Water-borne Spores in Foam in a Subantarctic Stream System in Sweden

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1 Water-borne Spores in Foam in a Subantarctic Stream System in Sweden L. MABVANOVÄ Czechoslovak Collection of Microorganisms, J. E. Purkynö University, Tflda Obräncü miru 10, Brno, CSSK & A. MULLER-HAECKEL Department of Animal Ecology, University of Umeä, Sweden Summary. Spores of aquatic and water-borne hyphomycetes and other fungi were collected in foam samples in the Njakajokk stream system (Swedish Lapland) during the years 1975 and Forty-one different taxa were encountered (mainly aquatic hyphomycetes) 20 of which were known species. Nine species are new to Sweden; 21 are undescribed. Spores of the undescribed taxa are illustrated and accompanied by a few remarks on their occurrence and morphology. Introduction Spores of fungi foam samples have been reported from various parts of the world. It always appeared that the bulk of the spores were the conidia of so called aquatic and water-borne hyphomycetes in the sense of INGOLD (1975). In most cases the samples were only taken once a year and the results were probably influenced by the seasonal variation in species occurrence as well as abundance (IQBAL & WEBSTER, 1973; WILLOTIGHBY & ARCHER, 1973; GÖNCZÖL, 1975; LINDSEY & GLOVER, 1976; MÜLLER-HAECKEL & MARVANOVÄ, 1977; MÜLLER-HAECKEL, 1977). The number of previously described species of aquatic and waterborne hyphomycetes is about 140. About species have been reported from countries where intensive investigations have been carried out (RANZONI, 1953; TUBAKI, 1957; PETERSEN, 1962, 1963a and 1963b; MIURA, 1974; DUDKA, 1974; INGOLD, 1975). NILSSON (1964) recorded 39 species in Sweden. These data mainly concern geographical regions between N. Less is known from tropics and there are only a few reports concerning the subarctic region (NILSSON, 1958, 1964; KOBAYASI & al., 1967, 1971; DUDKA, 1972; MÄKELÄ, 1972; MÜLLER-HAECKEL & MARVANOVÄ, 1977, 1979). Methods The sampling of foam on a small stream Njakajokk (Fig. 1) near Abisko (Sweden, 68 21' N, 18 49' E) and its tributaries was carried 210

2 Verlag Ferdinand Berger & Söhne Ges.m.b.H., Horn, Austria, download unter out for two years from May 1975 to October 1976, provided that foam was present. Furthermore, conidia of water-borne and aquatic hyphomycetes in the same locality were caught on plexiglass slides (colonization) as well as strained from water samples (drift) (MÜLLER-HAECKEL & MARVANOVA, 1977, 1979). Eesults We found 41 species in the foam, 21 of them belonging to undescribed taxa. These are dealt with in the second part of this report where some remarks are also made on their distribution and morphology. The occurrence of the known species of aquatic hyphomycetes and other records from subarctic areas are listed in Table 1. Species new to Sweden are denoted by asterisk. In the Abisko material (Table 1: A, B) there is a difference between the spectrum of conidia collected in the foam and those obtained by colonization and drift, a circumstance that has been priviously noted by IQBAL & WEBSTER (1973) and LESTDSEY & GLOVEB (1976) and that has to be attributed to different selectivity of the various methods. A relatively low count of species recorded by other authors (except of DTTDKA, 1972) is probably due to scarce and illtimed sampling, which usually has been performed in summer, an unfavourable period for aquatic hyphomycete sporulation activity (IQBAL & WEBSTER, 1973, 1977; MÜLLEB-HAECKEL 1977; MÜLLER-HAECKEL & MARVANOVA, 1977, 1979; BÄRLOCHER & al., 1978). In the Kola-Karelian territory the sampling was also carried out in a less favourable month (August) but this shortcoming was counterbalanced by the diversity and amount of watersystems investigated (six streams and 11 rivers of 4 kinds; DUDKA, 1972). The occurrence of individual genera in the Abisko foam samples was different from that found in temperate regions. For example, the large genus Tricladium INGOLD is represented only by one species. It is also apparent that in the subarctic material nearly all species of the genus Lemonniera de WILD, are present, compared with only one species of Oyoerffyella KOL, an almost equally large and homogeneous genus. Noteworthy is also the occurrence of some species which are encountered only rarely in other parts of the world, e. g. Gyoerffyella gemellipara MARVANOVA, Lateriramulosa uniinßata MATSTTSHIMA, Pleuropedium tricladioides MARVANOVA & IQBAL, Taeniospora gradlis MARVANOVA. Lemmoniera pseudofloscula DYKO, described in 1977 from the Appalachian Mountains (USA), appeared in Abisko material very abundantly in autumnal samples of foam (Fig. 2A, B). DYKO in DESCALS, WEBSTER & DYKO (1977) gives the size of conidial elements as follows: Central body 4 7 fjt,m, arm length fxm, arm width 4 7 [im. Some of the Abisko specimens have longer and more slender arms (40 105x fim), and a smaller central body (3 6 fi.m). 14 * 211

3 Table 1. Occurrence of aquatic liyphomycete conidia in several subarctic localities Species Localities (T) terrestrial occurrence A B C D E F G Alatospora acuminata Anguillospora longissima Articulospora tetracladia Clavariopsis aquatica Clavatospora longibrachiata Clavatospora stellata Dimorphospora foliicola Flagellospora curvula Geniculospora inflata Oyoerffyella gemellipara Heliscus lugdunensis Lateriramulosa uniinflata Lemonniera aquatica Lemmoniera centrosphaera Lemonniera cornuta Lemonniera pseudofloscula Lemonniera terrestris Margaritispora aquatica Mycocenirospora acerina Mycocentrospora angulata Pleuropedium tricladioides Taeniospora gradlis Tetrachaetum elegans Tetracladium marchalianum Tricellula aquatica Tricellula aurantica Tricladium angulatum Tricladium gracile Tricladium splendens Varicosporium elodeae Volucrispora graminea x (T) x (T) (T) Localities: A Abisko: foam. B Abisko: colonisation and drift (MÜLLBB- HAECKEL & MARVANOVA, 1979). C Messaure (MÜLLER-HAECKEL & MARVANOVÄ, 1977). D Swedish Lapland (NILSSON, 1958, 1964). E Finnish Lapland (MÄKELÄ, 1972). F Kola-Karolian Northern Province of USSR (DTTDKA, 1972). G Alaska (KOBAYASI & al., 1967). H Greenland (KOBAYASI & al., 1971) There is also an unusual variability in the conidia of Margaritispora aquatica INGOLD (Fig. 3D), which show many transitional forms between the tetrahedral and irregularly tetradiate organisation. In our experience such intermediate shapes appear when the conidia are formed on the water surface. The remaining figures (Fig. 3 6) show the conidia and spores of undescribed taxa. 212

4 68 21'N 18 49'E ABISKO CHARA SJO 1km PAJEP NJAKAJAURE Fig. 1. The Njakajokk stream system 213

5 Fig. 3A. Lunulospora-resemblmg conidium, whose truncate base indicates that its way of attachment to the conidiogenous cell is quite different from that of Lunulospora INGOLD. Not every conidium has the conspicuous denticle on the concave side. Conidia of the same size and shape, but 7 11 septate were also abundant. Fig. 2. Lemonniera pseudofloscula: A. Phialides with young conidium. B. Mature conidia 214

6 50um Fig. 3. Conidia and spores from foam. Explanation in text Fig. 3B. Heliscus-like conidium, which cannot be identified with any described taxon. Fig. 3C. These conidia resemble those of Geniculospora inflata (LSTGOLD) NILSS. ex MAEVANOVÄ & NILSS., but are smaller and without septa in arms. 215

7 Fig. 4B. These conidia are probably identical with those reported bylngold (1968; Fig. 6 d) from Wales and by ARNOLD (1969; Fig. 5; 3) from U.S.S.R. DUDKA (1972; Fig. la) collected such a fungus in Kola- Karelian Northern Province of U.S.S.R. Tridentaria PREUSS may be the suitable genus. 216 Fig. 4. Conidia and spores from foam. Explanation in text

8 Fig. 4C. These conidia resemble those of the genus Tridentaria, but differ in successive growth and inequal size of arms. Fig. 4D. Probably a species of Flabellospora ALASOADUEA, but it does not match any described one. Fig. 4F. These conidia may be interpreted as aberrant ones of Tetracladium setigerum (GROVE) LNGOLD, but their occurrence in one locality in England (INGOLD, 1974) and one in Czechoslovakia Fig. 5. Conidia and spores from foam. Explanation in text 217

9 (MARVANOVÄ, unpublished) strongly suggests that a separate species is involved. Fig. 4G. Such conidia were seen by INGOLD (1968; Fig. (ib) in Wales. They belong to an undescribed genus. Fig. 4H. A wellknown organism from foam samples, whose development has recently been studied by WEBSTER & al. (1978), who consider it to be a member of the genus Entomophthora FRES. Fig. 41. Conidia of this species are very similar to those of Tetranacrium graminearum HUDSON & SUTTON (Sphaeropsidales) but this Fig. 6. Conidia and spores from foam. Explanation in text species is known from India and Jamaica only (HUDSON" & SUTTON, 1964). Fig. 4J. NILSSON (1958; Fig. 12e) reports a similar, but smaller conidium from Sweden. Taxonomic relationships are unknown. Fig. 5 A F. Filiform straight or sigmoid spores, whose taxonomic relations are difficult to recognize without having seen the mode of sporogenesis. The type A resembles a Fusarium, but it is longer than all known species with slender conidia. The type F has often been seen in Czechoslovakian highland streams and is reported by ARNOLD (1968) from GDR. Fig. 5G. Tetrachaetum sp. The conidium, though similar to that of Tetrachaetum elegans INGOLD, exceeds this twice in length of arms and the axis and has a denser septation. 218

10 Fig. 6A. A conidium of probably the same genus (Triposporina HÖHNEL) is known from Pakistan (IQBAL & al. 1973; Fig. 1H). Fig. 6B. This species may belong to the genus Dendrospora INGOLD. It has been collected in several mountain streams in Czechoslovakia (MABVANOVA, unpublished) and in England by INGOLD (1975). This relatively large amount of undescribed conidia together with the known taxa clearly illustrates that at least some subarctic freshwaters are much richer in species that are ecologically connected with aquatic environments,than could have been expected from earlier reports. These organisms can therefore be expected to play an important part in the angiosperm leaf degradation also under subarctic conditions. Acknowledgement The work was supported by the Swedish Natural Research Council and the Max Planck Gesellschaft. References ARNOLD, G. R. W. (1968). Sporen aquatischer Hyphomyzeten aus Gewässern im Bezirk Halle. Wissensch. Z. Friedrich-Schiller-Univ. Jena, math.- naturwiss. Reihe 17: (1969). Vodnye gifomitsety iz vodoemov leningradsjoj oblasti. Nov. Sist. nizh. Rast. 6: BÄRLOCHER, F., KENDRICK, B. & MICHAELIDES, J. (1978). Colonization and conditioning of Pinus resinosa needles by aquatic hyphomycetes. Arch. Hydrobiol. 81: DBSCALS, C. E., WEBSTER, J. & DYKO, B. S. (1977). Taxonomic studies on aquatic hyphomycetes. I. Lemonniera de WILDEMAN. Trans. Br. mycol. Soc. 69: DTJDKA, I. O. (1972). Vodnye gifomitsety v rekakh i ruchyach Kolsko-Karelskoj severo-taezhnoj provintsii. Mikol. Fitopatol. 6: (1974). Vodni hifomitseti Ukraini. Naukova Dumka, Kiiv. GÖNCZÖL, J. (1975). Ecological observations on the aquatic hyphomycetes of Hungary I. Acta bot. Acad. Sei. hungar. 21: & TÖTH, S. (1974). Rare or interesting conidia from streams in Hungary. Bot. Közlem. 61: HUDSON, H. J. & SUTTON, B. C. (1964). Trisulcosporium and Tetranacrium, two new genera of fungi imperfecti. Trans. Br. mycol. Soc. 47: INGOLD, C. T. (1958). New aquatic hyphomycetes: Lemonniera brachycladia, Anguillospora crassa, and Fluminispora ovalis. Trans. Br. mycol. Soc. 41: (1968). More spores from rivers and streams. Trans. Br. mycol. Soc. 51: (1974). Foam spora from Britain. Trans. Br. mycol. Soc. 63: (1975). An illustrated guide to aquatic and water-borne hyphomycetes. Freshwater biol. Ass., Sei. Publ. No 30. (1975). Conidia in the foam of two English stroams. Trans. Br. mycol. Soc. 65:

11 IQBAL,, S. H. & WEBSTER, J. (1973). Aquatic hyphomycote spora of the river Exe and its tributaries. Trans. Br. mycol. Soc. 61: and WEBSTER, J. (1977). Aquatic hyphomycete spora of some Dartmoor streams. Trans. Br. mycol. Soc. 69: , SULTANA, K. & FARZANA, S. (1973). Stream spora of Pakistan. Biologia 19: KOBAYASI, Y. & al. (1967). Mycological studies of the Alaskan arctic. Ann. Rep. Inst. Ferment. Osaka 3, 137 pp. (1971). Mycological studies of the Angmagssalik Region of Greenland. Bull. Nat. Sei. Mus. Tokyo 14 (1): LINDSEY, B. I. & GLOVER, B. J. (1976). Ecological studies of spores of aquatic hyphomycetos in the Cringle Brook, Lines. Hydrobiologia 51: MÄKELÄ, K. (1972). Some aquatic hyphomycetes on grasses in Finland. Karstenia 13: MIURA, K. (1974). Stream spora of Japan. Trans, mycol. Soc. Japan 15: MÜLLER-HAECKEL, A. (1977). Annual production of hyphomycete conidia in a subarctic stream. Oikos 29: & MABVANOVA, L. (1977). Konidienproduktion und -kolonisation von Süsswasser-Hyphomyceten im Kaltisjokk (Lappland). Bot. Notiser 129: (1979). Periodicity of aquatic hyphomycetes in the subarctic region. Trans. Br. mycol. Soc. 73: NELSSON, S. (1958). On some Swedish freshwater hyphomycetes. Svensk bot. Tidskr. 52: (1964). Freshwater hyphomycetes. Symb. bot. upsal. 18: PETERSEN, R. H. (1962). Aquatic hyphomycetes from North America. I. Aleuriosporae (Part 1) and key to the genera. Mycologia 54: (1963 a). Aquatic hyphomycetes from North America. II. Aleuriosporae (Part 2), and Blastosporao. Mycologia 55: (1963 b). Aquatic hyphomycetes from North America. III. Phialosporae and miscellaneous species. Mycologia 55: RANZONI, F. V. (1953). The aquatic hyphomycetes of California. Farlowia 4: TUBAKI, K. (1957). Studies on the Japanese hyphomycetes. III. Aquatic group. Bull. natn. Sei Mus. Tokyo 14: WEBSTER, J., SANDERS, P. F. & DESCALS, E. (1978). Tetraradiate aquatic propagules in two species of Entomophthora. Trans. Br. mycol. Soc. 70: WILLOUGHBY, L. G. & ARCHER, J. F. (1973). The fungal spora of a freshwater stream and its colonization on wood. Freshwat. Biol. 3: