The Green Alga Askenasyella (Tetrasporales) In MichiganSkip other details (including permanent urls, DOI, citation information)
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. Please contact firstname.lastname@example.org to use this work in a way not covered by the license. :
For more information, read Michigan Publishing's access and usage policy.
Page 33 ï~~2009 THE MICHIGAN BOTANIST 33 THE GREEN ALGA ASKENASYELLA (TETRASPORALES) IN MICHIGAN Daniel E. Wujek Department of Biology Central Michigan University Mt. Pleasant, Michigan 48859 ABSTRACT The green alga Askenasyella chlamydopus is reported for Michigan for the first time. The genus Chaetochloris is shown to be a taxonomic synonym of Askenasyella and the species described within the former genus are transferred to Askenasyella. Askenasyella, traditionally placed in the family Palmellaceae, is shown to possess pseudocilia, and thus is more correctly placed in the family Tetrasporaceae. KEYWORDS: Askenasyella; Chaetochloris; Tetrasporaceae INTRODUCTION The genus Askenasyella was described by Schmidle (1902) with the single species, A. chlamydopus. The generic name refers to the Russian-German phycologist Eugena Askenasy. The genus was regarded by Schmidle as in the Xanthophyceae. In 1905, West & West described the taxon Actinobotrys confertus. Soon after, West & West (1906) recognized that their genus was congeneric with Schmidle's Askenasyella and they transferred their species to that genus, as Askenasyella conferta (W. West & G.S. West) W. West & G.S. West. Printz (1927) continued to assign Askenasyella to the Xanthophyceae, that is, the Botryococcaceae within his "Heterocontae". Printz recognized two species, A. chlamydopus and A. conferta. Pascher (1939) observed the presence of starch and thus transferred Askenasyella to the green algae, placing it in the family Palmellaceae, order Tetrasporales. Pascher stated that A. conferta was incompletely or not fully observed and that even if recognized as distinct, it may even be a taxon belonging to the genus Stichogloea Chodat. Ramanathan (1968) described a third species from India, A. randhawai. Askenasyella chlamydopus has been rarely reported from North America (Smith 1950; Woodson & Holoman 1964). The latter record was repeated by Dillard (1989). The current placement of Askenasyella is in question. Some phycologists (Pascher 1939; Smith 1950) place the genus in the family Palmellaceae whereas Bourrelly (1966) assigned it to the Radiococcaceae. Dillard (1989) placed it in the Oocystaceae of the Chlorococcales. Indeed, in the most recent systematic and ecological treatment of nonmotile coccoid and colonial green algae for North America (Shubert 2003), no attempt was made to place Askenasyella in a particular order or family. Based on observations of Kansas and Michigan sam
Page 34 ï~~34 THE MICHIGAN BOTANIST Vol. 48 pies containing Askenasyella, I make additional observations on its morphology and present a resolution of ordinal and family placement. MATERIAL AND METHODS Plankton samples were collected from an 1-70 turnpike marsh, Douglas County, west of Lawrence, Kansas, July 1968. Additional samples containing Askenasyella were collected from Miller's Marsh, Charlevoix County, Michigan, July, 1990. Maintenance cultures were grown in Bold's Basal Medium (1967) or soil water extract. Cultures no longer survive. RESULTS AND DISCUSSION The anterior end of the cell is at first truncated presenting a flat surface of contact with the substratum (Figs. 1-2). As a colony becomes crowded, the mutual pressure forces the cells away from the surface and the anterior position of the cell envelope becomes pointed. With further secretion of gel the individual cells come to lie remote from one another. The contiguous portion of the two pseudocilia from protoplast to apex is clearly evident (Fig. 2). This condition also arises in small colonies under observation with the microscope. It is thought that here both the pressure of the cover slip and subsequent additions of distilled water to the mount produce the change. In this condition if one failed to observe the pseudocilia, and they are nearly invisible when unstained, one could only determine their material as Askenasyella. The only clearly distinguishable portion of the pseudocilia is that which traverse the anterior part of the cell. Bourrelly (1966) was aware of the presence of pseudocilia and stated that "perhaps pseudoflagella" (French translation) were present as was Dillard (1989; called delicate threads). Neither author, however, acknowledged their presence in their systematic placements of the genus. The writer is certain that just such a failure in observations led to the earlier reports of Askenasyella in Kansas (Thompson, in Smith 1950) and Virginia (Woodson & Holoman 1964). The writer is further of the opinion that the description of Askenasyella was also based on such an incomplete observation. Because there are no other differences between this genus and Chaetochloris Pascher & Korshikov (in Korshikov 1932) and because Askenasyella has priority, the species of Chaetochloris are transferred to it. Furthermore, as the only morphological feature which can be used to separate Askenasyella randhawai and A. chlamydopus is size, the latter being ca. 2 tm shorter and narrower, I conclude that those two taxa are conspecific. A. chlamydopus Schmidle 1902: 154, 157, figs. 1-3; the generitype =Synonym: A. randhawai Ramanathan (1968: 116, figs. 1-10) A. consociata (Pascher & Korshikov) Wujek nov. comb. =Basionym: Chaetochloris consociata Pascher & Korshikov (in Korshikov 1932: 594, figs. 67, 68) A. asocialis (Pascher) Wujek nov. comb. =Basionym: Chaetochloris asocialis Pascher (1940: 144, figs. 7-8, 9d)
Page 35 ï~~2009 THE MICHIGAN BOTANIST 35 2009 THE MICHIGAN BOTANIST 35 2 FIGURES 1-2. Askenasyella chlamydopus. 1. Whole colony. 2. Cells each with two pseudocilia. Scale bar = 10 m.
Page 36 ï~~36 THE MICHIGAN BOTANIST Vol. 48 A. depauperata (Pascher) Wujek nov. comb. =Basionym: Chaetochloris depauperata Pascher (1940: 143, figs. 1, 3, 5, 9c) A. scherffeliana (Pascher) Wujek nov. comb. =Basionym: Chaetochloris scherffeliana Pascher (1940: 144, figs. 4, 9b) =Basionym: Chaetochloris indica Iyengar: 1975, 29, fig. 1) Calcite may be crystallized out in the colonial gel and in such quantity that individual cells come to lie in pockets or deep wells in the mass. When stained with methylene blue the colony gel shrinks. Before that it stains bright redviolet and exhibits a radiate structure. Through this gel run the pseudocilia which seem to take very little of the stain and become only slightly more visible. The pseudocilia and the striae of dense gel became more apparent when stained with potassium iodide. In summary, based on the morphology of the above newly described presence of pseudocilia in Askenasyella, it is best placed in the order Tetrasporales, family Tetrasporaceae and not as previously treated (Table 1). Molecular data on Askenasyella and other members of the family including the closely related genus Polychaetochloris (Pascher 1940) are needed to establish if this is a natural family. Key to the species of Askenasyella: 1. More than two pseudocilia per cell.................................. Polychaetochloris 1. Only two pseudocilia per cell..............................................2. 2. Papilla at bases of pseudocilia not conspicuous........................ A. chlamydopus 2. Conspicuous papilla between bases of pseudocilia................................. 3. 3. Colony four or fewer cells............................................... A. asocialis 3. Colony multicellular.....................................................4. 4. Cells lacking stigmata and pyrenoids (stigmas present in zoospores)........ A. depauperata 4. Cells with stigmata, with or without pyrenoid..................................5. 5. Cells longer and more slender than in other species, stigma large in upper-third of cell............................................... A. scherffeliana 5. Cells broadly elliptical-egg shaped to almost spheroidal, axial pyrenoid; zoospores lack stigma...................................................................A. consociata TABLE 1. Systematic placement of Askenasyella. Author Class/Order Family Schmidle (1902) Xanthophyceae West & West (1906) Confervales Chlorotheciaceae Printz (1927) Xanthophyceae Botryococcaceae Pascher & Korshikov (1932) Tetrasporales Pseudociliaceae Pascher (1939) Tetrasporales Palmellaceae Smith (1950) Tetrasporales Palmellaceae Bourrelly (1966) Chlorococcales Radiococcaceae Ramanathan (1968) Chlorangiales Chlorangiaceae Dillard (1989) Chlorococcales Oocystaceae This study Tetrasporales Tetrasporaceae
Page 37 ï~~2009 THE MICHIGAN BOTANIST 37 ACKNOWLEDGEMENTS I thank Dr. J.C. Gillingham, Director of Central Michigan University's Biological Station, Beaver Island, for providing laboratory space and Dr. M.J. Wynne for nomenclatural assistance and reviewing and improving an early draft of the manuscript. Trevor Grabill provided the line drawing, Ryan Dziedzic assisted in the German translations, and Brian Roberts assisted in the preparation of the plate. Special thanks to the late Dr. R.H. Thompson for letting the author examine his notes on Askenasyella. LITERATURE CITED Bold, H.C. (1967). A laboratory manual for plant morphology. Harper & Row, New York, 123 pp. Bourrelly, P. (1966). Les Algues d'eau douce.Tome 1. Les Algues Verts. N. Boubee & Cie, Paris. 511 pp. Dillard, G.E. (1989). Freshwater algae of the southeastern United States. Part I. Chlorophyceae: Volvocales, Tetrasporales and Chlorococcales. Bibliotheca Phycologia 81, 202 pp. Iyengar, M.O.P. (1975). Contributions to our knowledge of South Indian algae-VIII. Proceedings of the Indian Academy of Science 81B: 29-60. Korshikov, A.A. (1932). Studies in the Vacuolate. I. Archiv fur Protistenkunde 78: 557-612. Pascher, A. (1939). Heterokonten. In: Kryptogamen-Flora von Deutschland, Osterreich und der Schweiz, (A. Rabenhorst, ed.), Vol. 11. Leipzig. 1092 pp. Pascher, A. (1940). Zur Kenntnis der Stisswassertetrasporalen I. Beihefte zum Botanischen Centralblatt 1: 462-487. Printz, H. (1927). Chlorophyceae. In: Die nattirlichen Pflanzenfamilien (A. Engler & K. Prantl, eds.), 2nd ed., 3. Verlag Wilhelm Engelmann, Leipzig. 463 pp. Ramanathan, K. R. (1968). Askenasyella randhawai sp. nov., a new Chlorophyceae from Madras and its systematic position. Phykos 7:112-116. Schmidle, W. 1902. Notizen zu einigen Stisswasseralgen. Hedwigia 41: 150-163. Shubert, L.E. (2003). Nonmotile Coccoid and Colonial Green Algae. In: Freshwater Algae of North America (J.D. Wehr & R. G. Sheath, eds.). Academic Press, NY, pp. 253-309. Smith, G.M. (1950). Fresh-water algae of the United States. 2nd ed. McGraw-Hill, New York, 719 pp. West, W. & G. S. West. (1905). A further contribution to the freshwater plankton of the Scottish Lochs. Transactions of the Royal Society of Edinburgh 41: 71-518. West, W. & G.S. West. (1906). A comparative study of the plankton of some Irish lakes. Transactions of the Royal Irish Academy 33: 77-116. Woodson, B.R. & V. Holoman. (1964). A systematic and ecological study of algae in Chesterfield County, Virginia. The Virginia Journal of Science 15: 51-70.