Reproductive response of Gymnotus sp. to induction with carp pituitary extract

LÓPEZ, P.A.; RODRIGUES-FERREIRA, M.; VIGLIANO, F.A.; SOLIS-MURGAS, L.D.

Villavicencio

Congreso; IV Conferencia Latinoamericana sobre Cultivo de Peces Nativos; 2013

Universidad de Los Llanos

In this study, the reproductive response of Gymnotus sp. to induction with carp pituitary extract (CPE) was assessed. Adult fish [10 females (F), 18 males (M)] were injected intramuscularly with a priming dose of 0.5 and a final dose of 5.0 mg kg-1of CPE. Two groups, named A (n=6F/9M) and B (n=4F/9M) were stripped after 20 and 32 hours after the final dose, respectively. A control group (C) (n=5F/5M) was injected with saline solution. Spawning were only obtained in A in one third of females. There were significant differences for ratio of peripheral germinal vesicle between B and C with a higher value in B (p less than 0.01), and oocyte diameter between C and both treatments with a higher value in C (p less than 0.0001). Only induced males were successfully stripped. No significant differences for milt volume or sperm concentration were found between A and B. Mean values for motility were over 90% in both groups. Serum levels of LH did not present significant differences in females, although values on males in B were higher (p less than 0.05) than in C. Although this preliminary results are promising, further studies with different hormones and protocols must be conducted in order to achieve reproduction successfully.