Effects of varying latency period on the in vivo survival of ova after Ovaprim- and hCG-induced ovulationin the Asian catfish Pangasius hypophthalmus (Siluriformes, Pangasiidae)

1998

Colloque

Legendre Marc, Slembrouck Jacques, Subagja J., Kristanto A.H.

Legendre Marc (ed.), Pariselle Antoine (ed.), The biological diversity and aquaculture of clariid and pangasiid catfishes in South-East Asia : proceedings of the mid-term workshop of the "Catfish Asia project"

Jakarta (IDN) ; Can Tho : IRD ; Can Tho University, 1998, p. 119-125

Characterisation, Utilisation and Maintenance of Biological Diversity for the Diversification and Sustainability of Catfish Culture in South East Asia, Can Tho (VNM), 1998/05/11-15

Over a 2-year period at the Sukamandi station (West Java, Indonesia), 87 P. hypophthalmus females selected on the basis of a modal oocyte diameter greater than 1.0 mm were treated with Ovaprim (n=77) or hCG (n=10) to induce oocyte maturation and ovulation. The two hormonal treatment led to similar results in terms of ovulation percentage (86 and 90%), hatching rates (69 plus or minus 28 and 82 plus or minus 11%) and relative fecundity (167,000 plus or minus 18,000 and 128,000 plus or minus 60,000 eggs/kg, with Ovaprim and hCG respectively. The latency period between the last hormone injection and ovulation was negatively correlated to water temperature but showed important variations at a same temperature depending on individual females (e.g. between 5-11 h at 28-29°C). The ovulation time was therefore difficult to predict accurately in this species. The assessment of survival time of ova maintained in ovario after ovulation showed that the process of ageing (overripening of ova) occurs rapidly in P. hypophthalmus. The overall quality of ova begun to decrease as early as 2 hours after ovulation and, after 3 hours, hatching rate dropped down and fraction of deformed larvae increased significantly in comparison to those observed at the moment of ovulation. In some individual females this evolution was even more rapid, with a sharp decrease in hatching rates between 1 and 2 hours post-ovulation. The duration of ova survival did not appear to depend on the type of hormonal treatment used (Ovaprim or hCG). For optimised gamete management in hatcheries, it is therefore recommended to check carefully the females for the occurrence of ovulation (between 3 to 11 h after the last hormone injection, depending on water temperature) and to collect and fertilise the eggs within less than two hours after this moment. (Résumé d'auteur)

Aquaculture [040AQUAC]

POISSON D'EAU DOUCE ; PISCICULTURE ; METHODE D'ELEVAGE ; REPRODUCTION ; INDUCTION ; HORMONE ; OVOCYTE ; OEUF ; LARVE ; TAUX DE SURVIE ; ECLOSION ; FECONDATION ; ETUDE EXPERIMENTALE ; REPRODUCTION ARTIFICIELLE ; TRAITEMENT HORMONAL ; GNRH ; DOMPERIDONE ; OVAPRIM ; HCG.HUMAN CHRONIC GONADOTROPINE

INDONESIE ; JAWA

Fonds IRD [F A010020339] ; Montpellier (Centre IRD)

fdi:010020351