Sperm ultrastructure in three different families of weakly electric fishes (Teleostei: Gymnotiformes)

Abstract

This study presents details of sperm ultrastructure for Gymnotus aff. carapo (Gymnotidae), Eigenmannia trilineata(Sternopygidae), and three Brachyhypopomus species (B. draco, B. bombilla, and B. gauderio - Hypopomidae) from southernBrazil. Differences were found among the representatives of the different families. For example, nuclear rotation was presentin E. trilineata and in the Brachyhypopomus species, but absent in Gymnotus aff. carapo, and the presence of flagellar finswas only observed in E. trilineata. Some intraspecific variations could also be noticed among the Brachyhypopomus speciesanalyzed. Most of the characters found in the spermatozoa of the species studied herein are shared with species of Gymnotiformes previously analyzed. © 2011 Sociedade Brasileira de Ictiologia.