Dolichospermum affine (Lemmermann) Wacklin, Hoffmann & Komárek (2009: 61)

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

Dolichospermum affine (Lemmermann) Wacklin, Hoffmann & Komárek (2009: 61) Fig. 9 A–D.

Basionym: Anabaena affinis Lemmermann (1897: 261)

Filaments solitary, planktonic; trichomes straight or slightly flexuous, constricted at the cross walls, not attenuated towards the ends; mucilage fine, colourless, up to 20 μm wide. Vegetative cells spherical or slightly barrel-shaped, compressed at the poles, clearly constricted at the cross walls, (2.5–) 4.5–7.5 μm long × 4.5–6.0 μm broad, with aerotopes; apical cells rounded to shortly conical. Heterocytes intercalary, solitary, spherical, 5.0–7.5 μm in diameter. Akinetes intercalary, solitary or rarely in pairs, ovate to oblong with rounded ends, adjacent to or remote from the heterocytes, (6–) 11–22 (–30) μm long × (4.5–) 9.0 – 13.0 μm broad.

Specimens examined:—Atkinson Dam, Bill Gunn Dam, Burnett R., Ned Churchward Weir.

Other records:— South Australia: Warren Res., Strathalbyn Res., Mount Lofty Ranges, Baker (1991), Ling & Tyler (2000); Victoria: Baker & Fabbro (2002).

Observations:—A widespread species, recorded throughout Europe, Asia, North and South America and New Zealand (as Anabaena affinis Lemmermann ). Australian populations are not known to form fascicles of parallel arranged trichomes as variously reported from Europe.

Dolichospermum circinale (Rabenhorst ex Bornet & Flahault) Wacklin, Hoffmann & Komárek (2009: 61) Fig. 10 A–C.

Basionym: Anabaena circinalis Rabenhorst ex Bornet & Flahault (1886: 230)

Filaments solitary or entangled into small clusters, planktonic; trichomes circinate or irregularly open screw-like coiled,> 50 μm in diameter, constricted at the cross walls, not attenuated towards the ends; often associated with a broad, colourless mucilage. Vegetative cells spherical or compressed at the poles, blue-green in colour, with aerotopes, 7.0–8.5 (–11.0) μm in diameter; apical cells undifferentiated. Heterocytes spherical, 8.5–11.0 μm in diameter. Akinetes intercalary, solitary or in series, cylindrical, slightly curved and remote from the heterocytes, 20.0–28.0 μm long × 11.5–16.0 μm broad.

Specimens examined:—Atkinson Dam, Baroon Pocket Dam, Beardmore Dam, Fitzroy R. at Bedford Weir, Fitzroy R. at Bingegang Weir, Fitzroy R. at Eden Bann Weir, Fitzroy R. at Glebe Weir, Fitzroy R. at Moura Weir, Fitzroy R. at Neville Hewitt Weir, Fitzroy R. at Tartrus Weir, Fitzroy R. at Theodore Weir, Burnett R. at Ben Anderson Barrage, Burnett R. at Kirar Weir, Burnett R. at Ned Churchward Weir, Bill Gunn Dam, Bjelke-Petersen Dam, Bowen R. at Bowen R. Weir, Callide Dam, Cania Dam, Condamine R. at Jack Taylor Weir, Condamine R. at Chinchilla Weir, Burnett R. at Claude Wharton Weir, Coolmunda Dam, Crookes Dam, Pioneer R. at Dumbleton Weir, Pioneer R. at Mirani Weir, Eungella Dam, Fairbairn Dam, Glen Niven Dam, Glenlyon Dam, Kinchant Dam, Lake Clarendon, Lake MacDonald, Leslie Dam, Maroon Dam, Mary R. at Mary R. Barrage, Moogerah Dam, Moura offstream storage, Paradise Dam, Peter Faust Dam, Six Mile Ck at Bajool Weir, Teemburra Dam, Wuruma Dam, Wivenhoe Dam, Warrego R. at Allan Tannock Weir.

Other records:— New South Wales: Prospect Res., Cannon et al. (1970), Bowen & Smalls (1980), Lismore R., May (1970), Braidwood Lagoon, May (1972), Lake Uranagong near Finlay, May & McBarron (1973), Burrinjuck Dam, May (1978), Carcoar Dam, Glenbawn Dam, May (1981), River Murray at Torrumbarry and Euston, Sullivan et al. (1988), Chaffey Dam, May (1989), Baker (1991), Toonumbar Dam near Lismore, Baker (1991), Lake Cargelligo near Griffith, Baker (1991), Namoi R. near Walgett, Baker (1991), Hawkesbury R. at Sackville, Baker (1991); Western Australia: farm dams in south-west, Aplin (1983), Hyde Park, ( Lee et al. 2014); South Australia: Gumeracha Weir, R. Torrens, South Para Res., Hope Valley Res., Little Para Res., Happy Valley Res., Myponga Res., Hindmarsh Valley Res., Strathalbyn Res., Warren Res., Baker (1991); Victoria: Barkers Ck Res., Lake Cup Cup near Donald, Dock L. and Green L. near Horsham, Hepburn Lagoon near Ballarat, Hopetoun Res. near Warracknabeal, Kybram near Shepparton, Lance Ck Res. and Wonthaggi-Inverlock Res., Violet Town Res. near Benalla, Tallarook near Seymour, Baker (1991); Northern Territory: Kangaroo Ck, Humpage et al. (2013).

Observations:—Cosmopolitan species; known from every Australian state where it is a common bloom forming species in lakes, reservoirs, and farm dams. Australian populations can produce paralytic shellfish poisons (Humpage et al. 1994), and taste and odour compounds geosmin and 2-methylisoborneol ( Hayes & Burch 1989). It was the dominant species in a major bloom in the Barwon-Darling River in November and December 1991, which affected almost 1000 km of the system ( Bowling & Baker 1996).