Calothrix sp. C

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

Calothrix sp. C Fig. 60 B–I .

Filaments endogloeic in the mucilage of benthic colonial cyanobacteria, solitary or in irregular clusters, occasionally with single false-branching, up to 300 μm long, gradually tapering towards the ends, not or slightly constricted at the cross walls. Sheath fine, hyaline, colourless. Vegetative cells at the base isodiametric or up to 2.5 × longer than broad, 2.5–8.3 μm long × 2.0–6.5 μm wide, pale blue-green in colour; apical cells conically rounded. Heterocytes basal or intercalary; basal heterocytes spherical to conical, 3.0–6.0 μm long × 3.0–5.5 μm wide; intercalary heterocytes barrel-shaped, 4.5–7.0 μm long × 3.0–4.0 μm wide. Intercalary heterocytes may form in pairs, becoming terminal following breakage, or solitary giving rise to single false-branching or hormogonia. Akinetes not observed.

Specimens observed:—Yowah Spring #4.

Observations:—Epigloeic, growing within the mucilage of Aphanocapsa colonies in a shallow Great Artesian Basin spring. Similarities with species from Calochaete and Roholtiella .

Figures

FIGURE 60. A Fortiea sp. A; B–I Calothrix sp. C; J–K Microchaete sp. A. Scale bars = 20 μm