FIGURE 4. A–D in Morphological diversity of benthic Nostocales (Cyanoprokaryota/Cyanobacteria) from the tropical rocky shores of Huatulco region, Oaxaca, México

FIGURE 4. A–D. Scytonematopsis cf. crustacea. A. Thallus with false branching. B. Thallus of isopolar attenuated filaments, basal and intercalary heterocytes. C. Isopolar crescent-shaped development of hormogonia. D. Isopolar hormogonia formation. E–H. Kyrtuthrix cf. maculans E. Isopolar and attenuated filaments in parallel series. F. Filaments within a firm sheath. G. Epilithic thallus with intercalary heterocytes. H. Cells pyramid-shaped, arrow pointing at heteropolar hormogonia formation. het = heterocyte, ihet = intercalary heterocyte, bhet = basal heterocyte. Scale bars: A = 30 μm, B–C = 20 μm, D–H = 6 μm.