Fig. 6 in Comparative analysis of spermiogenesis and sperm ultrastructure in Callichthyidae (Teleostei: Ostariophysi: Siluriformes)

Fig. 6. Spermatozoa of Aspidoras poecilus. a) Spermatozoon longitudinal section. b and c) Nucleus in longitudinal and cross sections. d) Centriolar arrangement. e to i) Midpiece in longitudinal and transverse sections showing mitochondria, vesicles, cytoplasmic channel, and electron-dense circular structures. j and k) Flagellum in longitudinal sections. j-inset and l) Flagellum in cross sections. (a, b, f, j, k) X 23000; (c, d) X 17000; (e) X 22050; (g, h) X 25200; (i) X 18400; (j-inset, l) X 57500. B: basal body; D: distal centriole; E: electron-dense structure; F: flagellum; N: nucleus; P: proximal centriole; V: vesicles; Asterisk: mitochondria, Arrow: cytoplasmic channel; Arrowhead: lateral membranous compartment; Double arrowhead: electron-dense material between the centrioles; Lozenge: electron-dense circular structure.