Structure of the testis and spermatogenesis of the viviparous teleost Poecilia mexicana (Poeciliidae) from an active sulfur spring cave in Southern Mexico.
J Morphol
; 280(10): 1537-1547, 2019 10.
Article
em En
| MEDLINE
| ID: mdl-31343766
We describe the histological characteristics of the testis and spermatogenesis of the cave molly Poecilia mexicana, a viviparous teleost inhabiting a sulfur spring cave, Cueva del Azufre, in Tabasco, Southern Mexico. P. mexicana has elongate spermatogonial restricted testes with spermatogonia arranged in the testicular periphery. Germ cell development occurs within spermatocysts. As spermatogenesis proceeds, the spermatocysts move longitudinally from the periphery of the testis to the efferent duct system, where mature spermatozoa are released. The efferent duct system consists of short efferent duct branches connected to a main efferent duct, opened into the genital pore. Spermatogenesis consisted of the following stages: spermatogonia (A and B), spermatocytes (primary and secondary), spermatids, and spermatozoa. The spermatozoa are situated within spermatocysts, with their heads oriented toward the periphery and flagella toward the center. Once in the efferent duct system, mature spermatozoa are packaged as unencapsulated sperm bundles, that is, spermatozeugmata. We suggest that the histological characteristics of the testis and spermatogenesis of P. mexicana from the Cueva del Azufre, and the viviparous condition where the spermatozoa enter in the female without been in the water, have allowed them to invade sulfurous and/or subterranean environments in Southern Mexico, without requiring complex morphofunctional changes in the testis or the spermatogenetic process.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espermatogênese
/
Testículo
/
Poecilia
Limite:
Animals
País/Região como assunto:
Mexico
Idioma:
En
Revista:
J Morphol
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Estados Unidos