Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-02T22:21:14.091Z Has data issue: false hasContentIssue false

Larval rearing of an Asian catfish Pangasius hypophthalmus (Siluroidei, Pangasiidae): Analysis of precocious mortality and proposition of appropriate treatments

Published online by Cambridge University Press:  15 January 1999

Jojo Subagja
Affiliation:
RIFF (Research Institute for Freshwater Fisheries, Indonesia), Jl Raya II, Sukamandi 41256 Subang, Indonesia
Jacques Slembrouck
Affiliation:
Orstom (Institut français de recherches scientifiques pour le développement en coopération), Instalasi Penelitian Perikanan Air Tawar, Jl. Ragunan - Pasar Minggu, P.O. Box 7220/jkspm, 12540 Jakarta, Indonesia
Le Thanh Hung
Affiliation:
CIRAD-EMVT (Centre international de recherches agronomiques pour le développement), Gamet, BP 3045 34033 Montpellier, France National University of Ho Chi Minh City, Faculty of Fisheries, Thu Duc, Ho Chi Minh City, Vietnam
Marc Legendre
Affiliation:
Orstom (Institut français de recherches scientifiques pour le développement en coopération), Instalasi Penelitian Perikanan Air Tawar, Jl. Ragunan - Pasar Minggu, P.O. Box 7220/jkspm, 12540 Jakarta, Indonesia
Get access

Abstract

Both in Indonesia and Vietnam, larval rearing of Pangasius hypophthalmus remains problematic due to the variable and generally low survival rates obtained. The first week represents the most critical period for these larvae and up to now, cannibalistic behaviour was considered as the main cause of mortality. In the present study, two experiments were carried out in order to better understand the evolution and causes of mortality of P. hypophthalmus larvae from hatching up to 8 d of age and to find measures to improve survival rates. The first experiment was designed to evaluate the importance of cannibalism and differences in mortality when larvae from two different females were reared either in groups of 30 individuals or in isolated condition (30 larvae reared separately). In both cases, the culture was carried out either with or without antibiotic. The aim of the second experiment was to test oxytetracycline and different disinfectants (chloramine-T, formalin and ‘formalin + malachite green oxalate’) at different dosages in order to prevent bacterial outbreaks in the culture. The results indicated that the survival rates of P. hypophthalmus larvae was dependent on the initial quality of larvae or eggs and that larval mortality was more a consequence of pathogenic infection than a direct effect of cannibalism. The present study demonstrated that the survival rates of larvae were systematically improved when rearing was carried out in water containing antibiotic (oxytetracycline at a dose of 5 to 20 mg·L−1). Survival rate and final mean body weight of larvae as high as those obtained using antibiotic were also reached with applications of disinfectants such as chloramine-T and formalin. The use of these disinfectants is recommended for commercial P. hypophthalmus hatcheries.

Type
Research Article
Copyright
© Elsevier, Inra, Ifremer, Cemagref, Ird, Cnrs, 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)