Description of the ovarian follicle growth of the neotropical cichlids Petenia splendida and Parachromis managuensis (Perciformes : Cichlidae)

Abstract

The ovarian follicle growth in Petenia splendida and Parachromis managuensis was analyzed. Both species presented analogous follicular growth, reaching similar values within the gonadosomatic and somatic indices (I-G) to those reported in other cichlids

however, with regard to maturity, these indices were significantly greater in Pe. splendida than in Pa. managuensis. The histology of oogenesis coincided with that known from most teleosts, except for one difference: the granulosa layer of Pa. managuensis was composed of pseudo-stratified columnar cells, whereas other species presented columnar cells. Another conspicuous difference was registered in the first stage of oocyte maturation: Pa. managuensis exhibited the entire spectrum from primary to vitellogenic follicles, whereas in Pe. splendida only primary follicles occurred at that stage. It is concluded that Pa. managuensis shows a reproductive strategy with very short spawning periods, influencing the colonization capacity in the Grijalva-Usumacinta River system. Both species, however, may still be considered as synchronic breeders, based on the characteristics of the maturation process of their oocytes despite their slightly different mode.