Heteroscytonema crispum (Bornet ex De Toni) G.B. McGregor & Sendall (2018: 15)

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

Heteroscytonema crispum (Bornet ex De Toni) G.B. McGregor & Sendall (2018: 15) Fig. 73 A–F .

Basionym: Scytonema crispum (Bornet ex De Toni 1907: 498)

Filaments solitary or many together forming a caespitose, woolly thallus, olive-green to blackish green in colour. Filaments straight to variously flexuous, sometimes slightly coiled, 18–25 (–35) μm wide, cylindrical, with solitary or geminate false-branching; sheath firm, lamellated, with a smooth exterior surface, colourless or slightly yellowish-brown in mature filaments. Trichome the same width along the entire length, not or slightly constricted at the cross walls. Vegetative cells discoid to short barrel-shaped, 3.5–10.5 (–15) μm long × (12–) 16.5–25.0 (–30) μm wide; terminal cells widely rounded. Heterocytes discoid to subspherical, single or up to two in series, 9.0–20.5 (–37) μm long × 12.5–18.9 (–26) μm wide.

Specimens examined:—Awoonga Dam, Pool Ck at Talaroo, Fat Hen Ck at Kilkivan, Brisbane R. at Colleges Crossing, Brisbane R. at Savages Crossing, Emu Ck at Grieves Rd, Little Yabba Ck Maleny–Kenilworth Rd Crossing, Marongi Ck at Turtle Ck Rd, Reedy Ck at Mt. Byron Rd, Sandy Ck at Wivenhoe-Somerset Rd Crossing, Sheepstation Ck at Kilcoy-Murgon Rd, Wallaby Ck at Himstedts Rd.

Other records:— Queensland: Enoggera Res., Brisbane, A.B. Cribb, 1962 (BRI 0703039), Nandinya Falls, Palmerston Natl Park, A.B. Cribb, 1973 (BRI 0703040), Stony Ck, Wallaman Falls Natl Park, A.B. Cribb, 1972 (BRI 0703041), Canarvon Ck, Canarvon Gorge, A.B. Cribb, 1979 (BRI 0703042), Ipswich,A.B. Cribb, 1949 (BRI 0703046), Bailey (1913); New South Wales: South of Goathouse, c. 300 m down northern catchment of Dinner Run, Skinner, 2000 (NSW 448452); Western Australia: Dubaut Ck, Shark Bay, Huisman, 2009 (PERTH 8578451). Other records as S. cinncinnatum : Queensland: Mt Catharina, 10 km NE of Ingham, Skinner, 1984 (CANB 543263), Murray Falls, Murray R., 25 km NW of Cardwell, Entwisle, 993 (MEL); New South Wales: Coombadjha Ck, Washpool Natl Park, Skinner, 2000 (NSW), McCarrs Ck, Ku-Ring-Gai Chase Natl Park, Entwisle, 1999 (NSW), Waratah Gully Ck, 750 m E of Berowra Rly Stn, Entwisle, 2000 (NSW), Bridal Veil Falls, Govetts Leap, Blackheath, Entwisle, 1999 (NSW), Endrick R., 4 km NE of Nerriga, Entwisle, 1991 (NSW); Northern Territory: The Rocks Waterhole, Kakadu Natl Park, Entwisle, 1997 (MEL), Florence Falls, Litchfield Natl Park, Entwisle, 1997 (MEL), Walker Ck, Litchfield Natl Park, Entwisle, 1997 (MEL).

Observations:—Widespread and common species, known from riverine habitats throughout Australia. Considered synonymous with S. cincinnatum Thuret ex Bornet & Flahault. Strains from Australia, New Zealand, and Europe are known to produce saxitoxins, otherwise known as paralytic shellfish poisons (PSPs) ( Sendall & McGregor 2018, Smith et al. 2011).

SCYTONEMA

Figures

FIGURE 73. A–F Heteroscytonema crispum. Scale bars A–D, F = 20 μm, E = 50 μm