Histological changes in the corpuscles of Stannius during the reproductive cycle of males and females of curimbata, Prochilodus scrofa (Steindachner, 1881) (Pisces, Cipriniformes)

Abstract

Corpuscles of Stannius from 80 adult males and 80 adult females of curimbatá (Prochilodus scrofa) were processed for histological analysis. Twenty fishes of each sex were collected during each of the four stages of the reproductive cycle, namely: resting, maturing, ripening and spent. Corpuscles of Stannius were fixed in Bouin fluid, (imbibed) in paraffin and stained by HE and Mallory trichrome methods. The results showed that, during the resting stage, uniformity of nuclear and cellular volumes of the main type of parenchymal cell were observed. In the maturing and ripening stages cellular and nuclear hypertrophy and hyperplasia (mitosis) were detected . On the other hand, the spent stage was characterized by volumetric reduction of the parenchymal cells, which also presented nuclear picnosis, suggesting cellular degeneration. Males seemed to have more conspicuous histological changes than females. Histological data indicated that the highest activity of the corpuscles of Stannius was detected during the maturing and ripening stages of reproductive cycle.