title: Comparative morphology of the reproductive system of seven species of ostariophysan fishes from the upper Das Velhas River, Brazil.
abstract: The success of fishes in different environments is related with the variation of reproductive strategies developed by the systematic group, which is reflected in the morphology of the reproductive system and can have ecological and evolutionary implications. This study comparatively analyzed the morphological characteristics of the male and female reproductive systems of ostariophysan fish species from the upper Das Velhas River in the São Francisco River basin, Brazil. In order to accomplish this, 393 specimens belonging to seven fish species were sampled between April 2010 and June 2015 for histological, ultrastructural, histochemical, and morphometric analyses. All the species examined have anastomosing tubular testes with unrestricted distribution of spermatogonia. Astyanax bimaculatus, A. fasciatus, A. scabripinnis, and Harttia torrenticola had their spermatozoa embedded in a glycoprotein secretion within the tubule lumen. Most species had type I spermiogenesis, whereas Rhamdia quelen had type III spermiogenesis. While all females examined had asynchronous oocyte development, there were remarkable morphological, histochemical, and morphometric differences in the ovarian follicles and enveloping layers. Hoplias malabaricus and H. torrenticola, which exhibit parental care behaviour, had a significantly larger diameter of vitellogenic oocytes and larger spermatozoa nuclei. Apareiodon ibitiensis, H. torrenticola, and A. scabripinnis, species that have rheophilic preferences, exhibited a thicker zona radiata than the other species examined. The follicular cells of R. quelen and H. torrenticola were columnar and produced a jelly coat and mucosubstances, respectively. The females of the seven fish species studied show a correlation of the reproductive strategies with the reproductive system morphology, while males retained more similar morphological characteristics between species. J. Morphol. 278:170-181, 2017. © 2016 Wiley Periodicals,Inc.
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Rafael Magno Costa
authors.initials: RM
authors.lastname: Melo
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Débora Diniz
authors.initials: DD
authors.lastname: Gomes
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Davidson Peruci
authors.initials: DP
authors.lastname: Moreira
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Maysa Regina
authors.initials: MR
authors.lastname: Gomes
authors.affiliation: Programa de Pós-graduação em Zoologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Nilo
authors.initials: N
authors.lastname: Bazzoli
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Elizete
authors.initials: E
authors.lastname: Rizzo
mesh_terms: D000818:Animals; D001938:Brazil; D005260:Female; D005399:Fishes / Q000033:anatomy & histology*; D008297:Male; D045483:Rivers; D014566:Urogenital System / Q000033:anatomy & histology*
keywords: follicle; ovary; spermatozoa; teleosts; testis