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1 Phytotaxa 244 (3): ISSN (print edition) Copyright 2016 Magnolia Press Article PHYTOTAXA ISSN (online edition) Williamsella iraqiensis sp. nov., a new diatom (Bacillariophyta, Fragilariophyceae) from Sawa Lake, South Iraq ADIL Y. AL-HANDAL 1*, J.P. KOCIOLEK 2 & D.S. ABDULLAH 1 1 Department of Marine Biology, Marine Science Center, University of Basra, Iraq 2 Museum of Natural History and Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA, * Corresponding author ( adil.alhandal@gmail.com) Abstract A new species of the genus Williamsella (Fragilariophyceae) is described from a saline lake in southern Iraq. Williamsella iraqiensis sp. nov. was found free living and as epiphyte on Chara sp. in Sawa Lake. This species is the second described of the genus Williamsella which was originally reported from Blue Lake warm springs, Utah, USA. Williamsella iraqiensis sp. nov. and W. angusta can be readily distinguished under LM by having a relatively wide sternum which results from shorter striae along valve margin. Description of valve ultrastructure and comparison with other related genera such as Fragilaria is provided. Williamsella iraqiensis is a brackish water species preferring warm waters. Introduction Identification of the genera and species belonging to Fragilariophyceae can be rather difficult with light microscopy owing to the similarities between taxa suggested at that level of optical resolution. Despite comparative studies (e.g. Lange-Bertalot & Ulrich 2014) and major revisions (Williams & Round 1986, 1987, 1988) where several genera were proposed or established, the taxonomy of the group is still in a state of flux, as the systematic position of many species has been emended or transferred (e.g. Morales 2001, 2003, Edlund et al. 2006, Garcia 2006, Hamilton & Siver 2008). Since 1987, species previously in the genus Synedra Ehrenberg (1830: 60) in particular have been reassigned to several new or previously established genera, such as Ctenophora (Grunow 1862: 385) William & Round (1986: 330), Catacombas Williams & Round (1986: 314), Hyalosynedra William & Round (1986: 316), Neosynedra William & Round (1986: 332), Tabularia (Kützing 1844: 67) Williams & Round (1986: 320), Synedropsis Hasle, Medlin & Syversten (1994: 248) and Ulnaria (Kützing 1844: 66) Compère (2001: 100). In some cases, scanning electron microscope observations are needed to accurately discriminate between allied taxa and to reveal the fine structural features that diagnose and differentiate genera. Such observations have recently added new taxa to this complex group of diatoms (Prasad & Livington 2005, Prasad et al. 2001, Morales 2005, 2006, Williams et al. 2009, Morales et al. 2010, 2012, 2013, Cejudo-Figueiras et al. 2011). Williamsella Graeff, Kociolek & Rushforth (2013: 5) is a new, monotypic genus in this group, with its lone species, W. angusta Graeff, Kociolek & Rushforth (2013: 7), described from Blue Lake warm springs, thermal springs with elevated NaCl levels. This genus is similar in some ways to Fragilara Lyngbye (1819: 182) but was separated from this genus on the basis of the lack of spines, growth habit as individual cells (not colonies) and being found in salt water. It differs from Ulnaria by its valves having a single labiate process (Ulnaria possess two labiate processes per valve). The areolae with external coverings seem to be unique for Williamsella. In the present work, a new species, Williamsella iraqiensis sp. nov. Al-Handal et Kociolek is described from Sawa lake, a salt lake in southern Iraq. The species was found on the sediment of the lake as solitary cells and also, but rarely, as epiphytes on Chara sp. which covers the lake bottom of Sawa Lake. Accepted by Saúl Blanco Lanza: 7 Jan. 2016; published: 19 Jan

2 FIGURE 1. Map of the region showing the location of Sawa lake in the South Western desert of Iraq (after Al-Handal et al. 2014). 290 Phytotaxa 244 (3) 2016 Magnolia Press AL-HANDAL ET AL.

3 Material and methods Sawa Lake (Fig. 1) is a closed lake located in the southern desert of Iraq (31º 18 N, 45º 00 E) with a total surface area of ca 10 km 2. Depth of the lake ranges from 0.5 m at the coast to 5 m at the middle. There are no tributaries into the lake but it receives water from an underground spring at its center. Owing to excessive evaporation associated with high temperatures, particularly in the warm periods of the year (May to October), the salinity of the lake ranges between 30 and 35 psu. Lake water contains high concentrations of sulfur (CaSO 4 ) which comes from the underlying rocks. The smell of sulfur is evident all around the lake. The bottom of the lake is covered with patches of the macrophyte Chara sp., particularly in the shallow parts. The lake s center is rather deep where water flows via springs (for detailed description of the site see Al-Handal et al. 2014). Samples were collected by scraping the uppermost layer of sediment and kept in plastic bottles, to which a few drops of formalin were added for preservation. Shoots of the macrophyte Chara sp. were cut by hand and preserved in plastic containers. In the laboratory, sediment samples were shaken and left to settle for few minutes, the supernatant was then washed with deionized water to remove salts, and diatoms were cleaned by boiling with concentrated hydrogen peroxide. Chara shoots were shaken vigorously to free diatom frustules, and were cleaned as above. Cleaned diatoms were placed on a cover slip and left to dry at room temperature and mounted in Naphrax. LM examination and imaging were made using a Zeiss Axioimager A2 microscope (LM, Carl Zeiss AB) with differential interference contrast objectives. SEM images were taken using Hitachi S-4500 SEM operated at 15 kv (University of South Florida, USA). Results Division Bacillariophyta Class Fragilariophyceae Order Fragilariales Family Fragilariaceae Genus Williamsella Williamsella iraqiensis Al-Handal et Kociolek, sp. nov. (LM Figs 2 7, SEM Figs 8 21) Cells solitary with four plate-like plastids distributed in the middle third of the valve (Fig. 7). Valves linear, narrow, with slightly flattened rounded apices (Figs 8, 9, 12, 22), µm long, 2 3 µm wide at the center and µm at the apices (n = 50). External valve face flat. Sternum distinct in the middle but becoming very narrow towards the apices (Figs 8, 12, 18). Sternum is wider on the internal side of the valve and not narrowing near the apices (Figs 9, 10, 11). Striae uniseriate, opposite, parallel, in 10 µm, composed of 4 6 areolae in the middle and 2 3 areolae near the apices (Fig. 8). Striae do not reach valve margins externally. Areolae round and poroid. Areolae are covered with a velum (Fig. 13). An apical pore field is present on each apex, lying in a very shallow ocellimbus and composed of three rows (rarely four) of porelli, 5 8 in each row (Figs 13, 14, 17). Rimoportula single, located transapically at the central axis of the valve at a distance of two straie from valve apex, externally as a rectangular opening (very rarely oblique) and as a slit surrounded by convex, dome-like labiate processes internally (Figs 10, 12, 16). Cingulum composed of one band with fine pores, in 10 µm (Figs 19, 20, 21). Type: IRAQ. Sawa Lake, 31º 18 N, 45º 00 E, 2 m a.s.l., Al-Handal, 13 May 2013 (holotype: BM!, individual on slide 101/809, deposited in the Natural History Museum, London, UK, here illustrated as Fig. 2. Isotype: slide no. SL52020, Department of Marine Biology, Marine Science Center, Basra, Iraq). Etymology: The epithet iraqiensis refers to the geographic location where this second Williamsella species was found. Differential diagnosis: Williamsella iraqiensis is similar to W. angusta but can be readily distinguished from it under LM by the relatively wide sternum which results from shorter striae along valve margin. In the later species the axial area is very narrow and linear. Transapical striae are denser in W. iraqiensis as compared to W. angusta (24 30 in 10 µm versus in 10 µm, respectively). Areola number in each stria is much lower in W. iraqiensis than in W. angusta. The apical pore field in both species appears similar in the shape of the pores but their number is different. It is wider in W. iraqiensis and is not located deep inside the ocellimbus as in W. angusta. Shape and structure of the copulae look also similar. a new diatom from Iraq Phytotaxa 244 (3) 2016 Magnolia Press 291

FIGURES 2 7. LM images of W. iraqiensis showing variation in valve outline and arrangement of striae. 7. Shape and distribution of chromatophores. Under light microscope, W.

4 FIGURES 2 7. LM images of W. iraqiensis showing variation in valve outline and arrangement of striae. 7. Shape and distribution of chromatophores. Under light microscope, W. iraqiensis may look similar to some taxa belonging to Fragilaria, particularly in valve outline and striae organization. Examination of live material of this species showed absence of any colonial mode of life, a criterion that is currently accepted for recognizing the species of Fragilaria (Round et al. 1990). SEM images of many specimens did not show any spines or other structures to support chains or other colonial forms. Williamsella, in general, shares morphological similarities under LM such as valve outline and striation pattern with several other genera, such as Tabularia, Ulnaria or Synedropsis. However, large differences in ultrastructure between Williamsella and these genera can be seen under SEM; including the fine structure and arrangement of striae, the apical pore field and the structure and position of the ocellimbus, the number and shape of the rimoportula, and the number and structure of the cingulum bands. In their description of Williamsella, Graeff et al. (2013) detailed some ultrastructural features which set this genus apart from other allied general. Most important in distinguishing this genus 292 Phytotaxa 244 (3) 2016 Magnolia Press AL-HANDAL ET AL.

from those listed here is the external occlusions on the areolae, a feature absent in these other taxa. Table 1 summarizes the main characteristics of these genera in comparison to Williamsella.

5 from those listed here is the external occlusions on the areolae, a feature absent in these other taxa. Table 1 summarizes the main characteristics of these genera in comparison to Williamsella. FIGURES SEM micrographs of W. iraqiensis. 8. External view of whole valve. 9. Internal view of the valve. 10. Internal view of the rimoportula showing its structure and position. 11. Internal view of the valve showing valve curvature and arrangement of areolae. 12. External side of the upper third of the valve showing a rimoportula, arrangement of areolae and the flat nature of the valve. 13. Valve apex showing the structure of the apical pore field, and areolae covered with vela. 14. Internal view of valve apex showing a rimoportula and the apical pore field. Ecology: Williamsella iraqiensis was common on the sediment of Sawa Lake, Iraq. Salinity of the lake water during sampling was 34 psu indicating highly saline conditions of an inland water impoundment. In addition to high salinity, the lake water is characterized by high concentrations of gypsum (CaSO 4 ) which almost reached saturation a new diatom from Iraq Phytotaxa 244 (3) 2016 Magnolia Press 293

levels (6952 ppm, Al-Handal et al. 2014). Some healthy frustules of W. iraqiensis were also found as epiphytes on Chara sp., a submerged macrophyte widely distributed in the lake. FIGURES 15 22.

6 levels (6952 ppm, Al-Handal et al. 2014). Some healthy frustules of W. iraqiensis were also found as epiphytes on Chara sp., a submerged macrophyte widely distributed in the lake. FIGURES SEM micrographs of W. iraqiensis. 15. Valve apex without rimoportula. 16. Valve apex with rimoportula and the shallow ocellimbus. 17. Valve apex with four rows of areolae in the apical pore field. 18. Middle of the valve showing arrangement of areoale. 19. Cingular band with a single row of areolae. 20, 21. Shape of the cingular band. 22. Whole view of the valve in low magnification. Acknowledgments The authors wish to thank the Marine Science Centre, Basra for providing field and laboratory equipment. Thanks are also due to Mr. Tony Greco, University of South Florida (USF), USA, for his help in SEM. The first author is grateful to Prof. H. Lange Bertalot, Goethe Universität Frankfurt for his useful comments on the images, and to Dr. A.K.S.K. Prasad, Florida State University, USA for valuable discussion on the Fragiliariales. Gratitude is also due to Prof. J. Dixon and Prof. C. Hu of the Faculty of Marine Science, University of South Florida for their invitation to visit and use the faculty facilities to accomplish this work. The authors thank anonymous reviewers for improving the article and the editor of Phytotaxa for valuable comments. 294 Phytotaxa 244 (3) 2016 Magnolia Press AL-HANDAL ET AL.

7 TABLE 1. Comparison between Williamsella and other similar genera. Feature Williamsella Ulnaria Tabularia Fragilaria Synedropsis Plastids four plate-like in the middle of the valve two plate-like two plate-like two plate-like two plate-like Valve outline valves linear narrow with flattened rounded apices valves linear to linear lanceolate, valves mostly narrowed near the apices valves elongated, linear to lanceolate with rounded, rostrate to capitate apices valves linear to linear-lanceolate (occasionally elliptical) with rounded, rostrate or capitate apices. Valve center becomes swollen in some species valves narrowly elliptical lanceolate with rostrate apices Striae structure striae uniseriate, opposite, parallel, poroid areolae, areolae covered with velum striae opposite, unisteriate to biseriate, areolae simple, not covered with velum striae biseriate, complex structure in areolae, cribrate, not covered with velum striae arrangement is widely variable among species, areolae not covered striae uniseriate with circular, poroid areolae, parallel, not covered with velum Apical pore field present on each apex, mostly composed of three rows of porelli present on each apex, with many round neatly arranged porelli present on each apex with 6 8 rows of porelli present on each apex, porelli irregularly arranged present on each apex, composed of parallel slits Ocellimbus very shallow large and depressed small and deep small, not depressed shallow Rimoportula one per valve, open externally as a slit two per valve (rarely one), open externally as a pore or short slit one per valve, open externally in a simple pore, on one side of the valve one per valve, open externally as round pore one per valve, perpendicular or oblique to apical axis Cingulum composed of one band with one row of fine poroids several closed bands with one row of poroids three or more open bands open bands with one row of poroids several incomplete open bands with a single row of poroids a new diatom from Iraq Phytotaxa 244 (3) 2016 Magnolia Press 295

8 References Al-Handal, A.Y., Abdullah, D.S., Wulff, A. & Abdulwahab, D. (2014) Epiphytic diatoms of the Mesopotamian wetland: Huewaiza marsh, South Iraq. Diatom 30: Cejudo-Figueiras, C., Morales, E.A., Wetzel, C.E., Blanco, S., Hoffmann, L. & Ector, L. (2011) Analysis of the type of Fragilaria construens var. subsalina (Bacillariophyceae) and description of two morphologically related taxa from Europe and the United States. Phycologia 50: Compère, P. (2001) Ulnaria (Kützing) Compère, a new genus name for Fragilaria subgen. Alterasynedra Lange-Bertalot with comments on the typification of Synedra Ehrenberg. In: Jahn, R., Kociolek, J.P., Witkowski, A. & Compère, P. (Eds.) Lange-Bertalot Festschrift. Studies on diatoms dedicated to Prof. Dr. h.c. Horst Lange-Bertalot on the occasion of his 65th birthday. A.R.G. Gantner Verlag K.G., Ruggell, pp Edlund, M.B., Morales, E.A. & Spaulding, S.A. (2006) The type and taxonomy of Fragilaria elliptica Schumann, a widely misconstrued taxon. In: Witkowski, A. (Ed.) Proceedings of the Eighteenth International Diatom Symposium, Miedzyzdroje, Poland 2nd - 7 th September Biopress Limited, Bristol, pp Ehrenberg, C.G. (1830) Organisation, Systematik und geographisches Verhältniss der Infusionsthierchen. Zwei verträge. Druckerei der Königlichen akademie der wissenschaften, Berlin, 108 pp. Garcia, M. (2006) The transfer of Fragilaria obtusa Hustedt to the genus Staurosira Ehrenberg (Bacillariophyceae). Phycological Research 54: Graeff, C.L., Kociolek, J.P. & Rushforth, S.R. (2013) New and interesting diatoms (Bacillariophyta) from Blue Lake Warm Springs, Tooele County, Utah. Phytotaxa 153 (1): Grunow, A. (1862) Die osterreichischen Diatomeen nebst Anschluss einiger neuen Arten von andern Lokalitaten und einer kritischen Ubersicht der bisher bekannten Gattungen und Arten. Erste Folge. Epithemieae, Meridioneae, Diatomeae, Entopyleae, Surirelleae, Amphipleureae. Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien 12: Hamilton, P.B. & Siver, P.A. (2008) The type for Fragilaria lancettula Schumann 1867 and transfer to the genus Punctastriata as P. lancettula (Schum.) Hamilton & Siver comb. nov. Diatom Research 23: Hasle, G.R., Medlin, L.K. & Syvertsen, E.E. (1994) Synedropsis gen. nov., a genus of araphid diatoms associated with sea ice. Phycologia 33 (4): Kützing, F.T. (1844) Die Kieselschaligen Bacillarien oder Diatomeen. Zu finden bei W. Köhne, Nordhausen, 152 pp. Lange-Bertalot, H. & Ulrich, S. (2014) Contribution to the taxonomy of needle-shaped Fragilaria and Ulnaria species. Lauterbornia 78: Lyngbye, H.C. (1819) Tentamen hydrophytologiae danicae continens omnia hydrophyta cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusque cognita, systematice disposita, descripta et iconibus illustrata, adjectis simul speciebus norvegicis. Typis Schultzianis, in commissis Librariae Gyldendaliae, Copenhagen, 248 pp. Morales, E.A. (2001) Morphological studies in selected fragilarioid diatoms (Bacillariophyceae) from Connecticut waters (U.S.A.). Proceedings of the Academy Natural Sciences of Philadelphia 151: Morales, E.A. (2003) On the taxonomic status of the genera Belonastrum and Synedrella proposed by Round and Maidana (2001). Cryptogamie Algologie 24: Morales, E.A. (2005) Observations of the morphology of some known and new fragilaroid diatoms (Bacillariophyceae) from rivers in the USA. Phycological Research 53: Morales, E.A. (2006) Staurosira incerta (Bacillariophyceae) a new fragilarioid taxon from freshwater systems in the United States with comments on the structure of girdle bands in Staurosira Ehrenberg and Staurosirella Williams et Round. In: Ognjanova-Rumenova, N. & Manoylov, K. (Eds.) Advances in phycological studies. Festschrift in Honour of Prof. D. Temniskova-Topalova. Pensoft Publishers & University Publishing House, Sofia, Moscow, pp Phytotaxa 244 (3) 2016 Magnolia Press AL-HANDAL ET AL.

9 Morales, E.A., Manoylov, K.M. & Bahls, L.L. (2010) Three new araphid diatoms (Bacillariophyta) from rivers in North America. Proceedings of the Academy Natural Sciences of Philadelphia 160: Morales, E.A., Novais, M.H., Chávez, G., Hoffmann, L. & Ector, L. (2012) Diatoms (Bacillariophyceae) from the Bolivian Altiplano: three new araphid species from the Desaguadero River draining Lake Titicaca. Fottea 12: Morales, E.A., Guerrero, J.M., Wetzel, C.E., Sala, S. & Ector, L. (2013) Unravelling the identity of Fragilaria pinnata Ehrenberg and Staurosira pinnata Ehrenberg: research in progress on a convoluted story. Cryptogamie Algologie 34: Prasad, A.K.S.K. & Livingston, R.J. (2005) Fine structure and taxonomy of Synedropsis karsteteri sp. nov. (Fragilariaceae, Bacillariophyta), a bloom-forming, brackish-water, planktonic araphid diatom from Perdido Bay, northeastern Gulf of Mexico. Diatom Research 20: Prasad, A.K.S.K., Nienow, J.A. & Riddle, K.A. (2001) Fine structure, taxonomy, and systematics of Reimerothrix (Fragilariaceae, Bacillariophyta), a new genus of synedroid diatoms from Florida Bay, USA. Phycologia 40: Round, F.E., Crawford, R.M. & Mann, D.G. (1990) The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp. Williams, D.M. & Round, F.E. (1986) Revision of the genus Synedra Ehrenberg. Diatom Research 1: Williams, D.M. & Round, F.E. (1987) Revision of the genus Fragilaria. Diatom Research 2: Williams, D.M. & Round, F.E. (1988) Fragilariforma, nom. nov., a new generic name for Neofragilaria Williams & Round. Diatom Research 3: Williams, D.M. Chudaev, D.A. & Gololobova, M.A. (2009) Punctastriata glubokoensis spec. nov., a new species of fragilarioid diatom from Lake Glubokoe, Russia. Diatom Research 24: a new diatom from Iraq Phytotaxa 244 (3) 2016 Magnolia Press 297

The Transfer of Two Japanese Synedra Species (Bacillariophyceae) to the Genus Ulnaria

Bull. Natl. Mus. Nat. Sci., Ser. B, 35(1), pp. 11 16, March 22, 2009 The Transfer of Two Japanese Synedra Species (Bacillariophyceae) to the Genus Ulnaria Akihiro Tuji Department of Botany, National Museum