Advances in Biology & BioMedicine

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1 Year: 2014; Volume: 1; Issue: 1 rticle ID: BIO14 03; Pages: 1-12 dvances in Biology & Bioedicine Research rticle Seasonal growth, Reproduction, Spore Germination and Oospore shedding in Sargassum ilicifolium (Turner) C.g. of Visakhapatnam coast, ndhra Pradesh, India D.ppa Rao 1, G. Subbarangaiah 2 & S. B. Padal 2 1 Dept. of Botany, Government Degree College, Chodavaram, Visakhapatnam , ndhra Pradesh, India. 2 Dept. of Botany, ndhra University, Visakhapatnam , ndhra Pradesh, India. Correspondence should be addressed to S. B. Padal Received 08 September 2014; ccepted 12 September 2014; Published 21 October 2014 Copyright: 2014 S. B. Padal et al. This is an open access article distributed under the Creative Commons ttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. bstract Population of Sargassum ilicifolium(turner) C.g. was observed throughout the year in the two areas studied i.e., in and around Visakhapatnam coast. Young and erect fronds are developed from the perennial holdfast in the month of arch/pril. Rapid increase in the mean length of erect fronds was observed from ay onwards and they attain maximum size in November/December and January. Fertile fronds were found for a short duration in a year i.e., from October onwards at Gangavaram and Pudimadaka. The percentage of fruiting plants varied during the fruiting season and maximum number of fertile plants were found in the month of December/January. The liberation of oospores was observed from the first day onwards and increased from day two with peak output on day four and no liberation of oospores was observed after sixteenth day. The maximum shedding of oospores was seen during December/January every year coinciding with the peak growth. The germination rate of oospores was also higher in December/January than in other months of the year. Key Words: Seasonal growth, Reproduction, Spore Germination, Oospore shedding, Sargassum ilicifolium, Visakhapatnam coast, ndhra Pradesh. Introduction The species of Sargassum are abundant among the brown algae occurring along the Indian shores and these are the chief sources for the extraction of alginic acids in the country (Umamaheswara Rao, 1970). ore than 90 species of Sargassum have been reported from Indian shores (Srinivasan, 1966). From Visakhapatnam 4 species of Sargassum viz.,s.ilicifolium, S.polycystum, S.tenerrimum and S.vulgare were reported (Umamaheswara Rao and Sreeramulu,1970). The above four species have also been found in other localities along the coast of Visakhapatnam.

2 Sargassum species and other brown algae of the tropical shores are less investigated when compared with ecological, biological and biochemical aspects studied on the members of Laminariales and Fucales of temperate shores. Sargassum muticum species introduced from Japan has received much attention in recent years and many aspects relating to its distribution, growth and development, fruiting behaviour, dispersal and colonization have been studied in details by Fletcher and Fletcher (1975); Norton (1977a,b, 1980 and 1981); Fletcher (1980); and Chritchlez (1980). In other geographical areas also ecological and other investigations on the species of Sargassum were made in recent years by Yoshida (1960); Yoshida et al.,(1963), Umezaki (1974), Tanuguchi and Yamada (1978) have worked on Sargassum species of Japan and De Wreede (1976) and Prince and O`Neal (1979) on Sargassums of Hawaii and merica respectively. In view of the importance of brown algae as a source of algin and as food, fodder and fertilizer, special efforts were made in India since 1950 to study the chemical composition and algin content of brown weeds by many workers. Later on, studies were made on the seasonal changes on the extraction of alginic acid contents and on the life cycles of different species of Sargassum (Umamaheswara Rao, 1969; Chauhan and Krishnamurthy, 1971; Raju and Venugopal, 1971; Umamaheswara Rao and Kaliaperumal,1976) growing along the Gujarat, Goa and andapam shores. t Visakhapatnam some preliminary observation were made on the seasonal changes in the abundance of brown algae in a general ecological study of the intertidal algae (Umamaheswara Rao and Sreeramulu, 1964; Umamaheswara Rao, 1990). t present, detailed ecological studies on S.ilicifolium occurring in two localities viz. Gangavaram and Pudimadaka along the Visakhapatnam coast was made for a period of two and half years from Decemer 1995 to ay 1998 is presented in this paper. Fig.1. Coast line showing different study sites viz. Gangavaram, Pudimadaka 2

3 1995 D 1996 J F J J S O N D 1997 J F J J S O N D 1998 J F ean Length ( Cm ) aterials and ethods Results Data on the seasonal groth of Sargassum ilicifolium (Turner) C.g. was collected from December 1995 to ay 1998, following the method given by Umamaheswara Rao (1969) for S.wightii. Thirty plants of Sargassum ilicifolium (Turner) C.g., were randomly selected from the samples collected from the two field stations viz., Gangavaram and Pudimadaka(Fig.1) (near Visakhapatnam) and the mean length of the main shoots and also the lateral branches from the basal holdfast or stem like portion were measured at fortnight intervals. From the data obtained, mean height of the plants or shoots were calculated for each month to show the variation in the growth in different months of the year. While taking the length of the plants, observations were made on their fruiting condition to know the reproductive periods and to estimate the frequency of the plants bearing receptacles in the populations. Spore shedding experiments were carried out under the laboratory conditions to study the changes in the liberation of oospores in different months of the year. Sargassum ilicifolium (Turner) C.g. Data collected for a period of two and half years from December 1995 to ay 1998 on the seasonal growth behaviour in the populations of Sargassum ilicifolium (Turner) C.g. is shown in Fig.2 populations of Sargassum ilicifolium (Turner) C.g. was found throughout the year in the two areas selected, viz., Gangavaram and Pudimadaka. Young and erect fronds developed from the perennial holdfasts in the months of arch and pril and some degenerating fronds of previous generation with receptacles were also observed during this period. Rapid increase in the mean length of the erect fronds was observed from ay onwards in the four localities studied (Fig.2) and many of the erect fronds attained maximum size in November/December and January. The same type of growth curve was observed from the two localities but the mean length of the fronds varied slightly due to habitat variations. Plants of sheltered habitat at Pudimadaka were taller than those of in more exposed habitat at Gangavaram. The appearance and bushyness of the plants also varied in sheltered and exposed habitats. The standard error plotted in Fig.2 also suggests that variations within the monthly samples were minimum Gangavaram Pudimadaka onth Fig.2. Seasonal growth changes in Sargassum ilicifolium (Turner) C.g.

4 19 D 19 F J O N D 19 F O N D 19 F Fruiting Plants % The abundance of fruiting plants observed in the two sites from December 1995 to ay 1998 is shown in Fig. 3. The fertile plants were found for a short duration in a year. The fruiting period was extended for 6 to 9 months from October to June with slight variations from one site to the other in different years of this study(fig.3). The fertile plants were observed from October onwards at Gangavaram and Pudimadaka in Sargassum ilicifolium (Turner) C.g Gangavaram Pudimadaka 0 onths The percentage of fruiting plants varied during fruiting season and maximum number of fertile plants. (100%) were found in the month of December/January. Number of receptacles per plant estimated is given in table,1. During the three fruiting periods, the number Fig. 3. Seasonal changes in the percentage of fruiting plants of receptacles per plant ranged from 24 to 254 at Gangavaram, 9 to 218 at Pudimadaka. inimum number of receptacles were found at the beginning and at the end of the fruiting seasons and maximum number in the months of December/January. Table No.1 Sargassum ilicifolium (Turner) C.g. onth & Year No. Of Receptacles per plant Collected at Gangavaram Collected at Pudimadaka Dec Jan Feb ar Nov ** 28 Dec Jan Feb Dec * 154 Jan * Feb ar ** Highest* Lowest**

5 Oospores / Plant / Day In order to show the trends in the daily liberation of spores from the receptacles, under laboratory conditions, data obtained continuously for 16 days are plotted in Fig.4. s depicted in Fig.4, the liberation of oospores was seen from first day onwards. The daily output of oospores increased from day two onwards with peak output on day five. From day sixth onwards the oospores output decreased and it was minimum between day ten and day sixteen in the experiments carried out in the laboratory. Shedding of oospores from the receptacles was not observed after sixteenth day. In general, the output of oospores was relatively higher in the first week than in the second week in the experiments conducted in the laboratory. The oospores enveloped in the mucilaginous oogonial membrane, are first attached to the receptacles soon after their release and they are discharged into the petri-dish in different stages of germination Sargassum ilicifolium (Turner) C.g No. of Days Fig.4. Daily liberation of oospore output Data collected for three fruiting seasons between December 1995 and ay 1998 on the shedding of oospores (based on the means of 1st and 2nd week) is given in table 2, to show the seasonal changes in the oospore producing capacities. The oospore output ranged from 36,576 to 3,937 at Gangavaram and 3,099 to 534 at Pudimadaka oospores per plant in first and second week respectively. The oospores liberated in the second week were not as healthy as those liberated in the first week of the experiments. Fig 5, shows the seasonal changes in oospore output. The maximum shedding of oospores was seen during December/January every year coinciding with the peak growth (Fig 2). The estimated number was more in than in the year and

6 Table No. 2 (Spore output per plant) Sargassum ilicifolium (Turner) C.g. onth & Year Spore output per plant Collected at Gangavaram Collected at Pudimadaka I Week II Week I Week II Week Dec , Jan , , Feb ** * Nov ** Dec , , Jan , , Feb ** 0 Dec ,576* 3,937* 4,081 1,617 Jan ,813 2,847 18,312* 19,729* Feb , , ar Highest* Lowest** The relative abundance of germinating oospores was presented in table 3. The germination rate was higher in December or January than in the other months of fruiting season. In the first week of the experiments the percentage of germination of oospores collected at Gangavaram ranged from39 to 82% and the plants collected at Pudimadaka ranged from 52-90%. Table No.3 (% of germination) Sargassum ilicifolium (Turner) C.g. onth & Year % of Germination Collected at Gangavaram Collected at Pudimadaka I Week II Week I Week II Week Dec Jan Feb Nov * Dec * Jan ** Feb ** 0 Dec * 59.3 Jan * Feb ** ar Highest* Lowest** Discussion and Conclusion Some details on seasonal aspects of growth behaviour of some species of Sargassum are available in publications of Dawson( 1941), Richard( 1984), Srinivasan( 1946) and Umamaheswara Rao and Sreeramulu( 1964) and detailed ecological studies on the species of 6 Sargassum occurring in different geographical areas were made in recent years (Tsuda, 1971; De Wreede, 1976; Prince and O'Neal 1979;TanuguchiandYamada, 1978; Umezaki,1974; 1983;1984 and 1986;Dawes, 1987; FIetcher and Fletcher 1975; Richard, 1984; Nunez et al., 1996).

7 Because of the economic importance, especially as an algin yielding alga, ecological studies, particularly on the growth and fruiting cycles were undertaken on some species of Sargassum (Umamaheswara Rao 1969; Raju and Venugopal, 1971; Chauhan and Krishnamurthy, 1971; Chennubhotla et al., 1982). In many species of Sargassum investigated so far, erect shoots developed from the perennial basal parts or holdfasts, grew rapidly in different months and maximum increase in length of the erect shoots was found either in summer, late summer or winter months with a unimodel growth cycle. In S.patens (Tanuguchi and Yamada, 1978), S.miyabei (Umezaki, 1974), S.duplicatum (Tsuda,1971), S.filipendula and S.pteropleuron (Dawes, 1987), plants attained their maximum height between pril and June each year and in S.muticum (Fletcher and FIetcher, 1975) in June and July months. Umezaki (1974, 1983,1984) reported peak development of plants during the months of July or ugust. Species of S. ringgoldianum (Umezaki, 1986) and S.obtusifolinm (De Wreede, 1976) attained their maximum size in the month of September. Species like S.pteropleuron (Prince and O'Neal, 1979) attained maximum growth between October and December and S.polycystum (Tsuda, 1971) in February. In India, species of Sargassum such as S.wightii (Umamaheswara Rao,1969) S.plagiophyllum (Raju and Venugopal, 1971) and S.swartzii (Chauhan and Krishnamurthy, 1971) reached their maximum height between October and December / January. Whereas S.ilicifolium and S.myriocystum (Chennubhotla et al, 1982) plants grew to maximum size between December and February. However, regular seasonality in growth was not reported by De Wreede (1976) in S.oligocystum. In the present study at two places nearby Vi.saktiapalnam, plants of Sargassum ilicifolium (Turner) C.g. initiated its growth from arch to pril and attained maximum heights in the months of November, December/ January, every year with rapid increase in growth from June or July, Defoliation of erect shoots was seen in January/February. Similar growth cycle was observed in Sargassum ilicifolium (Turner) C.g. studied at Gangavaram and Pudimadaka. These observations on Sargassum ilicifolium (Turner) C.g. is in agreement with the annual growth behaviour reported for S.vulgare and S.polycystum of the Visakhapatnam and nearby places (ppa Rao,1998). nd all these observations on S.ilicifolium, S.vulgare, and S.polycystum are also in agreement with the annual growth behaviour for other Indian species such as S.wightii (Umamaheswara Rao, 1969), S.swartzii (Chauhan and Krishnamurthy, 1971).In S.ilicifolium, studied on the South East coast of India (Chennubhotla, et al 1982), peak growth was observed upto February unlike in the present study. Similar variations in the periods of maximum development of plants were reported in the species growing in the warmer and colder parts of the Japan( Yoshida, 1960;Umezaki, 1974; 1984 and 1986;Tanuguchi and Yamada, 1978) and other areas for S.polycystum and S.pteropleuron (Tsuda, and Prince and O'Neal, 1979). In the present study on S.ilicifolium, showed only one peak period of growth i.e., during December / January every year, coinciding with the other two species of Visakhapatnam and nearby places. Viz., S.vulgare and S.polycystum (ppa Rao, 1998); S.polycystum ( Srinivasa Rao, 2002). Whereas in some red algae studied by SubbaRangaiah and Umamaheswara Rao, (1983); Sudhakar(l992); Sudhakar and SubbaRangaiah( 1993); Vanilla kumari and SubbaRangaiah (1997); Vanilla kumari (1998) on the same coast, showed two peak periods of growth i.e., one in December/ January and the other in June/July every year. The present study agrees with the statement of Richard (1984), wherein, he reported that the species of Sargassum shows maximum growth during colder months of the year in tropical and sub tropical regions and during summer in temperate regions. Fruiting plants of Sargassum were found for one to five months duration by many workers, during its maximum growth season. In S.oligocystum, S.obtusifolium(De Wreede, 1976);S.patens and S.serratifolium (Tanuguchi and Yamada,1978), 7

8 S.hornerii and S.muticum (Okuda, 1980), S.ringgoldianum (Umezaki 1986). Plants with receptaclcs were found in the periods from arch to ay. In S.thunbergi, S.ringoldianum (Yoshida,1960; Umezaki, 1974), fruiting plants were reported between June and October months. In other species like S.polyphyllum (DeWreede,1976) S.pteropleuron (Prince and 0'Neal,l979); S.folipendula (Dawes,1987), S.wightii (UmamaheswaraRao,1969) S.swartzii (Chauhan and Krishnamurthy, 1971; urthy et.al.,1978) and S.plagiophyllnm (Raju and Venugopal, 1971) fertile plants occurred between October and January/February. In S.vulgare studied at Jodugullapalem and nearby places, (ppa Rao, 1998) fruiting plants were observed for 6-7 months from October to pril/ay with maximum number of plants with receptacles (100%) in the months of December or January, which coincides with S. vulgare of the present study. From arch onwards, the receptacles were not healthy, though they were present till pril/ay. In S.polycystum, fertile plants were seen for 3-4months between November and February every year at Visakhapatnam (ppa Rao1998). The fruiting cycle of Visakhapatnam and other nearby places of the present study agrees with that of the other species of Sargassum reported from India (Umamaheshwar Rao, 1969;Chauhan and Krishnamurthy 1971; urthy et.al., 1978; Raju and Venugopal, 1971) and other geographical areas(de Wreede, 1976; Prince and O'Neal, 1979 and Dawes,1987). Detailed studies were not made on the oospores producing capacity of Sargassum species, though some information on the formation and liberation of oospores is available. For instance, many workers (Yoshida, I960; FIetcher and FIetcher, 1975; De Wreede, 1976; Tanuguchi and Yamada 1 978; Prince and O'NeaI, 1979), just reported the periods of peak liberation of oospores from the fertile plants, without giving any quantitative data. From India, Chauhan and Krishnamurthy, (1971) found that oospore output in S.swartzii was more than 50,000 per plant. These workers observed peak liberation of oospores in S.swartzii in December every year. Umamaheswara Rao and Kaliaperumal (1976) estimated the oospore producing capacity of S. wightii growing at andapam on the south east coast of India for 2 fruiting seasons from October to February. The number of receptacles per plant varied from 608 to747 in December. The output of oospores per plant ranged from 117,000 to 370,000 in this species. In the present study, data was collected for 2 1/2 years on the oospore producing capacity of S.ilicifolium growing in two localities of Visakhapatnam coast. In the laboratory experiments, oospores were liberated from receptacles in large numbers, nearly for one week with 88 to 99% germination rate and the oospore output decreased in the second week from receptacles Number of receptacles and oospore output per plant varied during the fruiting cycle with maximum number of receptacles per plant and shedding of oospores in the months of December or January every year. During, this period of maximum shedding (December / January), the oospore output in S.ilicifolium ranged from 3,633 to 40,513 per plant and it was very high in S.vulgare, where it ranged from 29,220 to 3,05,983 oospores /plant (ppa Rao, 1998). The oospore production also varied from one locality to another in the present study (Table II) and also in S.vulgare (ppa Rao, 1998). The present observations on the period of maximum shedding of spores agree with the earlier findings on S.wightii (Umamaheswara Rao and Kaliaperumal, 1976) and S.swartzii (Chauhan and Krishnamurthy, 1971). But of course, a common procedure should be adopted, to estimate the number of reproductive elements that are released from the plant. In the present study on the liberation of oospores in S.ilicifolium, maximum shedding was observed on day three and day five as in S. vulgare (pparao, 1998). Norton (1981) reportd the liberation of eggs at interval of several days and also at about 7 days interval in S.muticum and at intervals of 13 days (Deyshig and Norton, 1982). S.horneri liberated eggs at intervals of 2 to 8 days (Okuda 1981) and Oza and Krishnamurthy (1968) on the release of carpospores of Gracilaria verrucosa, ohan Joseph 8

9 and Krishnamurthy (1977) on Gracilaria corticata, on the second or third day. aximum number of spares were liberated on day one in the studies made at Visakhapatnam on different species, for example in Gracilaria corticata, G.textorii, Gracilariopsis sjoestedtii (Subba Rangaiah and Umamaheswara Rao, 1983), Gelidiales (Kaliaperumal, 1979), Cryptonemiales (Vanillakumari, 1998) Ceramiales (Sudhakar, 1992) and also in Fucus serratus at Isle of an (Subba Rangaiah, 2002). Even though much emphasis was not given on the germination and survival of oospores due to some difficulties encountered in the experimental work, the data obtained show that the germination rate in oospores of S.ilicifolium did not very much in different months of the year which coincides with S.vulgare (ppa Rao, 1998).The percentage of germ mating oospores varies from 64 to 90% in all the months of their occurrence in the field. Though the literature related is scanty, it indicates that the spore germination varies in different months of the year. In Gracilaria corticata, Hypnea valentiae (Subba Rangaiah, 1983 b; 1984 b) Wrangelia argus and Centroceros clavulatum (Sudhakar, 1992), mphiroa fragilissima and Grateloupia lithophila (Vanilla kumari, 1998) also, the highest percentage of dividing tetraspores and carpospores was observed during the peak period of shedding. In Gelidium robustum, though fruiting plants were observed through out the year spore germination was observed during the spring and early summer (Barilotti and Silverthrome, 1972). Similarly Prince and Kingsbury (1973) reported seasonal variation in the growth of germlings of Chondrus crispus. In Gelidium pusillum and Pterocladia heteroplatos also, the highest number of dividing spores was observed during and after peak period and the rate of germination was low in Pterocladia heteroplatos than Gelidum pusillum and germination was not observed in Gelidiopsis variabilis within 24 hours. (Kaliaperumal, 1979). Wrangelia argus. Centroceros clavatum (Sudhakar 1992) mphiroa fragilissima and Grateloupia lithophila (Vanilla Kumari, 1998), exhibited a high rate of gennination of 90%, compared to Gigartinales (60%) (Subba Rangaiah, 1983 b,1984 b) and Gelidiales (40%) (Kaliaperumal, 1979). In the present study, on S.ilicifolium, it shows nearly about 82% of germlings in the first week (Table.3), which coincides with S.vulgare (ppa Rao, 1998). But where as in Fucus se rratus, 100% germination of oospores was observed at Isle of an (Subba Rangaiah, unpublished). Though the observations are preliminary, but it suggests that all the spores liberated throughout the year may not germinate within 24 hrs and their Viability is high in certain periods or during or immediately after peak growth periods. But the viable and germinating oospores are evident in all the months (4 to 5 months ) of its occurrence in the field and as it was also observed by ppa Rao ( 1998) in S.vulgare, shigeni, (1976) in Hypnea valentae and Subba Rangaiah (1983 b, 1984 b) in Gracilaria corticata and Hypnea valentiae, Sudhakar (1992) in Wrangelia argus and Centroceros clavulatum, Vanillakumari (1998) in mphiroa fragilissima and Grateloupia lithophila. The above workers had calculated the percentage of germinating spores on day one or day two. But in the present study, the percentage germination of oospores has been calculated from the oospores liberated for nearly two weeks. However, more detailed studies are needed and the experiments should be conducted for more number of days to see the percentage germination in different months of the year up to a considerable growth of the germlings. From the results obtained in the present study, it was observed that the maximum growth of the plants, maximum fertile plants, maximum oospore shedding and also maximum germinating oospores was found during the months of December/ January. Therefore, it is advised to harvest the plants of S.ilicifolium in the field in the month of February, so that the natural populations can be maintained in the field without causing hindrance to the oospore shedding etc. nd it is also advised that the harvesting of the plants can be done by cutting the plants just above the holdfast region, keeping in view that young and erect fronds are developed from the perennial holdfast in the month 9

10 of arch/pril, so as to maintain the natural populations for the next generation. References 1. ppa Rao Studies on the ecology of some species of Sargassum (Fucales, Phaeophyceae) along the Visakhapatnam coast. India. Ph.D thesis submitted to ndhra University, Visakhapatnam. 2. Barilotti, D.C. & W. Silver Thome resource management study of Gelidium robustum. Proc. Seventh. Int. Seaweed symp Chauhan, V. D. & V.Krishnamurthy Ecology and seasonal succession of Sargassum swartzn(tum.) C.g.in Indian waters. Phykos. 10: Chennubhotla, V. S. K, N. Kaliapemmal,S.KaIimuthu,.Selvaraj, J.R.Ramalingam &.Nijamuddin seasonal changes in growth and alginic acid and mannitol contents in Sargassum ilicifolium (Turner) J.g and S.myriocystum J. g. Ind. J. ar. SCL,11: Chritchley,.T The further spread of Sargassum muticum.br.phycol.j. 15: Dawes, C.J Physiological ecology of two species of Sargassum (Fucales, Phaeophyta) on the west coast of Florida. Bull.mar.SciQ(2);m Dawson, E.Y Field observation on the algae on the Gulf of California. llan Hancock Pacific expeditions 3(7): Deysher,L&T..Norton Dispersal and colonization in Sargassum muticum, J.exp.mar.Biol.Ecol.56: De wreede, R.E The Phenology of three species of Sargassum (Sargassaceae, Phaeophyta) in Hawaii. Phycologia. 15 : Fletcher, R. L Studies on the recently introduced brown alga Sargassum mulicum (Yendo) Fensholt Periodicity in gamete release and incubation of early germling stages.bot.mar.23 : FIetcher,R.L & S..FIetcher Studies on the recently introduced brown alga Sargassum muticum (Yendo) Fensholt 1. Ecology and Reproduction. Bot. ar., 18 : Kaliaperumal, N Ecological studies on some red algae of the Visakhapatnam coast, 10 Ph.D. thesis submitted to ndhra University. Waltair India. 13. ohan Joseph, & V.Krishnamurthy Studies on the shedding of carpospores in Gracilaria coticata J.g. Seaweed Res. Utiln., 2: shigeni, K. E Studies on the reproduction of selected species of Hypnea (Rhodophyta,Gigartinales) from Hawaii. Bot. ar., 19: urthy,.s.,.bhattacharya & Radia Ecological studies on the intertidal algae at Okha (India). Bol. ar., 21: Norton, T a. Ecological experiments with Sargassum muticum. J. mar. biol. ss. U.K. 57: Norton,T b. Growth and development of Sargassum muticum (Yendo) Fensholt. J. Exp. ar. Biol. Ecol., 26: Norton, T Sink. swim or stick of Sargassum muticum propagules. Br. Phycol.J., 15: Norton, T Gamete expulsion and release in Sargassum muticum. Bot. ar., 24: Nunez_Lopez Roberto urelio &.argarita Casas-Valdez Phenology of the species of Sargassum (Fucales, Sargassaceae) in three zones of Bahia Concepcion, Baja California Sur, exico, Revista de Biologia Tropical. 44 (2 part ): Okuda, T Egg liberation in some Japanese Sargassaceae (Phaeophyceae) P roc. Inter, natl. Seaweed.Symp.Geoborg Sweden. 10; Oza, R. & V.Krishnamurthy 1968 Studies on carpospore rhythm of Gracilaria verrucosa (Huds) Papenf. Bot. ar., 11(1-4): Prince, J.S & J. Kingsbury The ecology of Chondrus crispus at Plymouth assachussetts- 11 Field studies m J Bot., 60: Prince, J.S & S.W.O`Neal The ecology of Sargassum pteropleuron Grunow (Phaeophyceae, Fucales) in the waters of South Florida 1. Growth, reproduction and popu- lation structure, Phycologia, 18: Raju, P. V & R.Venugopal ppearance and growth of Sargassum plagiphyllum (ert) C.g on a fresh substratum Bot.ar., 14: Richard,. e Court Seasonal Patterns of abundance, distribution and phenology in relation to growth strategies of three Sargassum species. J. Exp. ar. Biol. Ecol. 74:

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12 51. Yashida, T On the growth rings found in the root of Sargassum Harvey (Fucales). Bull. Jap. Soc. Sci. Fisheries. 26(7): Yashida, T., T.Sawada &. Higaki 1963 Sargassum vegetation growing in the sea around Tsuyazaki, North Kyushu, Japan Pacific Sci. 17(2):