Reproductive biology of Percophis brasiliensis, (Quoy et Gaimard, 1824) in coastal waters off Buenos Aires Province

MILITELLI, M I; MACCHI,

Capital Federal

Taller; Taller de Biología de la reproducción y del desarrollo embrionario, Facultad de Veterinaria, UBA; 2000

The reproductive biology of Percophis brasiliensis sampled during December 1998 in coastal waters off Buenos Aires province (36° - 42° S) , was studied by using macroscopic and microscopic gonad analysis. The size at first maturity of this species showed high significant differences (P< 0.01) between  sexes, being of 28.98 Lt cm for males and 38.34 Lt cm for females. Microscopic analysis of the ovaries showed that this species is a batch spawner. At the beginning of December reproductive activity decreased and a high percentage of atresia was observed. Spawning females (with hydrated oocytes) were concentrated in shallow waters near Claromecó and Necochea (38° 30’- 39º S), in coincidence with a bottom thermal front, between 14 and 16ºC. Spawning frequency determined by using the incidence of females with one-day-old postovulatory follicles was about 6 days. Mean batch fecundity was 188,912 hydrated oocytes for one 56-cm-TL female. This variable was a power function of length and a linear function of ovary-free body weight. Relative fecundity ranged between 155 and 369 hydrated oocytes per female gram (ovary-free).