* Genovese: autor correspondiente. Dynamics of ovarian maturation throughout the reproductive cycle of the Neotropical cichlid fish Cichlasoma dimerus (Teleostei, Perciformes). *Genovese & Meijide corresponding author

VARELA, M.L.; FERREIRA, M.F.; DA CUÑA, R.; LO NOSTRO, F. L.; GENOVESE, G.; MEIJIDE, F

CANADIAN JOURNAL OF ZOOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2017 vol. 95 p. 485 - 498

0008-4301

In this study, we analyzed gene expression profiles, plasma steroids concentrations, and gonadal morphologythroughout the reproductive cycle of female Cichlasoma dimerus (Heckel, 1840), a monogamous cichlid fish exhibiting socialhierarchies. Fish were analyzed at six phases encompassing their annual cycle, namely resting (during the nonreproductiveperiod), prespawning, 30 h post spawning, 4 days post spawning, 10 days post spawning, and subordinate (during the reproductiveperiod). The histological and histomorphometric analysis showed that C. dimerus exhibits asynchronous ovarian development.Similar to resting females, subordinate females showed low gonadosomatic index, reduced expression levels ofvitellogenin (vtgAb), zona pellucida (zpB), gonadal aromatase (cyp19a1A), and low concentrations of plasma sex steroids, thusindicating that social intimidation by dominant conspecifics elicited reproductive arrest. In reproductively active females, adirect positive correlation between plasma estradiol, vtgAb expression, percentage of late vitellogenic oocytes, and gonadosomaticindex was observed. These parameters were maximal at the prespawning phase, decreased at 30 h post spawning and4 days post spawning, and then reached a peak at 10 days post spawning. Our results indicate that female C. dimerus becomespawning capable after 10 days post spawning, coincidently with the shortest time interval between successive spawns recordedin captivity.