Cuspidothrix Rajaniemi, Komárek, Willame, Hrouzek, Kaštovská, Hoffmann & Sivonen (2005: 388)

Mcgregor, Glenn B., 2018, Freshwater Cyanobacteria of North-Eastern Australia: 3. Nostocales, Phytotaxa 359 (1), pp. 448-450 : 448-450

Cuspidothrix Rajaniemi, Komárek, Willame, Hrouzek, Kaštovská, Hoffmann & Sivonen (2005: 388)

Type: C. issatschenkoi (Usachev) Rajaniemi, Komárek, Willame, Hrouzek, Kaštovskà, Hoffmann & Sivonen (2005: 388)

Filaments planktonic; trichomes solitary, short to long, straight or curved, cylindrical, slightly constricted or unconstricted at cross walls, up to 6 μm wide, clearly narrowed and pointed at the ends. Vegetative cells cylindrical, isodiametric or longer than wide, cell content finely granular and/or with facultative aerotopes; apical cells elongated, attenuated and acuminate, mainly colourless and hyaline. Heterocytes intercalary, solitary, cylindrical or elliptical. Akinetes intercalary, solitary or rarely in twos, elongated ± cylindrical, remote from the heterocytes.

A widely distributed genus of five species known from the plankton of freshwater lakes, reservoirs and rivers. One species is known from north-eastern Australia. Bibliography: Baker (1991), Baker & Fabbro (2002), Rajaniemi et al. (2005a), Komárek & Komárková (2006), Komárek & Mareš (2012), Komárek (2016).

Cuspidothrix issatschenkoi (Usachev) Rajaniemi, Komárek, Willame, Hrouzek, Kaštovskà, Hoffmann & Sivonen (2005: 388) Fig. 8 A–E.

Basionym: Anabaena issatschenkoi Usachev (1938: 109)

Filaments planktonic; trichomes solitary or slightly flexuous, cylindrical, continually narrowed towards both ends, not or slightly constricted at the cross walls. Vegetative cells long cylindrical, with aerotopes, 4–8 (–15) μm long × 2.5–4.0 μm broad; apical cells narrowed, hair-like, often hyaline. Heterocytes solitary, sub-cylindrical 6–11 μm long × 2.5–4.0 μm broad. Akinetes cylindrical with rounded ends, solitary or in series, remote from the heterocytes, 6–20 μm long × 2.5–4.5 μm broad.

Specimens examined:—Condamine R. at Jack Taylor Weir, Warrego R. at Allan Tannock Weir, Atkinson Dam, Beardmore Dam, Fitzroy R. at Bedford Weir, Burnett R. at Ben Anderson Barrage, Burnett R. at Claude Wharton Weir, Burnett R. at Kirar Weir, Burnett R. at Ned Churchward Weir, Bill Gunn Dam, Fitzroy R. at Bingegang Weir, Fitzroy R. at Eden Bann Weir, Fitzroy R. at Glebe Weir, Fitzroy R. at Moura Weir, Fitzroy R. at Tartrus Weir, Fitzroy R. at Theodore Weir, Fitzroy R. at Neville Hewitt Weir, Bjelke-Petersen Dam, Boondooma Dam, Borumba Dam, Bowen R. at Bowen R. Weir, Kolan R. at Bucca Weir, Burdekin Falls Dam, Callide Dam, Cania Dam, Condamine R. at Chinchilla Weir, Coolmunda Dam, Pioneer R. at Dumbleton Weir, Pioneer R. at Marian Weir, Pioneer R. at Mirani Weir, Eungella Dam, Fairbairn Dam, Fred Haigh Dam, Gattonvalue offstream storage, Haughton R. at Giru Weir, Glenlyon Dam, Jones Weir, Julius Dam, Kinchant Dam, Lake Clarendon, Leslie Dam, Mary R. at. Mary R. Barrage, Moogerah Dam, Paradise Dam, Peter Faust Dam, Teemburra Dam, Tinaroo Falls Dam, Wuruma Dam.

Other records:— South Australia: Warren Res., Lake Alexandrina at Mannum, Lake Albert at Narrung, Campbell Park and Meningie, Baker (1991); New South Wales: River Murray at Lake Victoria, Baker (1991), Hume Dam, Humpage et al. (2013); Victoria: River Murray at Bonyaricall Ck, Baker (1991); Northern Territory: Ling & Tyler (2000).

Observations:—Common throughout the temperate zone including Europe, Asia, North America and New Zealand; recorded from lakes and reservoirs throughout eastern Australia.

DOLICHOSPERMUM