Baras Etienne, Hafsaridewi R., Slembrouck Jacques, Priyadi A., Moreau Yann, Pouyaud Laurent. (2013). Do cannibalistic fish possess an intrinsic higher growth capacity than others ? A case study in the Asian redtail catfish Hemibagrus nemurus (Valenciennes, 1840). Aquaculture Research, 45 (1), p. 68-79. ISSN 1355-557X.
Titre du document
Do cannibalistic fish possess an intrinsic higher growth capacity than others ? A case study in the Asian redtail catfish Hemibagrus nemurus (Valenciennes, 1840)
Baras Etienne, Hafsaridewi R., Slembrouck Jacques, Priyadi A., Moreau Yann, Pouyaud Laurent
Source
Aquaculture Research, 2013,
45 (1), p. 68-79 ISSN 1355-557X
This study relied on the day-by-day analysis of bioenergetics and prey size preference in larvae and juveniles of Hemibagrus nemurus selected at random, held in isolation (28.5 degrees C, 12L:12D) and feeding ad libitum on conspecifics [21 fish, 12-46mm total length (TL), dry mass (DM) of 1-145mg]. Several traits concur to make young H. nemurus highly cannibalistic: (1) high predation capacities (largest prey=88% and 70% TL in fish of 8 and >40mm TL, respectively), (2) opportunistic feeding behaviours with no marked size preference and (3) an unusual combination of high food intake (>100% DM at 1mg DM) and very high gross conversion efficiency (>0.70). A growth model was constructed from the top performances of fish feeding maximally (16 of 21 fish) and indicated that the risk of cannibalism would be high and permanent except for meal frequencies over five daily meals. Cannibals emerging spontaneously under communal rearing (6 fish L-1, three daily meals) grew more slowly or just at the same rate as predicted by the growth model constructed from siblings selected at random. This indicates that the individuals that become cannibals do not possess higher intrinsic capacities for growth than others.
