| Texto completo | |
| Autor(es): |
Santana, Julio Cesar de O.
;
Calcagnotto, Daniela
;
Quagio-Grassiotto, Irani
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Neotropical Ichthyology; v. 12, n. 2, p. 9-pg., 2014-04-01. |
| Resumo | |
Spermiogenesis and spermatozoa in six genera of the African family Alestidae plus the Neotropical genus Chalceus are 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 acutidens and Rhabdalestes rhodesiensis. Spermatozoa morphology varies from a medial nucleus with fibrillar chromatin in the most basal genus Brycinus to a strongly eccentric nucleus with highly condensed chromatin in the more derived Rhabdalestes and Micralestes. Chalceus has a very similar spermatozoon to that found in Brycinus sharing 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. (AU) | |
| Processo FAPESP: | 10/01626-2 - Análise das características ultraestruturais da espermiogênese e dos espermatozoides de representantes da superfamília Erythrinoidea (Teleostei: Characiformes): uma abordagem filogenética |
| Beneficiário: | Júlio César de Oliveira Santana |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |