INVESTIGADORES
SOMOZA Gustavo Manuel
artículos
Título:
Spawning induction of pejerrey Odontesthes bonariensis in captivity by the use of sustained-release GnRHa implants.
Autor/es:
LEANDRO ANDRÉS MIRANDA; GUSTAVO M. SOMOZA
Revista:
AQUACULTURE RESEARCH
Editorial:
Blackwell
Referencias:
Año: 2009 vol. 41 p. 129 - 134
ISSN:
1355-557X
Resumen:
The aim of this study was to induce and synchronize spawning of pejerrey Odontesthes bonariensis (Valenciennes, 1835), using Gonadotropin Releasing Hormone agonist (GnRHa) implants. In the first experiment, the ovarian condition was assessed by ovarian biopsies and the measurement of the genital pore width (GPW). Females having the leading clutch of oocytes with a diameter around 800-900 ìm and a GPW between 4.5 and 5.5 mm were treated with GnRHa implants. Eighty percent of females spawned between 2 and 9 days after treatment, 12 days earlier than the 20% of fish in the control group that presented signs of spawning activity. In order to avoid any possible ovarian injury and/or stress by the catheterization procedure, in a second experiment, females were selected only by visual inspection of the abdomen and GPW measurement. As in experiment 1, 80% percent of females spawned between 2 and 8, 12  days after treatment, 8 days earlier than the 30% of fish that spawned in the control group. In both experiments, fertilization and hatching success were similar between control and GnRHa-treated groups. These results clearly demonstrated that GnRHa implantation can advance and synchronize ovulation and spawning in pejerrey without affecting egg quality. Odontesthes bonariensis (Valenciennes, 1835), using Gonadotropin Releasing Hormone agonist (GnRHa) implants. In the first experiment, the ovarian condition was assessed by ovarian biopsies and the measurement of the genital pore width (GPW). Females having the leading clutch of oocytes with a diameter around 800-900 ìm and a GPW between 4.5 and 5.5 mm were treated with GnRHa implants. Eighty percent of females spawned between 2 and 9 days after treatment, 12 days earlier than the 20% of fish in the control group that presented signs of spawning activity. In order to avoid any possible ovarian injury and/or stress by the catheterization procedure, in a second experiment, females were selected only by visual inspection of the abdomen and GPW measurement. As in experiment 1, 80% percent of females spawned between 2 and 8, 12  days after treatment, 8 days earlier than the 30% of fish that spawned in the control group. In both experiments, fertilization and hatching success were similar between control and GnRHa-treated groups. These results clearly demonstrated that GnRHa implantation can advance and synchronize ovulation and spawning in pejerrey without affecting egg quality.