Data/hora: 02/06/2024 02:41:18

Provedor de dados: | 83
País: | Brazil
Título: | Sperm evolution in the family Alestidae with comparative data for the genus Chalceus (Ostariophysi: Characiformes)
Autores: | Santana,Júlio César de O.; Calcagnotto,Daniela; Quagio-Grassiotto,Irani.
Data: | 2014-06-01
Ano: | 2014
Palavras-chave: | African Fish; Ostariophysi; Spermatozoa; Systematics; Ultrastructure.
Resumo: | Spermiogenesis and spermatozoa in six genera of the African family Alestidae plus the Neotropical genus Chalceusare described. Spermiogenesis is quite similar in all Alestidae and is identified as Type I and its variants. In Type I spermiogenesis, the flagellum of earliest spermatids lies lateral to the nucleus, and rotation of the nucleus towards the centriolar complex is observed. Nuclear rotation is complete reaching 90 degrees in Bryconalestes longipinnis, Brachypetersius altus, Brycinus imberi, B. lateralis, and Alestopetersius compressus; and is incomplete reaching 20 degrees in Micralestes acutidensand Rhabdalestesrhodesiensis. Spermatozoa morphology varies from a medial nucleus with fibrillar chromatin in the most basal genus Brycinusto a strongly eccentric nucleus with highly condensed chromatin in the more derived Rhabdalestesand Micralestes. Chalceushas a very similar spermatozoon to that found in Brycinussharing the fibrillar aspect of the chromatin in the nucleus. This feature is so far only observed in these two genera among African and Neotropical characiform fishes.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000200419
Editor: | Sociedade Brasileira de Ictiologia
Relação: | 10.1590/1982-0224-20130177
Formato: | text/html
Fonte: | Neotropical Ichthyology  v.12 n.2 2014
Fonte: | info:eu-repo/semantics/openAccess