Reproductive biology of Pseudocorynopoma doriai (Pisces: Characidae) in the High Basin of the Samborombón River, province of Buenos Aires, Argentina.

RICARDO A. FERRIZ; EDUARDO M. FERNÁNDEZ; CRISTINA A. BENTOS; GUILLERMO R. LÓPEZ

JOURNAL OF APPLIED ICHTHYOLOGY-ZEITSCHRIFT FUR ANGEWANDTE ICHTHYOLOGIE

Blackwell Verlag

Lugar: Berlín; Año: 2007 vol. 23 p. 226 - 230

0175-8659

Summary The reproductive period of the Glandulocaudine Pseudocorynopoma doriai was determined by the analysis of 240 females, 90 males and 138 immature individuals collected monthly in the Manantiales and the El Portugue´ s rivers. The reproductive period is seasonal, occurring from  ate winter to mid-summer, with another reproductive peak of smaller magnitude in early autumn. The mean monthly GSI in males has a signi.cant correlation with rainfall. Other analyzed environmental variables, including temperature, photoperiod, pH and conductivity, did not show a correlation with the mean monthly GSI in females and males. First maturity in females was reached within the 42–43 mm standard length class. Like other Glandulocaudines from southern Brazil, males initiate sexual maturation before females, which implies an adaptive advantage in that this would enable females to spawn under optimal environmental conditions. The mean absolute fecundity was 1286.42 oocytes (SD ¼ 496.9083); the mean relative fecundity was 0.5070 (SD ¼ 0.1333) oocytes by milligram body weight.