(The size composition of the oocytes and fecundity of the Brasilian catfish, Rhandia hilarii (Valenciennes, 1840) (Siluriformes, Pimelodidae).

Abstract

A total of 213 females of the Brazilian catfish, Rhamdia hilarii, was collected during two years (1973/1975) from the Jaguari River (Jaguariúna, SP) in order to know the fecundity and the spawning frequency. Through analysis of the percent frequency distribution of the egg diameter of females in different stages of gonad development, it was concluded that the species presents asynchronous development of eggs and partial spawning. The absolute fecundity varied from 5,500 through 52,875 eggs (1973/1974) and from 6,250 through 46,250 (1974/1975). The relationships between fecundity and total length, total weight and ovary weight were analyzed. The fecundity was found to be closer related to ovary weight.