This article was downloaded by: [University of Saskatchewan Library] On: 14 September 2012, At: 12:38 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Diatom Research Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tdia20 THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA (KÜTZING) BRÉBISSON (BACILLARIOPHYCEAE) AND THEIR TRANSFER INTO THE NEW GENUS DISCOSTELLA GEN. NOV. Václav Houk a & Rolf Klee b a Czech Academy of Sciences, Institute of Botany, Dukelská 135, CZ-379 82, Třeboň, Czech Republic b Bavarian Water Management Agency, Department of Aquatic Ecology Research, Demollstraße 31, D-82407, Wielenbach, Germany Version of record first published: 02 Nov 2011. To cite this article: Václav Houk & Rolf Klee (2004): THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA (KÜTZING) BRÉBISSON (BACILLARIOPHYCEAE) AND THEIR TRANSFER INTO THE NEW GENUS DISCOSTELLA GEN. NOV., Diatom Research, 19:2, 203-228 To link to this article: http://dx.doi.org/10.1080/0269249X.2004.9705871 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Transcript
This article was downloaded by: [University of Saskatchewan Library]On: 14 September 2012, At: 12:38Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registeredoffice: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
Diatom ResearchPublication details, including instructions for authors andsubscription information:http://www.tandfonline.com/loi/tdia20
THE STELLIGEROID TAXA OF THE GENUSCYCLOTELLA (KÜTZING) BRÉBISSON(BACILLARIOPHYCEAE) AND THEIRTRANSFER INTO THE NEW GENUSDISCOSTELLA GEN. NOV.Václav Houk a & Rolf Klee ba Czech Academy of Sciences, Institute of Botany, Dukelská 135,CZ-379 82, Třeboň, Czech Republicb Bavarian Water Management Agency, Department of AquaticEcology Research, Demollstraße 31, D-82407, Wielenbach, Germany
Version of record first published: 02 Nov 2011.
To cite this article: Václav Houk & Rolf Klee (2004): THE STELLIGEROID TAXA OF THE GENUSCYCLOTELLA (KÜTZING) BRÉBISSON (BACILLARIOPHYCEAE) AND THEIR TRANSFER INTO THE NEW GENUSDISCOSTELLA GEN. NOV., Diatom Research, 19:2, 203-228
To link to this article: http://dx.doi.org/10.1080/0269249X.2004.9705871
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
This article may be used for research, teaching, and private study purposes. Anysubstantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,systematic supply, or distribution in any form to anyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representationthat the contents will be complete or accurate or up to date. The accuracy of anyinstructions, formulae, and drug doses should be independently verified with primarysources. The publisher shall not be liable for any loss, actions, claims, proceedings,demand, or costs or damages whatsoever or howsoever caused arising directly orindirectly in connection with or arising out of the use of this material.
THE STELLZGEROZD TAXA OF THE GENUS CYCLOTELLA (KUTZING) B&BISSON
(BACILLARIOPHYCEAE) AND THEIR TRANSFER INTO THE NEW GENUS DISCOSTELLA GEN. NOV.
Vriclav Houk ' Czech Academy of Sciences, Institute of Botany, Dukelska 135,
CZ-379 82 TfeboA, Czech Republic
Rolf Klee Bavarian Water Management Agency, Department of Aquatic Ecology Research,
DemollstraJe 31 ,042407 Wielenbach, Germany
The valve morphology and ultrastructure of the the so-called "stelligeroid" taxa of the genus Cyclotella (Kutzing) Brkbisson (Bacillariophyceae) are discussed. These taxa have marginal fultoportulae and the rimoportula(e) positioned between costae. As this and other discussed characters do not fit the current description of the genus Cyclotella (Kutzing) Brkbisson nom. cons., the formal transfer of these taxa into a new genus, Discostella gen. nov., is proposed.
INTRODUCTION
The genus Cyclotella (Kutzing) BrCbisson 1838 nom. cons. differs from related genera by the presence of two different morphological patterns on one valve, where the radially striated marginal part surrounds a distinctly different central part. Several groups of species, each with the same essential morphological characters of the valves, can be distinguished within this genus. The positioning of the marginal fultoportulae (mfp) and rimoportula(e) (rp) and structure of the marginal and central part of the valve are particularly important. Within these groups, further differentiation at lower taxonomic levels, such as species, variety etc., is often problematic due to the variation in species morphology and morphological changes during the life cycle. Additionally, two different valves in one frustule, heterovalvy (one frustule with two different valve morphologies), can be found in many Cyclotella species. This heterovalvy is often not clearly stated or illustrated when a new taxon is being described, and nomenclatural and taxonomic uncertainty results. The diversity of some characters is sometimes better seen in the LM than in the SEM, mainly in the groups with the flat or transversely undulate valve centre. Differences in valve construction have led some authors to species groupings based on presence or absence of certain valve structures or ultrastructure (Lowe 1975, Serieyssol 1984, Haworth & Hurley 1986, Theriot & Serieyssol 1994, Loginova 1990a,b), or resulting from observations of the characters in the light microscope (Hikansson in Krammer & Lange-Bertalot 199 1, 2000). Recently Hikansson (2002) removed the group with complex alveolate structure in the marginal region and a central area with both areolae
and hltoportulae, or with areolae or fultoportulae only, into a new genus, Puncticulata Hikansson. This new genus comprises mainly the species that belonged to the Cyclotella bodanicdcomta complex (Hikansson 1988).
The last description of the genus Cyclotella (Kiitzing) Brkbisson 1838 nom. cons. Consid. Diatom. 19, with the generitype C. distinguenda Hustedt, was made by Hlkansson (2002). This genus is then characterised by a flat or tangentially undulated central area with or without valve face fultoportulae (“. . . None to several valve face fultoportulae are present . . .” opt. cit. Hlkansson 2002) and a striated marginal area with striae and interstriae of different width and length. Interstriae that continue onto the mantle terminate in the mantle hltoportulae, in the ring of which the rimoportula is located (see Hlkansson 2002). However, there are still many species that do not fit this current generic description, e.g. Cyclotella delicatula Hustedt, C. baicalensis Skvortzov et Meyer, C. minuta (Skvortzov) Antipova etc., and even several species formally transferred into this genus Cyclotella by Hlkansson (2002) do not match it, e.g. C. cyclopuncta Hikansson et Carter, C. cornensis Grunow, C. ocellutu Pantocsek, etc., all of them having rimoportula(e) on the valve face.
Among these species are the so-called “stelligeroid” taxa (Haworth & Hurley 1986), which comprise species with marginal fultoportulae and rimoportula(e) positioned between costae, but the external openings of rimoportula(e) are located nearer to the valve margin than the marginal hltoportulae. These and other unique features of this group have been subsequently discussed by more authors (Chang 1991, Houk 1992, Klee & Houk 1996, Hiibener 1999, Klee et al. 2000, Julius 2000, Hlkansson 2002, Alfinito & Tagliaventi 2002, Tagliaventi & Cavacini 2002). This complex currently encompasses 15 described species or lower taxa, which, not conforming to the original description of Cyclotella, deserve a formal transfer into a new genus, Discostella gen. nov.
MATERIAL AND METHODS
The study is based on comparison of data from the literature dealing with representatives of the genus Cyclotella, observations of the material Kryptogamae exsiccatae No. 2046, Nova Zeelandia: in lacu “Rotoaira” prope Taupo ca. 700 m. s. m., m. Jan., leg. S. Berggren from Botanische Staatssammlung Munchen (Germany) and the slide Coll. Deby B. M. 13035, C1. a. M. Diat. 300 from The Natural History Museum in London (U.K.). The original material No. 2046 of Grunow’s Diatom Collection in the Natural History Museum in Vienna (Austria) from the Lake Rotoaira taken by S. Berggren has not been found and no microscope slides directly attributable to this material are available. On the other hand, no material attributable to the slide Coll. Deby B. M. 13035, C1. a. M. Diat. 300 from The Natural History Museum in London (U.K.) is available.
Material containing “stelligeroid” taxa from various other localities were also observed. A Zeiss-Jena JENAVAL light microscope and a Hitachi S-3000 N scanning electron
microscope were used for observations.
Diagnosis
Order: THALASSIOSIRALES Glezer & Makarova 1986 Family: Stephanodiscaceae Glezer & Makarova 1986 Discostella Houk et Klee, gen. nov.
Cellulae vegetativae tympaniformes, solitariae vel in catenis. Valvae aspectu frontali circulares, cum superficie divisa in duas partes morphologiae distincte dissimilis. Area centralis plana vel concentrice undulata, structura stelliformi ex alveolis vel cristis extemis omata seu colliculata. Zona marginalis ex costis radialiter dispositis composita.
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 205
Fultoportulae marginales inter duas costas prope marginem valvae collocatae, interne duobus poris satelliticis lateraliter dispositis, externe aperturis subincrassatis vel tubis brevibus munitae. Rimoportula singularis, inter duas costas propius ad marginem valvae quam fultoportulae marginales inserta, interne cum labio brevi, externe cum apertura simplici circulari.
Cellulae primae lenticulares, in parte centrali laeves vel signo stelliformi ornatae et in parte marginali cum ordinatione valde simili eae in valvis cellularum vegetativarum, sed interdum cum pluribus rimoportulis.
Discostella differt a Cyclotella et Puncticulata collocatione fultoportularum marginalium et rimoportulae inter costas.
Vegetative cells drum-shaped, solitary or in chains. Valves circular or oval in valve view, valve face divided into two parts with distinctly different morphology. The central area flat or concentrically undulate, often with a star-shaped structure composed of alveoli or external ridges, or it is colliculate. The marginal area composed of radially arranged costae, marginal fultoportulae located between two costae, near the valve margin, internally with two satellite pores positioned laterally, externally with slightly thickened apertures or short tubes. One rimoportula situated between two costae, slightly nearer to the valve margin than the marginal fultoportulae, internally with a short labium, externally with a simple round opening.
The lenticular initial cells with the valve central part smooth or with a stellate pattern, the valve marginal part with similar pattern to the pattern of vegetative valves, but more rimoportulae can be present.
Discostella differs from all other cyclostephanoid genera in the location of the marginal fultoportulae and a rimoportula between costae.
Some species of this genus resemble each other in external SEM views of the valves, but differ in the internal valve ultrastructure, mainly in the marginal part. The following ultrastructure is especially important for the species differentiation:
alveoli - may be grooves (Figs 19, 20) or partially closed alveolar chambers (Figs 14-18), or open alveolar chambers (Fig. 21); costal branching - absent (Fig. 15), simple forking, or complex branching (Figs 19-21); marginal fultoportulae: internally on the valve margin (Figs 15, 16) or situated inside alveolar chambers (Fig. 14); without (Fig. 7) or with outer projections, tips of the tubes can be morphologically modified (Figs 3-6, 8-10); with (Fig. 17) or without (Fig. 19) a costa connecting internally the central tube with the valve margin; arranged irregularly (Fig. 15) or regularly (Fig. 3) , more dense (Fig. 16) or less dense (Fig. 21); the rimoportula - internally on the valve margin (Fig. 15) or within an alveolar chamber (Fig. 14); the pattern in the valve centre - may (Fig. 20) or may not have (Fig. 19) a stellate pattern.
Many taxa of the genus are heterovalvate. The convex valves often have stellate pattern of alveoli opening internally in the central part (Fig. 12), whereas the concave valves have a smooth internal centre (Fig. 13).
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Figs 1-10. Some external valve morphological variations in the genus Discostella. Figs 1-4. Central morphological variations of concave valve face. Fig. 1. Discostellu glornerutu. Fig. 2. D. sp. 1. Fig. 3. D. usterocostutu. Fig. 4. D. sp. 2. Figs 5-7. Central morphological variations of convex valve face. Fig. 5. D. sp. 2. Fig. 6. D. usterocostutu. Fig. 7 . D. stelligeru. Figs %lo. Morphological variations of a flat valve face. Fig. 8. D. sp. 3 . Fig. 9. D. pseudostelligeru. Fig. 10. D. woltereckii. Fig. 11. D. asterocostata. External opening of rimoportula (arrowed).
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Figs 12-21. Some internal valve variations in the genus Discosfella. Figs 12, 13. Valve heteromorphy in D. sfelligeru. Fig. 12. Convex central area with alveolate stellate pattern. Fig. 13. Smooth concave central area. Fig. 14. D. sfelligeru var. robusfa (corroded valve) with depressed marginal fultoportulae (arrowed) and rimoportula between two costae. Fig. 15. D. sfelligeru. Fig. 16. D. glomerufu with marginal fultoportulae between every costa. Fig. 17. D. usferocosfufu with each marginal fultoportula connected by a short costa to the valve edge (arrowed). Fig. 18. D. muscurenicu (corroded valve) with finger-like branching fine costae and marginal fultoportulae (arrowed) situated between two neighbouring costae. Fig. 19. D. wolfereckii with branched costae and a small central area. Fig. 20. D. woltereckii with an alveolate central area. Fig. 21. D. sp. 3 with branching costae and opened alveoli. Fig. 14 provided by Dr Paolo Cavacini (Universiti degli Studi di Roma, Italy) and used with his kind approval.
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Typus generis: Discostella stelligera (Cleve et Grunow) Houk et Klee, comb. nov.
Discostella stelligera (Cleve et Grunow) Houk et Klee, comb. nov. Basionym: Cyclotella meneghiniana var. ? stelligera Cleve et Grunow in Cleve 1881,
Kongliga Svenska Vetenskaps-Akademiens Handlingar. 18 (5), p. 22, PI. V, Fig. 63 a. Synonyms: Cyclotella rneneghiniana var. stellulifera Grunow (in Cleve) 188 1,
p. 22, P1. V, Fig. 63 b; Cyclotella stelligera Cleve et Grunow (in Van Heurck) 1882, P1. 94, Figs 22-26; Cyclotella meneghiniana var. ? stellifera Grunow (in Van Heurck) 1882, P1. 94,
Fig. 21, non Cyclotella stelligera var. Cleve et Grunow (in Van Heurck) 1882, PI. 94, Fig. 27.
Holotype: Kryptogamae exsiccatae No. 2046, Nova Zeelandia: in lacu “Rotoaira” prope Taupo ca. 700 m. s. m., m. Jan., leg. S. Berggren, Botanische Staatssammlung Munchen, Germany.
Zconotype: P1. 5, Fig. 63 a by Cleve et Grunow (in Cleve) 188 1. A slide prepared from type material:
Slide ZU4/100, Friedrich Hustedt Collection. Alfred-Wegener-Institut fiir Polar- und Meeresforschung, Bremerhaven, Germany.
Type locality: Lake Rotoaira, south of the Lake Taupo, New Zealand.
Fig. 22. a-f. Figures taken from Grunow’s notebook at the Museum Hist. Natur. Vindobonensis and from the literature. a, b. Figures and comments in Grunow‘s notebook. a. “Cycl. Meneghinianu var.? stelligera CI. & Gr., Neu Seeland, Rotoaira Lake”. The same figure was published by Cleve & Grunow (in Cleve 1881) in PI. 5, Fig. 63 a. b. Unpublished Grunow drawing with comment: “Cleve & Moeller 300, Neu Seeland, Taupo Lake”. c, d. Figures by Grunow in Van Heurck 1880-1885 with personal comments of Grunow. c. PI. 94, Fig. 27 “Cleve & Moeller 300, Taupo See, Neu Seeland”. d. PI. 94, Fig. 21 “2677 Gerardmer, C. rneneghiniana var.? stellifera”. e, f. Figures by Grunow in Cleve (1881), e. PI. 5, Fig. 63 b as variety stellulifera GRUNOW and f. PI. 5, Fig 63 c a small specimen of Cyclotella meneghiniana var.? stelligera from Lac de Gerardmer (Vosges).
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 209
Figs 23-30. LM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material. Valve views of the valves with the convex central area. Different central area patterns and only short occlusions of alveoli. Figs 23, 25,26, 30. Valve outside views and foci. Figs 24, 27-29. Valve inside views and foci. Figs 27, 29. Rimoportulae mowed.
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210 V. HOUK & R. KLEE
Figs 31-36. LM. Discostella stelligeru, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material. Central area of convex valves. Different central area patterns and only short occlusions of alveoli. Fig. 31. Rimoportula arrowed.
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 2 11
Figs 3745. L M . Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material. Figs 3744. Central areas of concave valves with ghost stellate pattern. Fig. 45. Cross-section focus.
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Figs 4651. SEM. Discostella steZZigera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Exterior valve views with convex central area.
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 213
Figs 52-57. SEM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Interior valve views with convex central area. Note different IengtWwidth ratio of the alveolar openings and different central stellate patterns in the central area.
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Figs 58-63. SEM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Valve interior details. Figs 58-62. Marginal fultoportulae (white arrows) with two laterally positioned satellite pori and rimoportula (rp) with a short labium, both situated between costae. Fig. 63. Detail of the central alveolate stellate pattern.
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 215
Figs 64-69. SEM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Exterior valve views with concave central area. Note colliculate central area (Figs 64,65) or central area with the stellate pattern composed of external ribs (Figs 66-69).
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Figs 70-75. SEM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Exterior valve views with concave central area. Note colliculate central area (Fig. 70) or the central area with the stellate pattern composed of external ribs (Figs 71-75).
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Figs 76-81. SEM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Interior valve views with smooth concave central area. Figs 76, 78-81. Marginal fultoportulae (white arrows) with two laterally positioned satellite pori and rimoportulae (rp) with a short labium, both situated between costae. Fig. 77. A valve with the valvocopula.
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Figs 82-93. SEM. Discostella stelligera, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Figs 82-84. Exterior valve views ~ details of the concave central area. Figs 85-90. Exterior valve views - details of the convex central area. Figs 91-93. Interior valve views - details of different alveolate stellate patterns of convex central area.
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Figs 94-99. SEM. Discostella stelligeva, Lake Rotoaira, New Zealand, Kryptogamae exsiccatae No. 2046 (Museum Hist. Natur. Vindobonensis), slide prepared from type material; scale bars in pm. Details of exterior valve margin. Outer openings of the marginal fultoportulae arrowed; note areolated outer layer of alveoli between radiating external ribs.Fig. 99. rp = rimoportula.
Vegetative cells cylindrical and solitary, frustules can be heterovalvate. Valves circular, 5 4 0 pm in diameter. The central area is distinctly convex or concave. The convex central areas always with a star-shaped structure composed of circular to elongated alveoli, opened to the valve inside and with areolate outer layer (Figs 85-93); sometimes smaller circular alveoli can be inserted between them (Figs 28, 89, 91). One distinct circular alveolus may be present in the hyaline valve centre (Figs 28,29,33,34, 85,91). The concave central areas always lack alveolae (Figs 76-8 l), have an ill-defined stellate pattern externally consisting of radially arranged costae;
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the rest is more or less colliculate, depending on the valve size and silicification (Figs 64-75, Figs 82-84). The striate marginal area creates a regular ring structure, sharply separated from the central area, with the width to ' / 5 of the valve radius. The marginal area is composed of radially arranged thick costae. The marginal fultoportulae are situated between costae near the valve margin, between each 1-4 alveolae; internally the marginal fultoportulae are of the type drawn by Theriot & Serieyssol(l994, Fig. 3 E), having two satellite pores positioned laterally, with cowling and relatively short internal extensions of the central tubes (Figs 5842). Externally there are slightly thickened apertures (Figs 94-99). The striae density is between 8.9 and 1 1.5 striae in 10 pm. Valves of vegetative cells always with only one rimoportula occurring at the valve edge between two costae, internally with a sessile labium in the ring of marginal fultoportulae, the direction of the slit is radial or oblique (Figs 58,60, 61, 62); externally with a simple pore between two costae in the ring of marginal fultoportulae (Fig. 99).
Nomenclatural changes
New nomenclatural combinations proposed in connection with the introduction of the new genus Discostella:
Discostella asterocostata (Lin, Xie et Cai) Houk et Klee, comb. nov. (Figs 127,128) Basionym: Cyclotella asterocostata Lin, Xie et Cai (in Xie, Lin et Cai 1985). Acta
Syntype localities: Miyan Reservoir in Beijing, China; Tangshan in Hebei, China; Shanyang in Phytotaxonomica Sinica 23 (6), p. 473, P1. 1, Figs 1-6.
Liaoning, China; Suzhou in Jiangsu, China; Guilin in Guangxi, China.
Discostella asterocostata var. striata (Chen) Houk et Klee, comb. nov. Basionym: Cyclotella asterocostata var. striata Chen (1 987). Acta Hydrobiologica Sinica 11
Syntype localities: Xiancheng Xian in Sichuan Sheng, China; Deqin Xian in Yunnan Sheng, (4), Fig. 1.
China.
Discostella elentarii (Alfinito et Tagliaventi) Houk et Nee, comb. nov. (Fig. 115) Basionym: Cyclotella elentarii Alfinito et Tagliaventi (2002). Algological Studies 105, p. 33,
Type locality: Lake Monowai, South Island, New Zealand. Figs 1-10, 12-25.
Discostella glomerata (Bachmann) Houk et Klee, comb. nov. (Fig. 114) Basionym: Cyclotella glomerata Bachmann (1 91 1). Das Phytoplankton des Sujlwassers mit
Type locality: Zugersee, Switzerland. besonderer Beriichichtigung des Vierwaldstattersees, p. 13 1, Figs 106-1 08.
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 221
Figs 100-118. Species belonging into the genus Discostella. Figs 100-105, 107-113, 115-117. LM; 10 pm scale bar. Figs 106, 114, 118. SEM; scale bars in pm. Figs 100, 101. Discostella sp. 1. A lake in Brazil. Figs 102-104. D. sp. 2. Mountain lake Nizne Temnosmrecinske, Slovakia. Fig. 105. D. sp. 3. River Vltava, Czech Rep. Fig. 106. D. sp. 4. Fossil, Chile. Figs 107,108. D. tasmanica. Cleve et Moller, slide No. 300, Lake Taupo, New Zealand. Figs 109, 110. D. pseudostelligera. Type material, Coll. Hustedt E 528, Ems River, Germany. Figs 111, 112. D. stelligeroides. Type material, Coll. Hustedt E 761, Plitvicer Seengebiet, Croatia. Fig. 113. D. areolata. Fossil, Holotypus, Coll. Hustedt Ac1/64, Lake Toba, Sumatra. Fig. 114. D. glornerata. Coll. Hustedt E 1103, Bodensee. Fig. 115. D. elentarii. Lake Monowai, New Zealand. Figs 116118. D. mascarenica. Lake Mare 9 Poule d’Eau, Rkunion. Figs 113 and 11 5 were provided by Dr Silvia Alfinito (Universiti degli Studi di Roma, Italy) and used with her kind approval.
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222 V.HOUK & R.KLEE
Figs 119-128. Species belonging into the genus Discostellu. Figs 119, 121, 123-126. LM; 10 pm scale bar. Figs 120, 122. SEM; scale bar = 5 pm. Figs 119-122. Discostellu woltereckii. Type material, Coll. Hustedt As 1329, A small pond in Buitenzorg, Java. Fig. 123. D. stelligeru var. hyulinu. Fossil, Holotypus, Coll. Hustedt Ac1/63, Lake Toba, Sumatra. Figs 124-125. D. pliostelligera. Fossil, Japan. Fig. 123. D. stelligeru var. robustu. Fossil, Lectotypus, Coll. Hustedt Ac1/63, Lake Toba, Sumatra. Figs 127, 128. D. usteerocostutu. River Haihe, east China. Figs 123 and 126 were provided by Dr Silvia Alfinito (UniversitB degli Studi di Roma, Italy) and used with her kind approval. Figs 124 and 125 were provided by Dr Hiroyuki Tanaka (Chuoh Senior High School, Shinbotanaka, Gunma, Japan) and used with his kind approval.
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 223
DiscosteZZa mascarenica (Klee, Houk et Bielsa) Houk et Klee, comb. nov. (Figs 116-118) Basionym: Cyclotella mascarenica Klee, Houk et Bielsa (2000). Algological Studies 98, p. 9,
Type locality: Mare a Poule d’Eau, Reunion (France) Figs 34,35,44,45, 56,57,68,74.
Discostella pliostelligera (Tanaka et Nagumo) Houk et Klee, comb.nov. (Figs 124,125) Basionym: Cyclotella pliostelligera Tanaka et Nagumo (2002). In: Proceedings of the 15th
International Diatom Symposium, The Netherlands 1998, (J. John, ed.), p.356, Figs 2- 10,p. 357,Figs 11-13,p. 358, 17, 18.
Type locality: Tazawa-ko (Lake Tazawa), Japan
DiscosteZZapseudosteZZigera (Hustedt) Houk et Klee, comb. nov. (Figs 109,110) Basionym: Cyclotella pseudostelligera Hustedt ( 1939). Abhhandlungen des Naturwissen-
Type locality: Ems, bei Papenburg. 197, Germany. schaftlichen Vereins Bremen 31, p. 591, Figs 1,2.
Discostella stelligera var. hyalina (Hustedt) Houk et Klee, comb. nov. (Fig. 123) Basionym: Cyclotella stelligera var. hyalina Hustedt (1935). Archiv fur Hydrobiologie,
Type locality: Tobasee, Sumatra. Supplement 14, p. 147, Fig. 5.
Discostella stelligera var. robusta (Hustedt) Houk et Wee, comb. nov. (Fig. 126) Basionym: Cyclotella stelligera var. robusta Hustedt (1 935). Archiv fir Hydrobiologie,
Type locality: Tobasee, Sumatra. Supplement 14, p. 147, pl. 9, Fig. 4.
Discostella stelligera var. tenuis (Hustedt) Houk et Klee, comb. nov. Basionym: Cyclotella stelligera var. tenuis Hustedt (1 937). Archiv @r Hydrobiologie,
Supplement 15, p. 143, pl. 9, Fig. 5. Type locality: Sindanglaja, Stausee, Java.
Discostella stelligeroides (Hustedt) Houk et Klee, comb. nov. (Figs 111,112) Basionym: Cyclotella stelligeroides Hustedt (1 945). Archiv f i r Hydrobiologie 40, p. 899,
Type locality: Plitvicer Seengebiet, Croatia. pl. 42, Figs 68,69.
Discostella tasmanica (Haworth et Tyler) Houk et Klee, comb. nov. (Figs 107,108) Basionym: Cyclotella tasmanica Haworth et Tyler (1993). Hydrobiologia 2691270, p. 54,
Type locality: Lake Laura, Tasmania. Figs 2-28.
Discostella woltereckii (Hustedt) Houk et Nee, comb. nov. (Figs 119-122) Basionym: Cyclotella woltereckii Hustedt (1 942). Internationale Revue der gesamten
Hydrobiologie. 42, p. 16, Figs 11-13. Type locality: Buitenzorg, Teich. 98, Java.
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224 V. HOUK & R. KLEE
DISCUSSION
Discostella differs from Cyclotella and Puncticulata in an unique combination of characters, having marginal fultoportulae and a rimoportula located between costae, with the rimoportula inserted in the ring of marginal fultoportulae, and possess neither areolae nor fultoportulae in the central area.
Discoplaea graeca y stelligera, illustrated but never described by Ehrenberg (1 854) as one of two varieties of his Discoplaea? graeca Ehrenberg 1841 from the fossil material from Morea (Greece), is probably the first mention of a stelligeroid taxon (see Hgkansson 1986). However, when Hikansson ( 1986) investigated the original Ehrenberg material of the Discoplea species, she was unsure of the taxonomic position of this variety because the ornamentation of the valve face on Ehrenberg’s (1 841) drawings resemble Cyclotella stelligera Cleve & Grunow, but could also correspond to another of the species found in the material from Ehrenberg’s collection. Therefore, the first described and illustrated ‘stelligeroid’ taxa are Cyclotella meneghiniana var.? stelligera Cleve et Grunow (in Cleve) 188 1, p. 22, P1. V, Fig. 63 a and Cyclotella meneghiniana var. stellulifera Grunow (in Cleve) 1881, p. 22, P1. V, Fig. 63 b. Unfortunately the name of the locality from New Zealand, “Rotorua Lake, coll. by S. Berggren” (Cleve et Grunow in Cleve 1881, p. 22), is most likely incorrect, because “Nova Zeelandia: in lacu “Rotoaira” prope Taupo ca. 700 m. s. m., m. Jan. leg. S. Berggren” is quoted in the protologue of this material (see Fig. 129), Kryptogamae exsiccatae Nr. 2046 (Zahlbruckner, A. (1900-1923), Museum Hist. Natur. Vindo- bonensis).The mistake probably arose from incorrect reading of Grunow’s handwriting (see
KQptog mae exsiccatae.
2046. Cyclo ttlla atclligera. /c C l w e st Grunow apud Clove, Ua some new or little known Diatoms [ZSSI), p. zz,
Tab. 5, Fig. 63 a, r ; Van Honr:k, Synops, Diatom., Tub. 94, Fig. a2--17; Da Toni, Sy& Algar., vat. 11 (r8gx), p. 1355.
Nova ZdanQia: in ltcu rRotoairrb prope Tuupo ca, 700 m. s. m., m. Jon, 1.6. S. B a r g ~ r s n , dot. F. Nurrtedt.
Fig. 129. A copy of the protologue to the material Nr. 2046 (Botanische Staatssammlung Miinchen).
Fig. 22a) at the publisher and it is repeated by subsequent authors when Cleve & Grunow 1881 is quoted (e.g. Haworth 1983). One year later Cleve and Grunow (in Van Heurck 1882, P1. 94, Figs 22-26) published drawings of a new species, Cyclotella stelligera, without any description, and never mentioned C. meneghiniana var. stelligera or C. meneghiniana var. stellulifera. Lac de Gerardmer (France) is given as the type locality of C. stelligera. In their Fig. 27 (Cleve and Grunow in Van Heurck 1882, P1. 94) a variety of C. stelligera is illustrated and “Lac Tampa, Nouvelle ZClande” is quoted as the locality. Unfortunately, this is incorrect and should be: “Lac Taupo, Nouvelle ZClande”. Again, almost certainly this mistake was due to incorrect reading of Grunow’s handwriting (see Fig. 22b, c). Adding to the confusion, Haworth and Hurley (1986, p. 47) alleged that “type material from Rotorua (Cleve & Moller, slide no. 300) confirmed identification of C. stelligera”. However it is clear from Grunow’s comments to his drawings of diatoms from the Cleve & Moller slide no. 300 (see Fig. 22b, c) that the material in this slide is from Lake Taupo. However, the type locality for Cyclotella meneghiniana var.? stelligera Cleve et Grunow (in Cleve) 188 1 and Cyclotella meneghiniana
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THE STELLIGEROID TAXA OF THE GENUS CYCLOTELLA 225
var. stellulifeu Grunow (in Cleve) 188 1 is Lake Rotoaira (Fig. 130), while Lake Taupo is the locality for the Cleve & Moller slide no. 300. In accordance with these findings we observed different diatom communities in the material from the two lakes. While Aulucoseiru species prevail in the Cleve & Moller slide no. 300, Frugilaria species prevail in the material from Lake Rotoaira. It is also interesting that we found Discostella cf. tusmanica as frequent as D. stelligera in the Cleve & Moller slide no. 300 (see Figs 131-136).
Fig. 130. Lake Rotoaira, viewed from top of Mt Tongariro. South end of Lake Taupo in background (the picture and text borrowed from http://homepages.ihug.co.nz/).
ACKNOWLEDGEMENTS
We wish to thank Dr Dagmar Triebel (Botanische Staatssammlung Munchen), Dr Geraldine Reid (The Natural History Museum, London) and Friedel Hinz (Alfred- Wegener-Institut f i r Polar-und Meeresforschung, Bremerhaven) for their kind help with material. We would like to thank very much to Dr Petr Marvan (Botanical Institute, Czech Academy of Sciences, Trebonboii) for the Latin diagnosis and the suggestion of the genus name, and Dr Richard Crawford (Alfred-Wegener-Institut f i r Polar-und Meeresforschung, Bremerhaven) for his critical comments and correcting the language.
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