Biologia reprodutiva e desova induzida de duas espécies de bagres (Osteichthyes: Siluriformes) da bacia do rio São Francisco

Abstract

Rhamdia quelen and Pseudopimelodus charus are two catfish species that can reach more than 2 kg. The specimens received one dose of crude carp pituitary extract (CCPE) (2.5 mg kg-1 for males and 6 mg kg-1 for females). Oocyte extrusion was done after 12.2 and 12.3 hours after the CCPE injection in R. quelen and P. charus respectively, at water temperature of 26°C. More than 75% of the females of both species presented a positive response to the treatment, with mean rates of oocytes fertilization above 75%. The oocytes of P. charus and R. quelen are spherical, opaque, demersal, non adherent and covered by a jelly coat. There were found a mean number of 1073 and 1128 oocytes per gram respectively and the larvae of the two species ecloded around 21h after oocyte fertilization at 24°C.