Data/hora: 09/06/2024 02:46:20

Provedor de dados: | 83
País: | Brazil
Título: | Markiana nigripinnis (Perugia, 1891) as a putative member of the subfamily Stevardiinae (Characiformes: Characidae): spermatic evidence
Autores: | Baicere-Silva,Clarianna Martins; Benine,Ricardo C.; Quagio-Grassiotto,Irani.
Data: | 2011-06-01
Ano: | 2011
Palavras-chave: | Astyanax clade; Clade A; Spermiogenesis; Spermatozoa ultrastructure.
Resumo: | The genus Markiana was until recently recognized as incertae sedis in the family Characidae, even though alternative placements for this genus have been advanced since its original description. More recently, it was hypothesized that Markiana nigripinnis is part of a clade informally named the Astyanax clade, indicating the putative close relationship of Markiana with the genus Astyanax. Examination of sperm ultrastructure of representatives of Astyanax and M. nigripinnis shows no evidence for this hypothesized close relationship. Rather, the spermatozoa of M. nigripinnis share characters found in spermatozoa of the non-inseminating members of the subfamily Stevardiinae, such as an angle of nuclear rotation equal to 85º resulting in a lateral position of the double nuclear fossa and flagellum. As with the non-inseminating Stevardiinae, sperm nuclei are also slightly elongate toward the flagellum, the proximal centriole is partially inside the nuclear fossa and anterior and oblique to the distal centriole, and the midpiece is short and strongly asymmetric. Additionally, M. nigripinnis shares with the other members of the Stevardiinae the presence of only four teeth in the inner row of the premaxillary and a short triangular ectopterygoid, which is never more than twice the length of the palatine.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000200015
Editor: | Sociedade Brasileira de Ictiologia
Relação: | 10.1590/S1679-62252011005000020
Formato: | text/html
Fonte: | Neotropical Ichthyology  v.9 n.2 2011
Fonte: | info:eu-repo/semantics/openAccess