Aggressive behavior and reproductive physiology in females of the social cichlid fish Cichlasoma dimerus

The South American cichlid fish Cichlasoma dimerus is a freshwater species that presents social hierarchies, a highly organized breeding activity, biparental care and a high frequency of spawning. Spawning is followed by a period of parental care (about 20 days in aquaria conditions) during which th...

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Detalles Bibliográficos
Autores: Tubert, Cecilia, Lo Nostro, Fabiana Laura, Villafañe, Virginia, Pandolfi, Matias
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/113535
Acceso en línea:http://hdl.handle.net/11336/113535
Access Level:acceso abierto
Palabra clave:agresividad
ciclidos
GnRH
Esteroides sexuales
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:The South American cichlid fish Cichlasoma dimerus is a freshwater species that presents social hierarchies, a highly organized breeding activity, biparental care and a high frequency of spawning. Spawning is followed by a period of parental care (about 20 days in aquaria conditions) during which the cooperative pair takes care of the eggs, both by fanning them and by removing dead ones. The different spawning events in the reproductive period were classified as female reproductive stages which can be subdivided in four phases, according to their offspring degree of development: (1) female with prespawning activity (day 0), (2) female with eggs (day 1 after fertilization), (3) female with hatched larvae (day 3 after fertilization) and (4) female with swimming larvae (FSL, day 8 after fertilization). In Perciform species gonadotropin-releasing hormone type-3 (GnRH3) neurons are associated with the olfactory bulbs acting as a potent neuromodulator of reproductive behaviors in males. The aim of this study is to characterize the GnRH3 neuronal system in females of C. dimerus in relation with aggressive behavior and reproductive physiology during different phases of the reproductive period. Females with prespawning activity were the most aggressive ones showing GnRH-3 neurons with bigger nuclear and somatic area and higher optical density than the others. They also presented the highest levels of plasma androgen and estradiol and maximum gonadosomatic indexes. These results provide information about the regulation and functioning of hypothalamus–pituitary–gonads axis during reproduction in a species with highly organized breeding activity.