Resumen

NAVARRO, Rodrigo Diana et al. Induced spawning of curimbatá (Prochilodus affinis) with use of hypophyseal raw extract of bull frog (Rana catesbeiana). Zootecnia Trop. [online]. 2007, vol.25, n.2, pp.143-147. ISSN 0798-7269.

The main objective of this work was to determine the effect of the use of hypophyseal raw extract to induce fish spawning in curimbatá specie. An election of females of frog bull (Rana castesbeiana) was carried through for extraction of hyphophysys, where the female donors had been those that presented an increment of their visceral socket, which was provoked by ovaries in mature phase or advanced maturation. Twenty curimbatá breeders (Prochilodus affinis) had been used for spawning. The males had an initial average weight of 170.0 g and an average length of 21.72 cm and the females with an initial weight average of 181.0 g and an average length of 6.28 cm. The experiment was carried through with 2 treatments: Treatment 1: 0.5 mg/kg and Treatment 2: 0.7mg/kg. The animals were stocked in aquarium with 1000 L capacity with constant aeration. The females received two intramuscular injections of frog bull raw extract, being the first dose of 0.5 mg/kg and the second 0.7 dose of mg/kg, with interval of 12 hours. The females with dosages of 0.5 mg/kg had obtained a superior number of larvae than those  with 0,7 mg/kg. The difference was statistical significant (P>0,06). This result was probably due to different stadiums of gonadal maturation. Both dosages (0.5 and 0.7 mg/kg) of frog bull hypophyseal raw extract had allowed to induce reproduction of curimbatá females, showing an alternative in the reproductive handling.

Palabras clave : raw hypophyseal extract; induced spawning; reproduction; Prochilodus affinis.