Morphology and Taxonomy of Some Rare Chlorococcalean Algae (Chlorophyta)*

Biologia 63/6: 781—790, 2008 Section Botany DOI: 10.2478/s11756-008-0099-7

Morphology and taxonomy of some rare chlorococcalean algae (Chlorophyta)*

František Hindák & Alica Hindáková

Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 14,SK-84523 Bratislava, Slovakia; e-mail: [email protected]; [email protected]

Abstract: The morphologies of 15 rare chlorococcalean algae, i.e. three species of the Characiaceae [Hydrianum crassiapex Korshikov,H.viride(Scherffel) H. Ettl, Characiellopsis skujae (Fott) Komárek], four taxa of the genus Pediastrum Meyen [Pediastrum privum (Printz) E. Hegewald, P. duplex Meyen var. rugulosum Raciborski, P. angulosum (Ehrenberg) ex Meneghini, Pediastrum biradiatum Meyen], a radiococcalean alga Phacomyxa sphagnicola Skuja, Pseudodictyosphaerium fluviatile (Hindák) Hindák from the Dictyosphaeriaceae, three representatives of the family Oocystaceae (Amphikrikos minutissimus Korshikov, Gloeotaenium loitlesbergianum Hansgirg, Chlorolobion obtusum Korshikov) and three species of the genus Scenedesmus Meyen (S. ginzbergeri Kammerer, S. incrassatulus Bohlin, S. parisiensis Deflandre), are documented by drawings and micrographs and their taxonomy is discussed. Of these, Hydrianum viride, Pediastrum duplex var. rugulosum, Scenedesmus ginzbergeri and S. parisiensis are recorded for the first time in Slovakia. Key words: coccoid green algae; morphology; taxonomy; Slovakia; Poland; Canada

Introduction Material and methods

Algal samples were collected from the plankton or periphy- Within the algal flora of Slovakia project, special at- ton of different types of water bodies, mostly from eutrophic tention has been paid to the phytoplankton and phy- running waters (e.g., the Morava and Danube rivers and tobenthos diversity of the Danube and Morava rivers their oxbows and inundation lakes in Bratislava and South- (cf. Hindák 2004; Hindák & Hindáková 2004), and of ern Slovakia) or from stagnant water bodies (mainly from small shallow man-made water bodies such as gravel gravel and sand pit lakes in Bratislava or its surroundings in and sand pit lakes within the city limits of Bratislava Western and Southern Slovakia). In some cases foreign ma- (cf. Hindák & Hindáková 2004). Occasionally, samples terial was also investigated, originating from Canadian and from dystrophic waters, mainly from peat-bogs, have Finnish lakes, as well as from peat-bogs in Poland (Bor na also been analysed. In spite of many studies devoted Czerwionym near Nowy Targ, dystrophic lakes Kuzniczek to the diversity and taxonomy of algae in these habi- near Poznań, and Soltys near Warsaw). In Slovakia we studied acidophilic algae from the peat-bog Bor near Suchá Hora tats, there are still many unanswered questions. Many in the Oravské Beskydy Mts. A plankton net of 10 µm of these relate to the fact that knowledge of the mor- mesh size was mostly used for phytoplankton samplings. phological variation of cells and colonies during their Studies were performed on living material. Light microscope life cycles and, consequently, of their exact position in observations were carried out with a Leitz Diaplan micro- the taxonomic system is insufficient. scope, and photomicrographs were taken with a Wild Pho- In this contribution 15 rare taxa of chlorococcalean toautomat MPS45. Original drawings were usually made are presented, including four that are new records for from micrographs. Preserved material in formaldehyde is the algal flora of Slovakia [Hydrianum viride (Scherf- stored at the Institute of Botany SAS, Bratislava. Komárek fel) H. Ettl, Pediastrum duplex Meyen var. rugulo- & Fott’s (1983) classification system of the Chlorococcales (Chlorophyceae) is adopted in the algal flora of Slovakia sum Raciborski, Scenedesmus ginzbergeri Kammerer, databank. S. parisiensis Deflandre]. According to our observations, the genus Amphikrikos Korshikov with its type species A. minutissimus should be placed in the fam- Results and discussion ily Oocystaceae on the basis of the expanded cell wall of autosporangia. Further, the morphology of solitary A selection of 15 algae belonging to the Chlorococcales cells and young autosporangia in Gloeotaenium loitles- sensu Komárek & Fott (1983) is presented below. Taxa bergianum Hansgirg is described for the first time. found for the first time in the territory of Slovakia (cf.

* Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.

c 2008 Institute of Botany, Slovak Academy of Sciences 782 F. Hindák & A. Hindáková

Chytridiochloris viridis (Scherffel) Pascher 1939; Acro- chasma uncum Korshikov 1953, incl. f. apodum H. Ettl 1968; A. viride (Scherffel) Fott 1975; Hydrianum hori- zontale Korshikov 1953] On the filaments of Microspora collected from the peat bog Bor near Suchá Hora (see above) we also found other attached algae, including loricae of Lepochro- mulina simplex Fott (Chrysophyceae, Fig. 5) and an- other representative of the genus Hydrianum, H. viride. The latter differed markedly from H. crassiapex by its elongated, curved cells with an obtuse apex, measuring 18 × 2.5 µm. The chloroplast was parietal, extending to the ends of the cells, without a pyrenoid. Zoospores were not observed. The species has been described under various names (see synonyms) and has been found in Germany, Austria, Ukraine, Romania, Sweden and the Czech Re- public (cf. Komárek & Fott 1983). Its life cycle, especially the production of biflagellated zoospores, was studied in detail by Ettl (1978).

Characiellopsis skujae (Fott) Komárek 1979 (Figs µ Fig. 1. Hydrianum crassiapex Korshikov; scale 10 m. 8, 9) (synonyms: Characium obtusum A. Braun sensu Kor- shikov 1953 and Skuja 1964; Characium skujae Fott Hindák & Hindáková 1998) are marked with an asterisk 1975) (*). Cells solitary, elongated ovoid, narrowing at the base, 24–40 × 12–30 µm, with a short thick stalk, attached Hydrianum crassiapex Korshikov 1953 (Figs 1–5) by a distinct brown holdfast. Cell walls thick, at the (synonym: Characiopsis galeata H. Ettl 1956) apex with a refractive ring-shaped thickened inclu- Cells solitary, ovoid to slightly pyriform, 6–20 × 4– sion. Protoplast in old cells sometimes oval to broadly 6–(8) µm, attached by very short hyaline brownish oval, placed in the central part of widened cell wall stalk, to filaments of Microspora stagnorum (Kützing) (Fig. 8). Chloroplast massive, filling the entire cell, with Lagerheim. Cell wall strongly thickened into a coni- a pyrenoid. Reproduction not observed. cal rounded apex. Chloroplast parietal, massive, bright We found this species in the littoral zone of an green, without a pyrenoid. One big vacuole in the cen- oxbow of the Danube River in Bratislava-Rusovce, tral or lower part of adult cells, nucleus located near Sept. 2000, and in two peat bogs in Poland, Bor the apex. Protoplast dividing into 4 or 8 parts that are Na Czerwionym near Nowy Targ (S Poland, 2002) transformed into zoospores, liberated through a lateral and Kuzniczek near Poznań (W Poland, leg. Dr. P. aperture below the apical thickening of the wall. Usu- Owsianny, autumn 2002). The cells were attached to fil- ally one daughter cell remaining within the mother cell amentous green algae, mostly on Cladophora glomerata wall. Zoospores reported to be biflagellated, elongate, (L.) Kützing. This alga is listed as Characium obtusum pyriform (Korshikov 1953), not seen in our material. A. Braun in the checklist of cyanobacteria and algae of This species was described from a peat bog in Slovakia (Hindák & Hindáková 1998). Kharkov province, Ukraine, and classified in the fam- The taxonomy of this species is unclear. Accord- ily Characiaceae (Protococcales = Chlorococcales). The ing to the original diagnosis and figures given by A. morphology of our specimens from a peat bog Bor Braun (cf. Brunnthaler 1915), the most conspicuous near Suchá Hora, Oravské Beskydy Mts, NW Slovakia and unique feature of this characean alga is a ring- (leg. Mgr. A. Guttová, PhD., May 25, 2007) is in good shaped refractive inclusion at the apical part of cell agreement with the original description of Korshikov wall. The exact shape of the chloroplast in Characium (1953), Ettl’s (1956) description of a synonymous alga obtusum was depicted neither by A. Braun nor by Kor- Characiopsis galeata, and Fott’s findings from different shikov (1953). It was Skuja (1964) who observed a cen- parts of Bohemia and the High Tatra Mts, Slovakia tral asteroid chloroplast, clearly visible particularly in (cf. Komárek & Fott 1983). Our record of this species young cells. The shape of chloroplast led Fott (1975) to is the second of the territory of Slovakia (Hindák & establish a separate species, Characium skujae Fott. On Hindáková 1998). the basis of the asteroid chloroplast, Komárek (1979) transferred it into the genus Characiellopsis M.O.P. et *Hydrianum viride (Scherffel) H. Ettl 1978 (Figs 6, M.O.T. Iyengar 1932 as C. skujae (Fott) Komárek. A 7) central position of the chloroplast was also observed in [synonyms: Harpochytrium viride Scherfell 1926, bas.; cells of Characiella rukwae Schmidle (cf. Brunnthaler Morphology and taxonomy of rare chlorococcalean algae 783

Figs 2–5. Hydrianum crassiapex Korshikov (lorica of Lepochromulina simplex Fott visible in Fig. 5, upper left), 6, 7 H. viride (Scherﬀel) H. Ettl, 8, 9. Characiellopsis skujae (Fott) Komárek; scale 10 µm.

1915; Komárek & Fott 1983), in which reproduction by outer side with shallow concavity, inner cells penta- zoospores was also observed. According to Skuja (1964), or hexagonal, with straight sides. Chloroplast parietal, the shape of chloroplast in Characiellopsis skujae is as- with a pyrenoid. Zoospore release pores elongated, lo- teroid, as is most clearly seen in young cells. However, cated centrally in empty zoosporangial cells. the chloroplast in adult and especially old cells covers According to Komárek & Fott (1983) and Komá- all peripheral parts of the cells and therefore no aster- rek & Jankovská (2001), this species is characterized oid structure is discernable, and sometimes no pyrenoid by a boreo-alpine distribution. It has been observed in can be seen (Fig. 9). However, an apical ring on the cell northern countries of the temperature zone up to sub- wall is well visible during its entire life cycle. These ob- arctic regions of Europe and Canada, and also in high servations suggest to us that it is best either to retain mountain lakes in Peru (Hegewald & Schnepf 1979). the name Characium obtusum A. Braun for this species, We found it in plankton samples from central Canada, or to assign it to a new genus. Manitoba, South Indian Lakes (leg. Dr. H. Kling, summer 1987, Fig. 10). In Slovakia, this species has been Pediastrum privum (Printz) E. Hegewald in E. Hege- recorded only once in the plankton of the Danube River wald et Schnepf 1979 (Figs 10, 11) in Bratislava (Hindák 2004; Fig. 11), apparently repre- (basionym: Pediastrum integrum var. privum Printz senting material that had drifted into an upstream part 1913) of river from an Alpine lake in Austria. Four-celled coenobia with a more or less square shape, up to 15 µm diagonally, eight-celled coenobia more or *Pediastrum duplex Meyen var. rugulosum Raci- less circular, up to 22 µm in diameter, without gaps borski 1890 (Figs 12, 13) between cells. Marginal cells tri- to pentagonal, on the Coenobia 16–64-celled, circular to oval, up to 150 µm 784 F. Hindák & A. Hindáková

Figs 10, 11. Pediastrum privum (Printz) E. Hegewald in E. Hegewald et Schnepf, 12, 13 P. duplex Meyen var. rugulosum Raciborski, 14, 15. P. angulosum (Ehrenberg) ex Meneghini, 16, 17. P. biradiatum Meyen 1829; scale 10 µm. or more in diameter, with gaps between cells and with nant waters, especially in gravel pit lakes and oxbows a mucilaginous layer. Cell walls finely and ± regularly (Hindák & Hindáková 1998, 2008). The coenobium granulated. Cells to 25 µmindiameter. showninFig.14camefromtheČíčovskémŕtverameno Our material differs from the type variety of the oxbow situated near the Danube, S Slovakia (Hindák & species by the granulated cell walls that are clearly Hindáková 1998, 2003, 2004, 2008), the coenobium on visible especially in empty cells. The alga was com- Fig. 15 from Saimaa Lake, W Finland (leg. Dr. S. Zwer- monly found in the littoral of oxbows of the Danube ver, summer 2007). and Morava rivers; illustrated coenobia came from the periphyton of the Číčovské mŕtve rameno, an oxbow of Pediastrum biradiatum Meyen 1829 (Figs 16, 17) theDanubeinSSlovakia. Coenobia (8)–16–32-celled, circular in outline, up to 150 µm in diameter, with regular holes. Marginal cells with Pediastrum angulosum (Ehrenberg) ex Meneghini concave sides and two radiating long lobes, which are 1840 (Figs 14, 15) divided again into conical lobes. Cell walls smooth. Coenobia 32–64–(128)-celled, circular, oval or irregular It occurs sporadically in the plankton and periphy- in shape, up to 300 µm in diameter, without gaps. Cells ton of lakes and rivers. In Slovakia it was found in the of P. boryanum-type, but additionally with irregular Danube and Morava rivers and in gravel pit lakes near net-like sculpture on the cell walls. Bratislava (Hindák & Hindáková 1998a,b, 2003, 2004). The species is conspicuous by a superficial net- like layer on the cell wall. It has been recorded rarely, Phacomyxa sphagnicola Skuja 1956 (Figs 18–21) but has a cosmopolitan distribution (Komárek & Fott (synonyms: Dispora speciosa Korshikov 1953, D. cru- 1983). In Slovakia, we found it in the periphyton of stag- cigenoides Printz sensu Korshikov 1953) Morphology and taxonomy of rare chlorococcalean algae 785

Figs 18–21. Phacomyxa sphagnicola Skuja, 22–25. Pseudodictyosphaerium ﬂuviatile (Hindák) Hindák; scale 10 µm.

Colonies spherical to irregular plates, 4–16-celled, rarely peat bogs in Poland, i.e. Kuzniczek near Poznań(leg. more-celled or in diads, embedded in a wide, hyaline Dr. P. Owsianny, 2003) and Soltys in Central Poland mucilaginous envelopes, up to 50 µm in diameter. Cells (leg. Prof. G. Tomasiewicz, 2003). globose, semiglobose or slightly angular, 6–8–(10) µm. Chloroplast parietal, without a pyrenoid. Reproduction Pseudodictyosphaerium fluviatile (Hindák 1978) by binary cell divisions in a plane that is perpendicular Hindák 1978 (Figs 22–25, 56) to that of the previous division. (basionym: Dictyosphaerium fluviatilis Hindák 1978) The fate of the mother cell walls after the proto- Colonies spherical to broadly oval, up to 120 µmin plast division is not known, thus the exact taxonomic diameter, with cells ± densely adjoined at the ends position of the alga is unclear. According to Komárek of dichotomously arranged cell wall halves. Adult cells & Fott (1983), the mother cell wall gelatinizes, and spherical, young cells broadly oval, hemispherical to therefore they assigned it to the family Radiococcaceae. spherical, 6–8 µm in diameter. Chloroplast parietal, The species Dispora speciosa Korshikov 1953 and D. trough-shaped, with a naked pyrenoid. Small to rela- crucigenoides Printz sensu Korshikov 1953 are syn- tively large drops of oil are conspicuous within the pro- onymous with Phacomyxa sphagnicola,sincethetype toplast. Autospores two, released by longitudinal divi- species of the genus Dispora Printz, D. crucigenoides sion of the mother cell wall into two halves. Printz, has cells composed of two parts as in the genus This taxon differs from other species of Pseudodic- Radiofilum Schmidle. tyosphaerium Hindák 1978 and Dictyosphaerium Nägeli The species has been found in dystrophic lakes 1849 by the formation of two autospores, and from of many Central European and Nordic countries (see the latter genus by the absence of a starch associated Komárek & Fott 1983). Our material originated from pyrenoid in the chloroplast (Komárek & Fott 1983). 786 F. Hindák & A. Hindáková

Figs 26–31. Amphikrikos minutissimus Korshikov; scale 10 µm.

Amphikrikos minutissimus Korshikov 1953 (Figs (Thompson) Hindák which led to its assignment to the 26–31, 57) genus Granulocystopsis, family Oocystaceae. However, Cells solitary or arranged in 4–8-celled autosporan- the taxonomy of all mentioned genera required further gia, with indistinct hyaline mucilaginous envelopes, 10– studies which should also include ultrastructural and 15–(35) × 6–12–(23) µm. Cells short cylindrical to molecular methods. cylindrical-oval, 5–7 × 2–3.5 µm, with conically to Amphikrikos minutissimus was recorded from the shortly attenuated ends and with a ring of irregular plankton of rivers and gravel-pit lakes in Bratislava (De- brown granules at both poles. Chloroplast parietal, with vín, Štrkovec, etc.). a pyrenoid. Autospores 4–8, from the onset arranged closely together in expanded mother cell walls. Gloeotaenium loitlesbergianum Hansgirg 1890 The genus Amphikrikos was originally described (Figs 32–39) with one species, A. minutissimus, but later three other Colonies/autosporangia oval to elliptical, 2-celled up species were established (Hindák 1977, 1988, Komárek to 60 × 40 µm, 4-celled up to 60 µmindiameter, & Fott 1983). The genus was considered by Korshikov free, with broad hyaline mucilaginous envelopes. Cells (1953) as a member of the Oocystaceae family, but broadly asymmetrically oval, 18–35 × 15–20 µm, in Hindák (1977) and Komárek & Fott (1983) placed it in colonies separated each other by a hyaline or grey to the family Chlorellaceae on the basis, that the mother black stratiﬁed layer of the mother cell wall in form of a cell walls do not markedly expand before liberation of transverse band (in 2-celled colonies) or a diagonal cross autospores. In view of the fact that in the type of the (in 4-celled colonies) containing calcite crystals on the genus, A. minutissimus, the autospores are released by surface. In addition, a small accumulation of the same rupture of a non-expanded mother cell wall, Hindák structure and colour is observed at the ends and sides of (1977) erected two new oocystacean genera, i.e. Gran- the colony. Cell wall thick, conspicuously enlarged and ulocystis for taxa with granulation covering the whole longitudinally stratiﬁed in young autosporangia (Figs surfaceofthecellwalls,andGranulocystopsis for algae 38, 39). Chloroplast massive, parietal, in young cells with strictly localized cell wall ornamentations. asteroid, with a large starch-associated pyrenoid. Re- The observations presented here lend support for production by autospores. Autospores after releasing a transfer of the genus Amphikrikos with the type from the mother cell wall solitary, asymmetrically oval, species A. minutissimus to the family Oocystaceae, as with longitudinally arranged long and thin calcite crys- the cell walls of autosporangia expanded considerably tals on the surface (Figs 35, 36) and with a distinct before liberation of autospores. A similar observation hyaline mucilage. was made by Comas (1986) in Amphikrikos hexacosta According to Komárek & Fott (1983), this species Morphology and taxonomy of rare chlorococcalean algae 787

Figs 32–39. Gloeotaenium loitlesbergianum Hansgirg; scale 10 µm.

Figs 40–45. Chlorolobion obtusum Korshikov; scale 10 µm. 788 F. Hindák & A. Hindáková

Figs 46, 47. Scenedesmus ginzbergeri Kammerer, 48, 49. S. incrassatulus Bohlin, 50–55 S. parisiensis Deflandre; scale 10 µm. has a cosmopolitan distribution but is more common in more convex than the other, bluntly rounded, 35–45 × tropical than in temperate zones. The illustrated spec- 7–12 µm, usually attached by one end or laterally to imens were collected from the littoral of the Číčovské substrate. Chloroplast parietal, massive, plate-shaped, mŕtve rameno – oxbow near the Danube, S Slovakia with a large starch associated pyrenoid in the central (Hindák & Hindáková 1998b, 2008). The species was part. Numerous oil drops of different sizes in all proto- also observed in similar small water bodies elsewhere plast. Reproduction by autospores released by gelatin- in this region (Hindák 2004). isation of mother cell walls. Like the original finding in the North European Chlorolobion obtusum Korshikov 1953 (Figs 40–45) part of Russia (Korshikov 1953), the cells in our mate- Cells solitary or in (4)–8-celled groups after autospore rial from the peat bogs Kuzniczek near PoznańinW formation, asymmetrical, slightly bent, with one side Poland: (leg. Dr. P. Owsianny, 2003) and Soltys in sur- Morphology and taxonomy of rare chlorococcalean algae 789

Figs 56. Pseudodictyosphaerium fluviatile (Hindák) Hindák, 57. Amphikrikos minutissimus Korshikov, 58. Scenedesmus ginzbergeri Kammerer, 59. S. incrassatulus Bohlin, 60. S. parisiensis Deflandre; scale 10 µm. roundings of Warsaw (leg. Prof. G. Tomasziewicz, 2003) rounded ends, 11–16 × 2.5–3.5 µm, embedded in broad were mostly attached on empty armours of Crustacea mucilaginous envelopes. or were free-floating secondarily. The geographical distribution of the species is not very well known, although it is easily distinguished from *Scenedesmus ginzbergeri Kammerer 1938 (Figs 46, similar species, namely by compact and slightly arcu- 47, 58) ated coenobia (cf. Hindák 1990). Our studied material Coenobia usually 8-celled, rarely 4-celled, with cells lin- originated from the littoral of the Číčovské mŕtve ra- early to slightly alternately arranged in one row, 15–33 meno oxbow, S Slovakia (Hindák & Hindáková 2008). µm long, without a mucilaginous envelope. Cells irreg- ularly spindle-shaped, inner cells straight, outer cells *Scenedesmus parisiensis Deflandre 1924 (Figs 50– slightly curved, with acute ends, 15–22 × 2–3.5 µm. 55, 60) Cell wall smooth. (?synonyms: Scenedesmus producto-capitatus var. pla- This species resembles S. obliquus (Turpin) Kütz- nus Roll, see Korshikov 1953, Fig. 372D; S. polyglobulus ing, but differs by cells alternating only slightly in Hortobágyi 1959; S. polyglobulus forma sensu Comas & single row coenobia. A similar linear arrangement of Komárek 1983) cells in a coenobium is observed in Enallax acuti- Coenobia in one row, without or with slightly alter- formis (Schröder) Hindák which was also found in the nating cells, 2-celled 5–7 µm in diameter, 4-celled 9–15 Číčovské mŕtve rameno oxbow (Hindák 1990; Hindák µm long, linear, without mucilaginous envelopes. Cells & Hindáková 1998b). However, the latter species has elongated, inner cells straight, outer cells slightly bent cells with longitudinally list-like hyaline ribs. to lunate, 6–12 × 2–3 µm. Cell ends attenuated, with According to Komárek & Fott (1983), this species several short teeth-like spines at apexes; similar spines was recorded from tropical regions in S America (see sparsely developed on lateral parts of outer cells. also Hegewald et al. 1980). Judging on published illus- Due to the formation of 2–4-celled coenobia and trations, it was also found in Europe, but was referred short teeth-like apical and lateral spines, the stud- to by different names [e.g. S. acutus var. anteniformis ied specimens appear to represent S. parisiensis De- Uherkovich (Uherkovich 1966, Hegewald & Silva 1988)]. flandre (see Hegewald & Silva 1988). Similar coenobia were also found in Scenedesmus producto-capitatus var. Scenedesmus incrassatulus Bohlin 1897 (Figs 48, planus Roll (cf. Korshikov 1953), S. polyglobulus Hor- 49, 59) tobágyi 1959 and S. polyglobulus forma sensu Comas & Coenobia 4–8-celled, slightly to markedly arcuated oval Komárek 1983 (see Komárek & Fott 1983). In the cells in outline, with cells in two alternated rows, 17–20 × of S. polyglobulus instead of teeth-like apical spines, 18–20 µm. Cells fusiform, slightly bent, with broadly brown globular incrustations are developed. However, 790 F. Hindák & A. Hindáková short teeth-like spines in top view (especially at low Hindák F. 1988. Studies on the chlorococcal algae (Chloro- magnification) or in old cells (Fig. 55) may appear as phyceae). IV. Biol. Práce, Bratislava, 34/1–2: 1–264. granules. Hindák F. 1990. Studies on the chlorococcal algae (Chloro- phyceae). V. Biol. Práce, Bratislava, 36: 1–228. This species was found in the littoral of the Hindák F. 2004. Planktónové chlorokokálne a ulotrichálne riasy Číčovské mŕtve rameno-oxbow near the Danube (Hin- rieky Dunaja a Moravy v Bratislave [Planktic chlorococcalean dák & Hindáková 2008). and ulotrichacean algae of the rivers Danube and Morava in Bratislava]. Zborn. Hydrobiol. kurzu 2004, Bratislava, pp. 4– 14. Acknowledgements Hindák F. & Hindáková A. 1998a. Zoznam siníc a rias Sloven- ska [Checklist of cyanophytes/cyanobacteria and algae of Slo- vakia], pp. 12–100. In: Marhold K. & Hindák F. (eds), Zoznam The authors are obliged to Prof. G. Tomaszewicz, Dr. H. nižších a vyšších rastlín Slovenska (Checklist of non-vascular Kling, Mgr. A. Guttová, PhD., RNDr. M. Kultanová, Mag. and vascular plants of Slovakia), Veda, Bratislava. S. Zwerver and Dr. P. Owsianny for providing material, and Hindák F. & Hindáková A. 1998b. Sinice/cyanobaktérie a ria- to Dr. H. Sluiman for correcting the English. This study is sy Národnej prírodnej rezervácie Číčovské mŕtve rameno a part of VEGA project No. 2/7069/27 supported by the (Cyanophytes/cyanobacteria and algae of the National Na- Slovak Academy of Sciences. ture Reserve Číčovské mŕtve rameno oxbow). Ochrana prírody, Banská Bystrica, 16: 17–24. Hindák F. & Hindáková A. 2003. Cyanophytes and algae of gravel References pit lakes in Bratislava, Slovakia. Hydrobiologia 506(1): 155– 162. Brunnthaler J. 1915. Protococcales. In: Pascher (ed.), Die Hindák F. & Hindáková A. 2004. Diverzita fytoplanktónu rieky Süsswasserflora Deutschlands, Osterreichs¨ und der Schweiz, Moravy a Dunaja v Bratislave r. 2003 (Diversity of phyto- Jena, 5: 52–205. plankton of the Morava and Danube rivers in Bratislava in Comas A. 1986. Beiträge zur Kenntnis der Oocystaceae (Chlorel- 2003). Bull. Slov. Bot. Spoločn., Bratislava, 26: 9–17. lales) aus Kuba. Arch. Hydrobiol., Suppl. 73.2,Algol.Stud. Hindák F. & Hindáková A. 2008. Diverzita cyanobaktérií a rias 43: 233–237. NPR Číčovské mŕtve rameno (J. Slovensko) [Diversity of Comas A. & Komárek J. 1984. Taxonomy and nomenclature of cyanobacteria and algae of the National Nature Reserve several species of Scenedesmus (Chlorellaceae). Arch. Hydro- Číčovské mŕtve rameno oxbow (Southern Slovakia)]. Bull. biol., Suppl. 67.2,Algol.Stud.35: 135–157. Slov. Bot. Spoločn., Bratislava, 30 (in press) Ettl H. 1978. Uber¨ Hydrianum viride (Characiaceae, Chloro- Komárek J. 1979. Änderungen in der Taxonomie der Chlorokok- phyceae), seine Fortpflanzung und Taxonomie. Pl. Syst. Evol. kalalgen. Arch. Hydrobiol., Suppl. 56,Algol.Stud.24: 239– 129: 209–219. 263. Hegewald E., Schnepf E. & Aldave A. 1980. Investigations on Komárek J. & Fott B. 1983. Chlorophycae (Grünalgen), Ord- the lakes of Peru and their phytoplankton. The algae of La- nung: Chlorococcales. Die Binnnengewässer, Stuttgart, 16/7: guna Piurray and Laguna Huaypo, Cuzco, with special refer- 1–1044. ence to Franceia, Oocystis and Scenedesmus. Arch. Hydro- Korshikov O.A. 1953. Pidklas Protokokovi (Protococcinae). Vizn. biol./Suppl. 51, Algol. Stud. 25: 387–420. Prisnovod. Vodorostei Ukrainskoi RSR, Kiev, 5: 1–436. Hegewald E. & Silva P.C. 1988. Annotated catalogue of Scene- Skuja H. 1956. Taxonomische und biologische Studienuber ¨ das desmus and nomenclaturely related genera, including original Phytoplankton schwedischer Binnengewässer. Nova Acta Soc. description and figures. Bibliotheca Phycologica, J. Cramer, Sci. Upsal., Uppsala, Ser. 4, 18(3): 1–465. Stuttgart, 10: 1–587. Skuja H. 1964. Grundzüge der Algenflora und Algenvegetation Hindák F. 1977. Studies on the chlorococcal algae (Chloro- der Fjeldgegenden um Abisko in Schwedisch-Lappland. Nova phycea). I. Biol. Práce, Bratislava, 23/4: 1–192. Acta Soc. Sci. Upsal., Uppsala, 16(3): 1–404. Hindák F. 1978a. New taxa and reclassifications in the Chloro- Uherkovich G. 1966. Die Scenedesmus-Arten Ungarns. Akadémiai coccales (Chlorophyceae). Preslia 50: 97–109. Kiadó, Budapest. Hindák F. 1978b. The genus Lagerheimia Chod. and Lagerhei- mia-like unicells in the genus Scenedesmus Meyen (Chloro- Received September 1, 2007 phyceae). Biológia 33: 795–808. Accepted March 17, 2008