Seasonal reproduction of male Gambusia holbrooki (eastern mosquitofish) from two Florida lakes.
Fish Physiol Biochem
; 39(5): 1165-80, 2013 Oct.
Article
em En
| MEDLINE
| ID: mdl-23404634
ABSTRACT
Sixteen monthly collections of adult male Gambusia holbrooki (eastern mosquitofish) were obtained from two lakes in central Florida, USA. Lake Woodruff and Lake Apopka are 36 miles apart, but differ in several environmental parameters. Compared with Lake Woodruff, Lake Apopka is warmer, more shallow in sampling areas (particularly during drought conditions; approximately 15-90 cm in Lake Apopka versus 60-120 cm in Lake Woodruff), more turbid, and more heavily contaminated with nutrients and industrial and agricultural chemicals. Here, we present detailed information on seasonal reproduction patterns in mosquitofish in their native range and compare patterns between fish from the two lakes. Male mosquitofish were reproductively active from spring through fall. Spermatogenesis, which is regulated in part by 11-ketotestosterone, ceased in October, and fish stored spermatozoa through the winter for immediate fertilization of offspring in the spring. Compared with Lake Woodruff, fish from Lake Apopka tended to be larger and have longer gonopodia and greater gonado- and hepato-somatic indices (GSI and HSI). High GSI in Apopka fish correlated with greater spermatid production, but fewer mature spermatozoa and either the same or lower sperm counts and sperm viability. Taken together, these observations suggest that differentiation of spermatids to spermatozoa is disrupted in Apopka fish, leading to reductions in fertility in some months. Delivery of sperm to females could also be affected in Apopka fish, which exhibit lower prevalence of efferent duct tissue in the testes during the summer.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Reprodução
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Estações do Ano
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Espermatogênese
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Espermatozoides
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Ciprinodontiformes
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Lagos
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Fish Physiol Biochem
Ano de publicação:
2013
Tipo de documento:
Article