Comparative description and discussion of spermiogenesis and spermatozoal ultrastructure in some species of Heptapteridae and Pseudopimelodidae (Teleostei: Siluriformes)
Quagio-Grassiotto, Irani
Spadella, Maria Angélica
Carvalho, Márcio de
Oliveira, Claudio
Neotropical Ichthyology
2005
2005-09-30
3
3
401
410
6254S
337659
Bockmann
1998
[158,322,418,441]
Actinopterygii
Heptapteridae
Animalia
Siluriformes
2
403
Chordata
family
Heptapteridaespermatozoa.In the Heptapteridaespermatozoa, the head is formed by the nucleus that does not shows a nuclear fossa. The nucleus is surrounded by a narrow strip of cytoplasm with no organelles. The nucleus is occupied by highly condensed homogeneous chromatin and displays some electron-lucent areas ( Figs. 5A-B, 6A-B). R. quelenspermatozoa have an ovoid head with an ovoid nucleus ( Fig. 5A), while in P. gracilis,the head and the nucleus are round ( Fig. 6A). The centriolar complex remains close to the nucleus and is surrounded by a thin layer of electron-dense material ( Figs. 5A, 5E, 5F, 6A, 6E). In R. quelen,the proximal centriole is anterior, lateral and perpendicular to the flagellum basal body - the differentiated distal centriole ( Figs. 5E-F), while in P.membranous loops at the midpiece end ( Figs. 5E, 6E). The single tail or flagellum contains the classical axoneme (9+2), and the flagellar membrane does not form lateral fins ( Figs. 5C-D, 6H).