Reproductive response of Gymnotus sp. (Teleostei: Gymnotiformes) to hormonal induction Respuesta reproductiva a la inducción hormonal en Gymnotus sp. (Teleostei, Gymnotiformes)

LÓPEZ, P.A.; MACHADO, RODRIGUES FERREIRA M.; DE OLIVEIRA FELIZARDO, V.; MURGAS, L.D.S.; VIGLIANO, F.A.

Revista Veterinaria

Universidad Nacional de Nordeste (UNNE)

Lugar: Corrientes; Año: 2023 vol. 34 p. 61 - 68

1668-4834

Technological development for Gymnotus sp. farming is relevant because this species has a socioeconomic impact in South American regions where sport fishing is an important activity. Although Gymnotus sp. breeds in captivity, fry survival in ponds can be unacceptable for culture systems. The objective of this work was to test the response to hormonal induction of Gymnotus sp. with carp pituitary extract (CPE) and gonadotrophin-releasing hormone (GnRH) in relation to different male and female reproductive parameters. CPE treatment specimens were stripped 12 and 20 hours after the triggering dosage, and GnRH treatment specimens were stripped 10 and 12 hours after hormonal application. We could obtain positive results using CPE with a short capture-induction interval (C-II) with broodstock in mature stages of gonadal development. Percentage of oocytes with peripheral germinal vesicle (%OPGV) and oocyte diameter showed significant differences between groups treated with CPE. Oocytes could be successfully extracted from two females treated with CPE and stripped 12 hours after the last dosage. Semen was only extracted from males treated with CPE. GnRH stimulation did not give positive results because gametes could not be extracted with different doses and C-II used. This work is the first description of semen quality parameters in Gymnotus sp. Future works should focus on combining hormonal induction strategies with CPE and the management of environmental variables.