Timing and
factors affecting cannibalism in red drum, Sciaenops ocellatus, larvae in
captivity
I.C.
Liao, E.Y. Chang-2002
Environmental Biology of Fishes, 63(2): 229-233
(from Current Contents)
Abstract :
Since 1987, when the red drum, Sciaenops ocellatus,
was introduced into Taiwan, research has been concentrated on its
feasibility and biological studies applied to aquaculture. As a part of
these biological studies, an experiment was conducted to investigate the
timing and factors affecting cannibalism in red drum larvae in captivity.
Experimental larvae were graded into small and large sizes. Four treatments
were then applied: (1) the control group, (2) water turbidity increased by
adding green algae, (3) density of larvae increased twofold, and (4)
satiation feeding with Artemia nauplii. Each treatment was triplicated, each
in a 12 l test tank stocked with 20 large and 20 small test larvae except
those with doubled density of larvae. In a period of three days, the size
difference in test larvae was found to be the most important factor
affecting cannibalism, whereas water turbidity and density of larvae showed
no apparent effect. Satiation feeding significantly decreased but did not
stop cannibalism. The peak stage of cannibalism for red drum larvae was
likely to occur at a total body length of 1.8-1.9 cm, when the ratio of
lower jaw length to total body length was at its maximum.
(Taiwan Fisheries Res Inst, 199 Hou Ih Rd, Chilung
202, Taiwan, e-mail: icliao@mail.tfrin.gov.tw)