Why is cannibalism less frequent when larvae of sutchi catfish Pangasianodon hypophthalmus are reared under dim light?

Mukai, Yukinori and Tan, Nai Han and Lim, Leong Seng (2015) Why is cannibalism less frequent when larvae of sutchi catfish Pangasianodon hypophthalmus are reared under dim light? Aquaculture Research, 46. pp. 1958-1964. ISSN 1365-2109

	PDF - Published Version Restricted to Repository staff only Download (305kB) | Request a copy
	PDF (wos and scopus) - Supplemental Material Restricted to Repository staff only Download (438kB) | Request a copy

Abstract

Survival rates of the larvae of sutchi catfish Pangasianodon hypophthalmus are reported to be three times higher under dim conditions (0.1 lx) than those under 100 lx. In this study, larval behaviour of sutchi catfish was examined under various light intensities (<0.01, 0.1, 1, 10 and 100 lx) using a CCD camera to understand why survival rates vary under different light intensities. Five-day-old larvae showed significantly higher swimming activity under <0.01, 0.1 and 1 lx than those under 10 and 100 lx. On the other hand, the larvae showed significantly higher aggressive behaviour under 10 and 100 lx; swimming larvae attacked resting individuals more frequently under 10 and 100 lx than those under 0 and 0.1 lx. Aggressive behaviour was considered to induce lesions, inflicted by the sharp teeth of attacking larvae, on larval skin surfaces. It is considered that the chemical substances would generate from injured skin surfaces then acted as stimuli, causing the cannibalistic behaviour in other fish around the injured fish. This study provided evidence that the observed higher survival rates depended on lower frequency of aggressive behaviour under dark or dim conditions. It is therefore recommended that larval rearing of sutchi catfish be conducted under dim (less than 1 lx) conditions.

Item Type:	Article (Journal)
Additional Information:	6616/45466
Uncontrolled Keywords:	sutchi catfish, Pangasianodon hypophthalmus, cannibalistic behaviour, dim conditions, larval behaviour
Subjects:	S Agriculture > SH Aquaculture. Fisheries. Angling
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Science > Department of Marine Science
Depositing User:	Dr. Yukinori Mukai
Date Deposited:	30 Oct 2015 16:00
Last Modified:	25 Sep 2017 15:34
URI:	http://irep.iium.edu.my/id/eprint/45466

Actions (login required)

View Item