The effect of
temperature on first feeding, growth, and survival of larval witch flounder
Glyptocephalus cynoglossus
D.A. Bidwell, W.H. Howell-2001
Journal of the World Aquaculture Society, 32(4):
373-384 (from Current Contents)
Abstract :
Witch flounder Glyptocephalus cynoglossus has
recently been identified as a candidate species for aquaculture in the
northeastern United States and the Canadian Atlantic Provinces. This study
investigated the optimal temperatures for witch flounder larval first
feeding and for long term larval culture from hatching through
metamorphosis. Maximum first feeding occurred between 15.0 and 16.2 C.
Larvae did not survive beyond first feeding when reared at mean temperatures
of 5.1, 10.4, or 19.5 C and were unable to initiate feeding at mean rearing
temperatures below 6.0 C. At a rearing temperature of 15.0 C in 16-L tanks,
mean larval survival to 60 days post hatch (dph) seas 14.1 %. Mean overall
length-specific growth rate for larvae reared to 60 dph at 15.0 C was 3.5%/d
and mean absolute growth was 0.62 mm/d. Subsequent larval growth at 15.6 C
began to taper off towards 70 dph at the onset of weaning which overlapped
with larval metamorphosis. Growth plateaued at 85 dph, followed by a rebound
between 90 and 95 dph. Survival was 100% when weaning onto a dry, pelleted
diet was initiated at 70 dph with a 10-d live diet co-feeding period. These
results are favorable and encourage the further pursuit of commercial witch
flounder culture.
(Univ New Hampshire, Dept Zool, Durham, NH 03824,
USA)