloeocapsa magma Gloeocapsa nigrescens , 4-D: 2, 4-Dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin

35 Results 71 Sl. No. Name of algal Species Control Site-I: Agomoni rice field 2,4-D BAV MAL CYP 11 Gloeocapsa polydermatica Gloeocapsa sanguinea Gloeocapsa stegophila var. crassa Gloeothece rhodochlamys Gloeothece samoensis var. major Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa pulchra Aphanothece pallida Synechocystis pevalekii Merismopedia tenuissima Family: Dermocarpaceae 22 Stichosiphon sansibaricus Family: Oscillatoriaceae 23 Arthrospira spirulinoides Oscillatoria acuta Oscillatoria anguina Oscillatoria annae Oscillatoria chalybea var. insularis Oscillatoria chlorina Oscillatoria curviceps Oscillatoria nigroviridis Oscillatoria okeni Oscillatoria perornata Oscillatoria princeps Oscillatoria princeps var. pseudolimosa Oscillatoria raoi Oscillatoria salina Oscillatoria tenuis Oscillatoria vizagapatensis , 4-D: 2, 4-Dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin

36 Results 72 Sl. No. Name of algal Species Control Site-I: Agomoni rice field 2,4-D BAV MAL CYP 39 Phormidium corium Phormidium fragile Phormidium retzii Phormidium tenue Lyngbya aestuarii Lyngbya limnetica Lyngbya major Lyngbya majuscula Lyngbya mesotricha Lyngbya porphyrosiphonis Lyngbya truncicola Symploca muscorum Family: Nostocaceae 51 Cylindrospermum indicum Nostoc ellipsosporum Nostoc linckia Nostoc muscorum Nostoc punctiforme Nostoc spongiaeforme Anabaena ambigua Anabaena anomala Anabaena fertilissima Anabaena gelatinicola Anabaena sphaerica Anabaena variabilis var. ellipsospora Aulosira fertilissima Family: Scytonemataceae 64 Scytonema burmanicum Scytonema crustaceum Scytonema multiramosum Tolypothrix byssoidea Tolypothrix tenuis ,4-D: 2,4-Dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin

37 Results 73 Sl. No. Name of algal Species Control Site-I: Agomoni rice field 2,4-D BAV MAL CYP Family: Rivulariaceae 69 Calothrix brevissima var. moniliforme Calothrix castellii Calothrix fusca Calothrix marchica Calothrix stellaris Rivularia hansgirgi Gloeotrichia intermedia var. kanwaensis Gloeotrichia raciborskii Family: Mastigocladaceae 77 Mastigocladus laminosus Family: Stigonemataceae 78 Stigonema turfaceum Total ,4-D: 2,4-Dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin Fig. 10: Tolerant blue green algal species in (site-i) at recommended dose

38 Results 74 In the site-ii (i.e. Bilasipara Takimari rice fields), a total of 61 blue green algae were collected from control experimental field and 17 of these were unicellular and 44 filamentous species. In the 2, 4-D treated rice field of Bilasipara 34 tolerant species (55.73%) blue green algae survived in the plot and 27 eliminated due to pesticide application. The 2, 4-D tolerant species in this field were 10 unicellular species Chroococcus cohaerens, Chroococcus indicus, Chroococcus minor, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Gloeocapsa atrata, Gloeothece rupestris, Aphanocapsa banaresensis, Aphanocapsa biformis and Synechocystis aquatilis which were found present in the rice fields. The 2, 4-D tolerant non-heterocystous filamentous blue green algae Oscillatoria anguina, Oscillatoria chalybea var. insularis, Oscillatoria chlorina, Oscillatoria okeni, Oscillatoria salina, Oscillatoria tenuis, Phormidium fragile, Phormidium valderianum, Lyngbya aestuarii, Lyngbya limnetica and Lyngbya truncicola were able to grow in the pesticide treated field. Among the heterocystous species, 13 nitrogen fixing species Cylindrospermum indicum, Nostoc ellipsosporum, Nostoc spongiaeforme, Anabaena anomala, Anabaena iyengarii, Aulosira fritschii in Nostocaceae; Scytonema hofmanni, Scytonema mltiramosum, Tolypothrix byssoidea of Scytonemataceae; Calothrix marchica, Calothrix scytonemicola, Rivularia hansgirgi in Rvulariaceae and Mastigocladus laminosus in Mastigocadaceae were found to grow in the 2,4-D treated experimental rice fields of Bilasipara Takimari rice field. The unicellular species eliminated by 2, 4-D treatment in Site-II rice field were Microcystis aeruginosa, Microcystis flos-aquae, Chroococcus schizodermaticus, Chroococcus turgidus, Gloeocapsa polydermatica, Aphanocapsa pulchra and Aphanothece pallida. Among the filamentous forms Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria curviceps, Oscillatoria limosa, Oscillatoria princeps, Oscillatoria vizagapatensis, Phormidium corium, Phormidium retzii, Lyngbya majuscula, Lyngbya porphyrosiphonis of Oscillatoriaceae; Nostoc muscorum, Nostoc punctiforme, Anabaena doliolum, Anabaena fertilissima, Anabaena oryzae and Anabaena variabilis of Nostocaceae; Scytonema burmanicum and Scytonema schmidtii of Scytonemataceae; Calothrix brevissima var. moniliforme and Gloeotrichia

39 Results 75 intermedia var. kanwaensis of Rivulariaceae did not survive in 2,4-D field experiments. The algaecide value of 2, 4-D in the Bilasipara rice field found to be (Tables-9 and 11). In Bavistin treated Bilasipara rice field, a total of 39 species out of 61 of the controlled blue green algae species (i.e %) found as tolerant in the field condition. The following unicellular blue green algal speces were found as Bvistin resistant in Bilasipara rice field experiments Microcystis aeruginosa, Microcytis flos-aquae, Chroococcus cohaerens, Chroococcus pallidus, Chroococcus turgidus, Gloeocapa atrata, Gloeocapsa polydermatica, Aphanocapsa banaresensis, Aphanocapsa biformis, Aphanocapsa pulchra, Aphanothece pallida. In Bilasipara rice fields 13 Bavistin tolerant simple filamentous blue green algae was observed Arthrospira spirulinoides, Oscillatoria anguina, Oscillatoria chalybea var. insularis, Oscillatoria curviceps, Oscillatoria limosa, Oscillatoria okeni, Oscilltoria salina, Oscillatoria vizagapatensis, Phormidium corium, Phormidium retzii, Phormidium valderianum, Lyngbya aestuarii and Lyngbya porphyrosiphonis. In Bavistin treated rice field of Bilasipara 15 heterocystous species Cylindrospermum indicum, Nostoc muscorum, Nostoc punctiforme, Nostoc spongiaeforme, Anabaena fertilissima, Anabaena oryzae, Anabaena variabilis var. ellipsospora, Scytonema burmanicum, Scytonema hofmanni, Scytonema schmidtii, Tolypothrix byssoidea, Calothrix brevissima var. moniliforme, Calothrix scytonemicola, Gloeotrichia intermedia var. kanwaensis and Mastigocladus laminosus were observed as Bavistin tolerant nitrogen fixing blue green algae (Table-9). In the Bilasipara rice fields 6 unicellular species observed as Bavistin sensitive and were eliminated from field they are Chroococcus indicus, Chroococcus minor, Chroococcus montanus var. hyalinus, Chroococcus schizodermaticus, Gloeothece rupestris and Synechocystis aquatilis. The simple filamentous species that failed to grow in Bavistin field were Oscillatoria acuta, Oscillatoria chlorina, Oscillatoria princeps, Oscillatoria tenuis, Phormidium fragile, Lyngbya limneica, Lyngbya majscula and Lyngbya truncicola. Among the heterocystous filamentous species Nostoc ellisosporum, Anabaena anomala,

40 Results 76 Anabaena doliolum, Anabaena iyengarii var. tenuis, Aulosira fritschii, Scytonema multiramosum, Calothrix marchica and Rivularia hansgirgi could not survive in the Bavistin treated Bilasipara rice field. The algaecide value of Bavistin in Bilasipara rice fields observed as (Table-11). In the rice fields of Bilasipara with Malathion pesticide treatment, 31 species out of 61 (i.e %) were found to tolerate Malathion effect in the experimental field conditions at recommended dose. Among these 9 unicellular species Microcystis flos-aquae, Chroococcus minor, Chroococcus montanus var. hyalinus, Chroococcus schizodermaticus, Gloeocapsa atrata, Gloeothece rupestris, Aphanocapsa biformis, Aphanothece pallida and Synechocystis aquatilis were found Malathion tolerant in field conditions. The 12 simple filamentous blue green algae that could suvive in Malathon treated rice fields are Arthrospira spirulinoides, Oscillatoria anguina, Oscillatoria chlorina, Oscillatoria limosa, Oscillatoria tenuis, Oscillatoria vizagapatensis, Phormidium fragile, Phormidium retzii, Phormidium valderianum, Lyngbya limnetica, Lyngbya majuscula and Lyngbya truncicola. The Malathion tolerant heterocystous filamentous blue green algae species observed were Nostoc ellipsosporum, Nostoc spongiaeforme, Anabaena anomala, Anabaena iyengarii var. tenuis, Anabaena oryzae, Aulosira fritschii, Scytonema schmidtii, Calothrix marchica, Calothrix scytonemicola and Mastigocladus laminosus. In Site-II experimental rice fields following blue green algae were eliminated at recommended Malathion dose Microcystis aeruginosa, Chroococcus cohaerens, Chroococcus indicus, Chroococcus pallidus, Chroococcus turgidus, Gloeocapsa polydermatica, Aphanocapsa banaresensis, Aphanocapsa pulchra of unicellular type; Oscillatoria acuta, Oscillatoria chalybea var. insularis, Oscillatoria curviceps, Oscillatoria okeni, Oscillatoria princeps, Oscillatoria salina, Phormidium corium, Lyngbya aestuarii, Lyngbya porphyrosiphonis belonged to simple filamentous species. Among the heterocystous filamentous species Cylindrospermum indicum, Nostoc muscorum, Nostoc punctiforme, Anabaena doliolum, Anabaena fertilissima, Anabaena variabilis var. ellipsospora, Scytonema burmanicum, Scytonema hofmanni,

41 Results 77 Scytonema multiramosum, Tolypothrix byssoidea, Calothrix brevissima var. moniliforme, Rivularia hansgirgi, Gloeotrichia intermedia var. kanwaensis, were not found to grow in Malathion treated experimental fields of site-ii. The algaecide value of Malathion in Bilasipara Takimari rice field was found to be as in field conditions (Table-9 &11). In the Bilasipara rice fields treated with Cypermethrin, there observed 32 Cypermethrin tolerant blue green algae species that were able to survive against the pesticide as compared to 61 species in controlled experimental rice field. Here, 11 unicellular species of blue green algae were observed as Cypermethrin tolerant; they are Chroococcus cohaerens, Chroococcus indicus, Chroococcus montanus var. hyalinus, Chroococcus schizodermaticus, Chroococcus turgidus, Gloeocapsa atrata, Gloeocapsa polydermatica, Gloeothece rupestris, Aphanocapsa banaresensis, Aphanocapsa biformis and Synechocystis aquatilis. In the fields 9 species of simple flamentous members like Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria chlorina, Oscillatoria curviceps, Oscillatoria limosa, Oscillatoria tenuis, Phormidium fragile, Phormidium valderianum and Lyngbya porphyrosiphonis found as Cypermethrin tolerant. The Cypermethrin tolerant heterocystous blue green algae in Bilasipara rice fields found are Cylindrospermum indicum, Nostoc ellipsosporum, Nostoc muscorum, Nostoc spongiaeforme, Anabaena fertilissima, Anabaena iyengarii var. tenuis, Aulosira fritschii, Scytonema hofmanni, Scytonema multiramosum, Scytonema schmidtii, Calothrix brevissima var. moniliforme, Calothrix marchica which were able to grow in fields against Cypermethrin effect. The eliminated blue green algae species in Cyperthrin treated rice fields of site-ii were Microcystis aeruginosa, Microcystis flos-aquae, Chroococcus pallidus, Chroococcus minor, Aphanocapsa pulchra, Aphanothece pallida among the unicellular species. Among the simple filamentous species Oscillatoria anguina, Oscillatoria chalybea var. insularis, Oscillatoria okeni, Oscillatoria princeps, Oscillatoria salina, Oscillatoria vizagapatensis, Phormidium corium, Phormidium retzii, Lyngbya aestuarii, Lyngbya limnetica, Lyngbya majuscula and Lyngbya truncicola were found affected. The heterocytous filamentous

42 Results 78 species Nostoc punctiforme, Anabaena doliolum, Anabaena oryzae, Anabaena variabilis var. ellipsospora, Scytonema burmanicum, Tolypothrix byssoidea, Calothrix scytonemicola, Rivularia hansgirgi and Mastigocladus laminosus could not grow in the Cypermethrin treated rice fields of Bilasipara. The algaecide value of cypermethrin was found to be in the Bilasipara rice fields (Table- 9, Fig. 11). In Bilasipara rice fields Gloeocapsa atrata, Aphanocapsa biformis, Phormidium valderianum and Nostoc spongiaeforme were observed as the pesticide tolerant blue green algae species which were not hurted by any of 2, 4-D, Bavistin, Malathion or Cypermethrin pesticide in the field condition. Table 9: Tolerant blue green algal species in site-ii (Bilasipara rice fields) at Sl. No. recommended dose of Pesticides. Family: Chroococcaceae Name of Species Control Site-II: Bilasipara rice field 2,4-D BAV MAL CYP 1 Microcystis aeruginosa Microcystis flos-aquae Chroococcus cohaerens Chroococcus indicus Chroococcus minor Chroococcus montanus var. hyalinus Chroococcus pallidus Chroococcus schizodermaticus Chroococcus turgidus Gloeocapsa atrata Gloeocapsa polydermatica Gloeothece rupestris Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa pulchra Aphanothece pallida Synechocystis aquatilis , 4-D: 2, 4-dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin

43 Results 79 Sl. No. Family: Oscillatoriaceae Name of Species Control Site-II: Bilasipara rice field 2,4-D BAV MAL CYP 18 Arthrospira spirulinoides Oscillatoria acuta Oscillatoria anguina Oscillatoria chalybea var. insularis Oscillatoria chlorina Oscillatoria curviceps Oscillatoria limosa Oscillatoria okeni Oscillatoria princeps Oscillatoria salina Oscillatoria tenuis Oscillatoria vizagapatensis Phormidium corium Phormidium fragile Phormidium retzii Phormidium valderianum Lyngbya aestuarii Lyngbya limnetica Lyngbya majuscula Lyngbya porphyrosiphonis Lyngbya truncicola Family: Nostocaceae 39 Cylindrospermum indicum Nostoc ellipsosporum Nostoc muscorum Nostoc punctiforme Nostoc spongiaeforme Anabaena anomala Anabaena doliolum Anabaena fertilissima Anabaena iyengarii var. tenuis Anabaena oryzae Anabaena variabilis var. ellipsospora Aulosira fritschii , 4-D: 2, 4-Dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin

44 Results 80 Sl. No. Name of Species Family: Scytonemataceae Control Site-II: Bilasipara rice field 2,4-D BAV MAL CYP 51 Scytonema burmanicum Scytonema hofmanni Scytonema multiramosum Scytonema schmidtii Tolypothrix byssoidea Family: Rivulariaceae 56 Calothrix brevissima var. moniliforme Calothrix marchica Calothrix scytonemicola Rivularia hansgirgi Gloeotrichia intermedia var. kanwaensis Family: Mastigocladaceae 61 Mastigocladus laminosus Total ,4-D: 2,4-dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; + indicate tolarent species, - indicate elimination of species CYP: Cypermethrin Fig. 11: Tolerant blue green algal species in site-ii (Bilasipara rice fields) at recommended dose

45 Results 81 In Jarua rice fields a total of 69 blue green algae were observed in control field. The rice fields treated with 2,4-D only 34 blue green algae were observed to grow. The 2,4-D tolerant unicellular blue green algae species in Jarua Bandihana rice fields observed were Microcystis pulverea var. incerta, Chroococcus cohaerens, Chroococcus minutus, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Gloeocapsa nigrescens, Gloeocapsa quaternata, Gloeothece rupestris, Aphanocapsa biformis, Aphanothece stagnina, Myxosarcina burmensis in the field conditions. Among the simple filamentous species Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria limosa, Oscillatoria perornata, Oscillatoria princeps var. pseudolimosa, Oscillatoria raoi, Oscillatoria salina, Phormidium lucidum, Lyngbya aestuarii, Lyngbya limnetica, Lyngbya major, Lyngbya mesotricha were present in 2, 4-D treated rice fields. Among heterocystous species Cylindrospermum indicum, Nostoc ellipsosporum, Nostoc spongiaeforme, Anabaena anomala and Anabaena fertilissima in Nostocaceae were observed 2, 4-D tolerant species. In Scytonemataceae, Tolypothrix tenuis, Scytonema crustaceum and Scytonema crustaceum were found to grow in the 2, 4-D treated rice fields. Gloeotrichia natans, Calothrix scytonemicola, Calothrix castellii of Rivulariaceae were observed as 2, 4-D tolerant species in the rice fields. In the 2, 4-D treated rice fields of Jarua 35 species out of 69 blue green algae in the controlled field failed to grow. The 14 unicellular species that could not tolerate 2, 4-D effect in fields were Microcystis bengalensis, Chroococus macrococcus, Chroococus turgidus, Gloeocapsa decorticans, Gloeocapsa magma, Gloeocapsa polydermatica, Gloeocapsa stegophila, Gloeothece samoensis, Aphanocapsa banaresensis, Aphanocapsa pulchra, Aphanothece pallida, Synechocystis pevalekii, Merismopedia tenuissima and Chlorogloea fritschii. In the 2, 4-D fields 7 simple filamentous species could not tolerate 2, 4-D. The species Oscillatoria chalybea, Oscillatoria chlorina, Oscillatoria curviceps, Phormidium corium, Lyngbya porphyrosiphonis, Lyngbya truncicola and Symploca cartilaginea were not observed in the pesticide treated field. Among the heterocyst bearing species 6 species in Nostocaceae i.e. Nostoc calcicola, Nostoc linckia, Nostoc muscorum, Anabaena gelatinicola, Anabaena

46 Results 82 iyengarii and Anabaena sphaerica; 1 species in Scytonemataceae- Scytonema multiramosum; 6 species in Rivulariaceae i.e. Calothrix brevissima, Calothrix marchica, Calothrix stellaris, Gloeotrichia pilgeri, Gloeotrichia intermdia and Gloeotrichia raciborskii and the species Mastigocladus laminosus of Mastigocladaceae were not found to grow in 2, 4-D pesticide treated experimental fields. In Jarua Bandihana rice fields the algaecide value of 2, 4-D was found as (Tables-10 & 11). Site-III Jarua rice fields, 13 unicellular members were found as Bavistin tolerant species, they are Microcystis bengalensis, Microcystis pulverea var. incerta, Chroococcus macrococcus, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Gloeocapsa magma, Gloeocapsa nigrescens, Gloeocapsa stegophila, Aphanocapsa banaresensis, Aphanocapsa biformis, Aphanothece pallida, Aphanothece stagnina and Chlorogloea fritschii. The Bavistin tolerant simple filamentous species observed were Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria chalybea var. insularis, Oscillatoria curviceps, Oscillatoria limosa, Oscillatoria raoi, Phormidium corium, Lyngbya major, Lyngbya mesotricha and Lyngbya truncicola. In field condidion the heterocystous species Cylindrospermum indicum, Nostoc calcicola, Nostoc linckia, Nostoc muscorum, Nostoc spongiaeforme, Anabaena anomala, Anabaena fertilissima, Scytonema hofmanni, Tolypothrix tenuis, Calothrix brevissima var. moniliforme, Calothrix castellii, Calothrix marchica, Calothrix stellarii, Gloeotrichia intermedia var. kanwaensis, Gloeotrichia raciborskii and Mastigocladus laminosus were observed as Bavistin tolerant species in the Jarua rice fields. The Bavistin sensitive blue green algae species in Site-III fields that could not grow were Chroococcus cohaerens, Chroococcus minutus, Chroococcus turgidus, Gloeocapsa decorticans, Gloecapsa polydermatica, Gloeocapsa quaternata, Gloeothece rupestris, Gloeothece samoensis, Aphanocapsa pulchra, Synechocystis pevalekii, Merismopedia tenuissima and Myxosarcina bumensis among the unicellular members. The simple filamentous species Oscillatoria chlorina, Oscillatoria perornata, Oscillatoria princeps var. pseudolimosa, Oscillatoria salina, Phormidium lucidum, Lyngbya aestuarii, Lyngbya limnetica,

47 Results 83 Lyngbya porphyrosiphonis and Symploca cartilaginea found as Bavistin sensitive and could not grow in the Bavistin treated field. The heterocystous blue green algal species like Nostoc ellipsospoum, Anabaena gelatinicola, Anabaena iyengarii var. tenuis, Anabaena sphaerica, Scytonema crustaceum, Scytonema multiramosum, Calothrix scytonemicola, Gloeotrichia pilgeri, and Gloeotrichia natans could not survive in the Bavistin treated Jarua rice fields (Table-10). In Site-III (Jarua Bandihana) rice fieds the algaecide value of Bavistin was found as (Table-11). In Site-III experimental rice fields with Malathion pesticide treatment, the unicellular species Microcystis bengalensis, Microcystis pulverea var. incerta, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Gloeocapsa nigrescens, Gloeothece rupestris, Gloeothece samoensis var. major, Aphanocapsa biformis, Aphanothece pallida, Aphanothece stagnina, Synechocystis pevaleki, Chlorogloea fritschii and Myxosarcina burmensis were observed tolerant to recommended dose of Malathion. Among the simple filamentous species Oscillatoria acuta, Oscillatoria chlorina, Oscillatoria perornata, Lyngbya limnetica, Lyngbya major, Lyngbya mesotricha were found to resist the pesticide effect of Malathion. The heterocyst bearing species Cylindrospermum indicum, Nostoc linckia, Nostoc spongiaeforme, Anabaena anomala, Anabaena fertilissima, Anabaena iyengarii var. tenuis, Scytonema hofmanni, Calothrix marchica, Gloeotrichia intermedia var. kanwaensis, Gloeotrichia pilgeri, Gloeotrichia raciborskii and Mastigocladus laminosus were found as tolerant species against recommended dose Malation in Jarua Bandihana rice fields. The blue green algae species that failed to survive in Malathion pesticide treated fields of site-iii were Chroococcus cohaerens, Chroococcus macrococcus, Chroococcus minutus, Chroococcus turgidus, Gloeocapsa decorticans, Gloeocapsa magma, Gloeocapsa polydermatica, Gloeocapsa stegophila, Gloeocapsa quaternata, Aphanocapsa banaresensis, Aphanocapsa pulchra and Merismopedia tenuissima were among the unicellular members. The filamentous species Arthrospira spirulinoides, Oscillatoria chalybea var.

48 Results 84 insularis, Oscillatoria curviceps, Oscillatoria limosa, Oscillatoria princeps var. pseudolimsa, Oscillatoria raoi, Oscillatoria salina, Phormidium corium, Phormidium lucidum, Lyngbya aestuarii, Lyngbya porphyrosiphonis, Lyngbya truncicola and Symploca cartiliginea could not tolerate the Malathion effect in rice field conditions of Site-III study area. The heterocystous species Nostoc calcicola, Nostoc ellipsosporum, Nostoc muscorum, Anabaena gelatinicola, Anabaena sphaerica, Scytonema crustaceum, Scytonema multiramosum, Tolypothrix tenuis, Calothrx bevissima var. moniliforme, Calothrx castellii, Calothrx scytonemicla, Calothrx stellaris and Gleotrichia natans could not survive in Malathion treated rice fields of site-iii. In this field algaecide value of Malathion was found (Table-10 and 11). Site-III rice fields treated with Cypermethrin pesticide 31 species could tolerate the pesticide effect among 69 blue green algae species of the controlled experimental feld. The tolerant blue green algal species Microcystis pulverea var. incerta, Chroococcus cohaerens, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Gloeocapsa nigrescens, Gloeocapsa polydermatica, Gloeocapsa stegophila, Gloeothece rupestris, Gloeothece samoensis var. major, Aphanocapsa biformis, Aphanothece stagnina, Synechocystis pevalekii, Myxosarcina burmensis were among the unicellular species. In simple filamentous forms Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria curviceps, Oscillatoria perornata, Phormidium corium, Lyngbya aestuarii, Lyngbya mesotricha and Lyngbya truncicola observed as tolerant. The heterocystous species Cylindrospermum indicum, Nostoc spongiaeforme, Anabaena fertilissima, Anabaena iyengarii var. tenuis, Scytonema hofmanni, Calothrix brevissima var. moniliforme, Calothrix marchica, Calothrix stellaris, Gloeotrichia natans and Gloeotrichia raciborskii were found as the Cypermethrin tolerant blue green algae in rice field conditions. Species that could not tolerate the Cypermethrin effect in site-iii rice fields were Microcystis bengalensis, Chroococcus macrococcus, Chroococcus minutus, Chroococcus turgidus, Gloeocapsa dcorticans, Gloeocapsa magma, Gloeocapsa quaternata, Aphanocapsa banaresensis, Aphanocapsa pulchra,

49 Results 85 Aphanothece pallida, Merismopedia tenuissima and Chlorogloea fritschii belonged to unicellular blue geen algae. The simple filamentous blue green algae species Oscillatoria chalybea var. insularis, Oscillatoria chloina, Oscillatoria limosa, Oscillatoria princeps var. pseudolimosa, Oscillatoria raoi, Oscillatoria salina, Lyngbya limnetica, Lyngbya major, Lyngbya porphyrosiphonis and Symploca cartilaginea observed as tolerant. The Cypermethrin sensitive heterocystous blue green algae that could not survive in fields observed are Nostoc calcicola, Nostoc ellipsosporum, Nostoc linckia, Nostoc muscorum, Anabaena anomala, Anabaena gelatnicola, Anabaena sphaerica, Scytonema crustaceum, Scytonema multiramosum, Tolypothrix tenuis, Calothrix castellii, Calothrix scytonemicola, Gloeotrichia intermedia var. kanwaensis, Gloeotrichia pilgeri and Mastigocladus laminosus. Among the simple filamentous species Oscillatoria chalybea, Oscillatoria chlorina, Oscillatoria limosa, Oscillatoria princeps var. pseudolimosa, Oscillatoria raoi, Oscillatoria salina, Phormidium lucidum, Lyngbya limnetica, Lyngbya major, Lyngbya porphyrosiphonis and Symploca cartiliginea could not survive in Cypermethrin treated rice field. The unicellular species Microcystis bengalensis, Chroococcus macrococcus, Chroococcus minutus, Chroococcus turgidus, Gloeocapsa decorticans, Gloeocapsa magma, Gloeocapsa quaternata, Aphanocapsa banaresensis, Aphanocapsa pulchra, Aphanothece pallida, Merismopedia tenuissima and Chlorogloea fritschii were observed as Cypermethrin sensitive species in the Jarua rice fields that could not survive. The algaecide value of Cypermethrin in Jarua Bandihana rice fields was observed as (Table- 10). In Jarua rice fields Microcystis pulverea var. incerta, Chroococcus montanus var. hyalinus, Chroococcus pallidus, Gloeocapsa nigrescens, Aphanocapsa biformis, Aphanothece stagnina, Oscillatoria acuta, Lyngbya mesotricha, Cylindrospermum indicum, Nostoc spongiaeforme were observed as the pesticide tolerant blue green algae species which were not hurted by any of 2, 4-D, Bavistin, Malathion or Cypermethrin pesticide in the field condition. In the Jarua rice fields both Cypermethrin and Malathion have equal antagonistic effect on the growth of blue green algae which observed as highest

50 Results 86 effect followed by 2, 4-D and Bavistin was observed with lowest pesticide effect on the occurrence of rice field blue green algae in the Jarua rice field. The antagonistic effect of all these treated pesticides in the site-iii was in the order of Cypermethrin = Malathion > 2, 4-D > Bavistin (Tables-10 and 11, fig.12). Table 10: Tolerant blue green algal species in site-iii (Jarua rice fields) at recommended doses Sl. No. Name of Species Control Site-III: Jarua rice fields 2,4-D BAV MAL CYP Family: Chroococcaceae 1 Microcystis bengalensis Microcystis pulverea var. incerta Chroococcus cohaerens Chroococcus macrococcus Chroococcus minutus Chroococcus montanus var. hyalinus Chroococcus pallidus Chroococcus turgidus Gloeocapsa decorticans Gloeocapsa magma Gloeocapsa nigrescens Gloeocapsa. polydermatica Gloeocapsa stegophila var. crassa Gloeocapsa quaternata Gloeothece rupestris Gloeothece samoensis var. major Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa pulchra Aphanothece pallida Aphanothece stagnina Synechocystis pevalekii Merismopedia tenuissima , 4-D: 2, 4-dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin.

51 Results 87 Sl. No. Name of Species Control Site-III: Jarua rice fields 2,4-D BAV MAL CYP Family: Entophysalidaceae 24 Chlorogloea fritschii Family: Pleurocapsaceae 25 Myxosarcina burmensis Family: Oscillatoriaceae 26 Arthrospira spirulinoides Oscillatoria acuta Oscillatoria chalybea var. insularis Oscillatoria chlorina Oscillatoria curviceps Oscillatoria limosa Oscillatoria perornata Oscillatoria princeps var. pseudolimosa Oscillatoria raoi Oscillatoria salina Phormidium corium Phormidium lucidum Lyngbya aestuarii Lyngbya limnetica Lyngbya major Lyngbya mesotricha Lyngbya porphyrosiphonis Lyngbya truncicola Symploca cartilaginea Family: Nostocaceae 45 Cylindrospermum indicum Nostoc calcicola Nostoc ellipsosporum , 4-D: 2, 4-dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin.

52 Results 88 Sl. No. Name of Species Control Site-III: Jarua rice fields 2,4-D BAV MAL CYP 48 Nostoc linckia Nostoc muscorum Nostoc spongiaeforme Anabaena anomala Anabaena fertilissima Anabaena gelatinicola Anabaena iyengarii var. tenuis Anabaena sphaerica Family: Scytonemataceae 56 Scytonema crustaceum Scytonema hofmanni Scytonema multiramosum Tolypothrix tenuis Family: Rivulariaceae 60 Calothrix brevissima var. moniliforme Calothrix castellii Calothrix marchica Calothrix scytonemicola Calothrix stellaris Gloeotrichia intermedia var. kanwaensis Gloeotrichia pilgeri Gloeotrichia natans Gloeotrichia raciborskii Family: Mastigocladaceae 69 Mastigocladus laminosus Total ,4-D: 2,4-dichlorophenoxy acetic Acid; BAV: Bavistin; MAL: Malathion; CYP: Cypermethrin.

53 Results 89 Fig. 12: Tolerant blue green algal species in site-iii (Jarua rice fields) at recommended doses Table 11: Survival % of algal species and algaecide value of different pesticides in fields Algal species in Site 2,4-D Bav Mala Cyper Control field Site-Agomoni rice fields No. survival algal species Survival percentage of algae No of eliminated algal species Algaecide value of pesticide Site-Bilasipara rice fields No. survival algal species Survival percentage of algae No of eliminated algal species Algaecide value of pesticide Site-Jarua rice fields No. survival algal species Survival percentage of algae No of eliminated algal species Algaecide value of pesticide

54 Results 90 Table 12: One-way ANOVA showing the station wise variation of effect of pesticides on algae for 3 independent field trial Sites (Station) A. Pesticide tolerant algae in rice fields Pesticides No. of survival algae species in rice fields Site-I(Agomoni) Site-II(Bilasipara) Site-III(Jarua) 2,4-D Bavistin Malathion Cypermethrin Statistical analysis was done employing one-way ANOVA test from the above data showing station wise variation of pesticide effect on blue green algae. B. Data summary Sample Site-I Samples Sample Site-II Sample Site-III Total N X Mean X Variance Std.Dev Std.Err C : ANOVA Summary Sum of square df Meansquare F P Treatment [between * groups] Error Total P = , P > So, we can conclude that there is no station-wise variation on effects of pesticides on algae for three independent field trial stations. The analysis of variance shows no significance.

55 Results 91 Table 13: One-way ANOVA test showing the effect of pesticides on different station algae. A. Pesticide effect on survival of algae in fields : Station Pesticide-1 Pesticide-2 Pesticide-3 Pestcide-4 (2,4-D) (Bavistin) (Malathion) (Cypermthrin) Agomoni field Bilasipara field Jarua field B. Data Summary Samples Total N X Mean X Variance Std.Dev Std.Err C. ANOVa Summary Source Treatment [Between groups] Sum of squares df Mean square Error Total * non significant, ** significant The one-way ANOVA analysis of variance shows non significant between the groups for pesticide effect on algae where P > 0.05 F P *

56 Results 92 4.C.1 Effect of 2,4-D on blue green algae in laboratory condition In laboratory conditions, growth of blue green algae shows remarkable change in different concentrations of 2, 4-D. In control a total of 84 species of blue green algae appeared of which 26 belongs to Chroococcaceae, 28 to Oscillatoriaceae, 14 to Nostocaceae, 5 to Scytonemataceae, 8 species to Rivulariaceae and one each to Dermocarpaceae, Mastigocladaceae and Stigonemataceae respectively. All the algal species appeared after days of incubation period. The survival percentage of blue green algae in 6 different concentrations of 2,4-D treated culture were 70.23, 60.71, 38.09, 21.42, 5.95 and 2.38 % at 50 ppm, 100 ppm, 200 ppm, 400 ppm, 600 ppm and 800 ppm respectively. The mean survival percentage was Accordingly the algaecide value of the above ppm concentrations of 2, 4-D were , , , , and in the laboratory culture experiments. The mean algaecide value of 2,4-D was found as Most of the unicellular species survived well in lower concentration of 2, 4-D, but higher concentration it proved fatal. In different families of blue green algae, out of 26 members of the family Chroococcaceae 19 species (73.07 %) successfully grown in 50 ppm, 17 species (65.38%) survived in 100 ppm, 10 species (38.46%) in 200 ppm concentration, 6 species (23.07%) survived at 400 ppm and in 600 ppm of 2, 4-D only Gloeocapsa sanguinea found to grow among the unicellular species of blue green algae that screened. None of the species in Chroococcaceae were observed to grow in the 800 ppm of 2, 4-D. Among all filamentous members, 39 species out 57 species (68.42 %) found to grow at 50 ppm; 33 out of 57 species (57.89%) survived at 100 ppm., 22 species (38.60%) survived in 200 ppm, 12 species (21.05%) in 400 ppm, 4 species (7.01%) in 600 ppm and only two species (3.5%) namely Oscillatoria acuta and Lyngbya limnetica of Oscillatoriaceae found to be tolerant species upto 800 ppm of 2, 4-D pesticide and observed as tolerant blue green algae species in different concentrations of 2,4-D. Among the heterocystous forms in Nostocceae 9 species out of 14 (64.29%) observed tolerant in 50 ppm 2, 4-D pesticide; 6 species (42.86%) survived in 100 ppm, 5 species (35.71%) in 200 ppm 2, 4-D and only 3 species (21.43%) in 400 ppm found as tolerant species. In the family

57 Results 93 Scytonemataceae only one species namely Scytonema multiramosum observed as tolerant species upto 400 ppm 2, 4-D out of 5 species; in Rivulariaceae family Clothrix stellaris and Gloeotrichia intermedia tolerated 400 ppm concentration of 2, 4-D. It is seen that an average of 33.13% of the screened blue green algal species could survive at the 6 different ppm concentration of 2, 4-D. Again 7 unicellular members out of 27 (i.e %), 7 simple filamentous species out of 28 species (25%) of control experiment in Oscillatoriaceae, the filamentous heterocystous members like Nostoc linckia, Anabaena fertilissima, Anabaena oryzae, Anabaena variabilis, Aulosira fritschii in the family of Nostocaceae; Tolypothrix byssoidea in Scytonemataceae, Calothrix castellii, Clothrix marchica, Calothrix scytonemicola, Gloeotrichia raciborskii of Rivulariaceae; Mastigocladus laminosus in the family Mastigocladaceae observed as very susceptible to 2, 4-D which could not tolerate any concentration of 2, 4-D tested in the laboratory. (Tables 14 &15, Fig. 13) Table 14: Tolerant blue green algal species in different concentration of 2,4-D Sl. 2, 4-D (ppm) Name of Species Control No Family- Chroococcaceae 1 Microcystis aeruginosa Microcystis flos-aquae Chroococcus cohaerens Chroococcus indicus Chroococcus macrococcus Chroococcus minor Chroococcus montanus forma Chroococcus montanus var. hyalinus Chroococcus pallidus Chroococcus turgidus Gloeocapsa atrata Gloeocapsa. decorticans Gloeocapsa magma , 4-D: 2, 4-dichlorophenoxy acetic Acid

58 Results 94 Sl. No. Name of Species Control 2, 4-D (ppm) Gloeocapsa nigrescens Gloeocapsa polydermatica Gloeocapsa sanguinea Gloeocapsa stegophila var. crassa Gloeothece rupestris Gloeothece samoensis var. major Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa pulchra Aphanothece pallida Aphanothece stagnina Synechocystis pevalekii Merismopedia tenuissima Family: Dermocarpaceae 27 Stichosiphon sansibaricus Family: Oscillatoriaceae 28 Arthrospira spirulinoides Spirulina gigantea Spirulina princeps Oscillatoria acuta Oscillatoria chalybea var insularis 33 Oscillatoria chlorina Oscillatoria curviceps Oscillatoria limosa Oscillatoria okeni Oscillatoria perornata Oscillatoria princeps Oscillatoria princeps var. pseudolimosa , 4-D: 2, 4-dichlorophenoxy acetic Acid

59 Results 95 Sl. No. Name of Species Control 2, 4-D (ppm) Oscillatoria raoi Oscillatoria salina Oscillatoria tenuis Oscillatoria vizagapatensis Phormidium corium Phormidium fragile Phormidium retzii Phormidium valderianum Lyngbya aestuarii Lyngbya limnetica Lyngbya major Lyngbya majuscula Lyngbya mesotricha Lyngbya porphyrosiphonis Lyngbya truncicola Symploca muscorum Family-Nostocaceae 56 Cylindrospermum indicum Nostoc ellipsosporum Nostoc linckia Nostoc muscorum Nostoc punctiforme Nostoc spongiaeforme Anabaena anomala Anabaena doliolum Anabaena fertilissima Anabaena iyengarii var. tenuis Anabaena oryzae Anabaena sphaerica , 4-D: 2, 4-dichlorophenoxy acetic Acid

60 Results 96 Sl. No. Name of Species Control 2, 4-D (ppm) Anabaena variabilis var. ellipsospora Aulosira fritschii Family: Scytonemataceae 70 Scytonema burmanicum Scytonema hofmanni Scytonema multiramosum Scytonema schmidtii Tolypothrix byssoidea Family: Rivulariaceae 75 Calothrix brevissima var. moniliforme Calothrix castellii Calothrix marchica Calothrix scytonemicola Calothrix stellaris Rivularia hansgirgi Gloeotrichia intermedia var. kanwaensis Gloeotrichia raciborskii Family: Mastigocladaceae 83 Mastigocladus laminosus Family: Stigonemataceae 84 Stigonema lavardei Total ,4-D: 2,4-dichlorophenoxy acetic Acid

61 Results 97 Fig. 13: Tolerant blue green algal species in different concentration of 2,4-D Table 15: Survival percentage of blue green algal species in different concentrations of 2, 4-D with their respective algaecide value No. of Mean of No. of Concentration Survival Algaecide survival Survival eliminated of 2,4-D (ppm) percentage value species percentage species Mean Algaecide value C. 2: Effect of Bavistin on Blue green algae In laboratory experiment it was observed that the normal growth and development of blue green algae affected by Bavistin in different concentrations of Bavistin. Its higher doses become toxic for some members of blue green algae. The survival value of blue green algal members against 50 ppm, 100 ppm, 200 ppm, 400 ppm, 600 ppm and 800 ppm concentrations of Bavistin found as 71.42%, 50%, 32.14%, %, % and 4.762% respectively in laboratory

62 Results 98 treatment. In average % species survived in Bavistin, the average algaecide value found to be In 50 ppm Bavistin 60 species out of 84 were found to occur, thus per cent algae viable. In 50 ppm Bavistin concentration pesticide media solution 20 unicellular species of Chroococcaceae %, Oscillatoriaceae 78.57% and among the heterocystous species, Nostocaceae 42.85%, Scytonemataceae 80%, and in the family Rivulariaceae 75% and all species of Mastigocladaceae and Stigonemataceae could survived. In Bavistin 100 ppm concentration in the laboratory experiment 42 species out of 84 species (50%) in control laboratory experiment, blue green algae species could tolerate the concentration. Comparative tolerance of different blue green algal members against 100 ppm Bavistin observed Oscillatoriaceae (53.84%), Chroococcaceae (65.38%) Scytonemataceae (40%), Rivulariaceae (37.5%) and Nostocaceae (28.57%). Further elimination of algal species was observed as the Bavistin concentration increased. In 200 ppm Bavistin pesticide solution 27 species were recorded as tolerant and the algaecide value found In different families, 34.61% of Chroococcaceae, 50% of Oscillatoriaceae, 7.14% of Nostocaceae, 20% Scytonemataceae, and 25% of Rivulariaceae representatives found as tolerant species. In 400 ppm strength of Bavistin solution, the survival of various species among different families observed Oscillatoriaceae (39.29%), Scytonemataceae (20%), Chroococcaceae (19.23 %), and Rivulariaceae (12.5%) and in Nostocaceae it was only 7.14%. The algaecide value of 400 ppm Bavistin was calculated as In 600 ppm Bavistin concentration Chroococcus minor, Gloeocapsa magma, Synechocystis pevalekii in Chroococcaceae; Arthrospira spirulinoides, Oscillatoria chlorina, Oscillatoria salina, Oscillatoria vizagapatensis, Lyngbya limnetica, Lyngbya porphyrosiphonis were found to grow representing 10.71% tolerance. Algaecide value of 600 ppm Bavistin observed In the 800 ppm Bavistin solution, only 4 species namely Chroococcus minor of Chroococcaceae, Oscillatoria chlorina, Lyngbya limnetica and Lyngbya porphyrosiphonis of Oscillatoriaceae (14.28%) found to survive against 800 ppm Bavistin tested in laboratory, The algaecide value of 800 ppm Bavistin The mean algaecide value of tested in 6 concentrations of Bavistin was found as in laboratory conditions. (Table 16, 17; Fig-14)

63 Results 99 Table 16: Tolerant blue green algal species in different concentrations of Bavistin Sl. Bavistin (ppm) Name of Species Control No Family-Chroococcaceae 1 Microcystis aeruginosa Microcystis flos-aquae Chroococcus cohaerens Chroococcus indicus Chroococcus macrococcus Chroococcus minor Chroococcus montanus forma Chroococcus montanus var. hyalinus Chroococcus pallidus Chroococcus turgidus Gloeocapsa atrata Gloeocapsa decorticans Gloeocapsa magma Gloeocapsa nigrescens Gloeocapsa. polydermatica Gloeocapsa. sanguinea Gloeocapsa stegophila var. crassa Gloeothece rupestris Gloeothece samoensis var. major Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa pulchra Aphanothece pallida Aphanothece stagnina Synechocystis pevalekii ppm : parts per million

64 Results 100 Sl. Bavistin (ppm) Name of Species Control No Merismopedia tenuissima Family: Dermocarpaceae 27 Stichosiphon sansibaricus Family: Oscillatoriaceae 28 Arthrospira spirulinoides Spirulina gigantea Spirulina princeps Oscillatoria acuta Oscillatoria chalybea var. insularis Oscillatoria chlorina Oscillatoria curviceps Oscillatoria limosa Oscillatoria okeni Oscillatoria perornata Oscillatoria princeps Oscillatoria princeps var. pseudo-limosa Oscillatoria raoi Oscillatoria salina Oscillatoria tenuis Oscillatoria vizagapatensis Phormidium corium Phormidium fragile Phormidium retzii Phormidium valderianum Lyngbya aestuarii Lyngbya limnetica Lyngbya major Lyngbya majuscula Lyngbya mesotricha Lyngbya porphyrosiphonis ppm : parts per million

65 Results 101 Sl. Bavistin (ppm) Name of Species Control No Lyngbya truncicola Symploca muscorum Family: Nostocaceae 56 Cylindrospermum indicum Nostoc ellipsosporum Nostoc linckia Nostoc muscorum Nostoc punctiforme Nostoc spongiaeforme Anabaena anomala Anabaena doliolum Anabaena fertilissima Anabaena iyengarii var. tenuis Anabaena oryzae Anabaena sphaerica Anabaena variabilis var. ellipsospora Aulosira fritschii Family: Scytonemataceae 70 Scytonema burmanicum Scytonema hofmanni Scytonema multiramosum Scytonema schmidtii Tolypothrix byssoidea Family: Rivulariaceae 75 Calothrix brevissima var. moniliforme Calothrix castellii Massal Calothrix marchica Calothrix scytonemicola ppm : parts per million

66 Results 102 Sl. Bavistin (ppm) Name of Species Control No Calothrix stellaris Rivularia. hansgirgi Gloeotrichia intermedia var. kanwaensis Gloeotrichia raciborskii Family: Mastigocladaceae 83 Mastigocladus laminosus Family: Stigonemataceae 84 Stigonema lavardei Total ppm : parts per million Fig. 14: Tolerant algal species in different concentration of Bavistin

67 Results 103 Table 17: Survival percentage of algal species in different concentrations of Bavistin with their respective algaecide value Concentration No. of Survival of Bavistin survival percentage (ppm) specie Mean of Survival percentage No. of Algaecide eliminated value specie Mean Algaecide value C.3: Effect of Malathion on Blue Green Algae It was observed that under the influence of 50 ppm, 100 ppm, 200 ppm, 400 ppm, 600 ppm and 800 ppm Malathion concentration, a reduced number of blue green algae species were found to appear in the laboratory experiment. The tolerance percntage of blue green algae species ranged 63.1%, 50.0%, 34.52%, 25.0%, 9.52% and 2.38% respectively in the above 50 ppm to 800 ppm Malathion concentrations in the laboratory. The average survival of blue green algae species confined to 30.75% only. The mean algaecide value of Malathion was found Under the influence of 50 ppm Malathion solution, 16 members of out of 26 in Chroococcaceae (61.54%) were found as tolerant species in the family as compared to control. In this concentration 19 species out of 28 in family Oscillatoriaceae (67.85%), 8 species out of 14 in Nostocaceae (57.14%), 3 of 5 species in Scytonemataceae (60.0%), 5 of 8 species in Rivulariaceae (62.5%) and one each of Dermocarpaceae and Stigonemataceae found to grow in the laboratory and found as tolerat in the above concentration. On the other hand, 10 species of Chroococcaceae, 9 of Oscillatoriaceae, 6 of Nostocaceae, 2 each of Scytonemataceae and Rivulariaceae were very sensitive to Malathion that failed to survive even 50 ppm Malathion solution. At 50 ppm the algaecide value of Malathion was calculated as As the Malathion concentration increased, the more algae species found to disappear in the experiment. In 100 ppm Malathion

68 Results 104 solution, 14 species (53.85%) of Chroococcaceae, 17 species in Oscillatoriaceae (60.71%), 2 species in Scytonemataceae 40%, in Rivulariaceae 25% and members of Dermocarpaceae and Stigonemataceae found as tolerant. A total 42 species was eliminated in 100ppm Malathion solution with algaecide value 50. In 200 ppm of Malathion, 9 species of Chroococcaceae (34.6%), and 13 species of Oscillatoriaceae (46.42%), 2 species- Nostoc linckia and Anabaena doliolum in Nostocaceae were found resistant to 200 ppm Malathion solution. Algacide value of 200 ppm Malathion was found as The members like Microcystis aeruginosa, Chroococcus minor, Gloeocapsa magma, Gloeocapsa stegophila,, Synechocystis pevalekii, Arthrospira spirulinoides, Oscillatoria acuta, Oscillatoria curviceps, Lyngbya mesotricha, Nostoc linckia, Calothrix marchica were found tolerant to 400 ppm Malathion solution. Algaecide value of 400 ppm Malathion was calculated as 75. At 600 ppm 8 species 9.52% of the control experiment were found as tolerant, they were Oscillatoria acuta, Oscillatoria princeps var. pseudolimosa, Lyngbya aestuarii, Lyngbya limnetica, Lyngbya mesotricha, Nostoc muascorum, and Calothrix marchica.the algaecide value of 600 ppm of Malathion was found Only two species, Oscillatoria acuta and Lyngbya limnetica (2.38%) out of total 84 were found tolerant to 800 ppm Malathion pesticide in laboratory condition. In average 30.75% of the blue green algae species were tolerant. The mean algaecide value of Malathion was found to be (Tables 18, 19, Fig. 15). Table -18:Tolerant blue green algal species in different concentrations of Malathion Sl. No. Name of Species Control Malathion (ppm) Family Chroococcaceae 1 Microcystis aeruginosa Microcystis flos-aquae Chroococcus cohaerens Chroococcus indicus Chroococcus macrococcus Chroococcus minor Chroococcus montanus forma ppm : parts per million

69 Results 105 Sl. No. Name of Species Control Malathion (ppm) Chroococcus montanus var. hyalinus Chroococcus pallidus Chroococcus turgidus Gloeocapsa atrata Gloeocapsa. Decorticans Gloeocapsa magma Gloeocapsa nigrescens Gloeocapsa. polydermatica Gloeocapsa. sanguinea Gloeocapsa stegophila var. crassa Gloeothece rupestris Gloeothece samoensis var. major Aphanocapsa banaresensis Aphanocapsa biformis Aphanocapsa pulchra Aphanothece pallida Aphanothece stagnina Synechocystis pevalekii Merismopedia tenuissima Family: Dermocarpaceae 27 Stichosiphon sansibaricus Family: Oscillatoriaceae 28 Arthrospira spirulinoides Spirulina gigantea Spirulina princeps Oscillatoria acuta Oscillatoria chalybea var. insularis Oscillatoria chlorina Oscillatoria curviceps Oscillatoria limosa ppm : parts per million

70 Results 106 Sl. No. Name of Species Control Malathion (ppm) Oscillatoria okeni Oscillatoria perornata Oscillatoria princeps Oscillatoria princeps var. pseudolimosa Oscillatoria raoi Oscillatoria salina Oscillatoria tenuis Oscillatoria vizagapatensis Phormidium corium Phormidium fragile Phormidium retzii Phormidium valderianum Lyngbya aestuarii Lyngbya limnetica Lyngbya major Lyngbya majuscula Lyngbya mesotricha Lyngbya porphyrosiphonis Lyngbya truncicola Symploca muscorum Family: Nostocaceae 56 Cylindrospermum indicum Nostoc ellipsosporum Nostoc linckia Nostoc muscorum Nostoc punctiforme Nostoc spongiaeforme Anabaena anomala Anabaena doliolum Anabaena fertilissima Anabaena iyengarii var. tenuis Anabaena oryzae Anabaena sphaerica ppm : parts per million

71 Results 107 Sl. No. Name of Species Control Malathion (ppm) Anabaena variabilis var. ellipsospora Aulosira fritschii Family: Scytonemataceae 70 Scytonema burmanicum Scytonema hofmanni Scytonema multiramosum Scytonema schmidtii Tolypothrix byssoidea Family: Rivulariaceae 75 Calothrix brevissima var. moniliforme Calothrix castellii Calothrix marchica Calothrix scytonemicola Calothrix stellaris Rivularia hansgirgi Gloeotrichia intermedia var. kanwaensis Gloeotrichia raciborskii Family: Mastigocladaceae 83 Mastigocladus laminosus Family: Stigonemataceae 84 Stigonema lavardei Total ppm : parts per million

72 Results 108 Fig. 15: Tolerant algal species in different concentrations of Malathion Table 19: Survival % of algal species in different concentrations of Malathion with their respective algaecide value Malathion in ppm No. of survival species Survival percentage Mean of survival percentage No. of eliminated species Algaecide value Mean Algaecide value C. 4: Effect of Cypermethrin on Blue green Algae The effect of Cypermethrin, on the existence of blue breen algae was tested in 6 different ppm concentrations under laboratory condition. In control experiment 84 species of blue green algae were found to grow. It was noted that when