REDUCING ARTEMIA USE IN LARVAL MARINE FISH CULTURE :
AN EXPERIMENT USING ATLANTIC COD (GADUS MORHUA)
A.
Jordaan, C. Callan, L.J. Kling
Abstract:
The use of Artemia for the feeding of larval marine
fish constitutes a significant portion of total culturing costs. Two
experiments were conducted to determine whether early weaning of cod (Gadus
morhua) larvae in conjunction with co-feeding of microparticulate diet (MPD)
could reduce Artemia use. Experiment 1 started weaning at 22 days post-hatch
(dph) and experiment 2 at 8 dph. Both experiments were divided into a
control group (100% Ar), which was fed only live food, and three
experimental treatments (n=3 for all). The experimental treatments were as
follows: MPD and 50% the amount of Artemia as the 100%Ar treatment (50%Ar),
MPD and 25% of the amount Artemia (25%Ar), and MPD only (MPD). Standard
lengths and dry weights were collected throughout the experiments. Survival
was calculated by counting all remaining fish at the conclusion of the
experiments. In both experiments the results indicated that the 100%Ar,
50%Ar and 25%Ar groups did not differ significantly in growth or survival.
However, the MPD treatment had significantly lower growth and survival than
the 100%Ar and 50%Ar treatments. The total feed costs were $0.03, $0.016,
$0.01 and $0.019 per remaining fish for the 100%Ar, 50%Ar, 25%Ar and MPD
treatments respectively. We believe that significant savings are possible
for marine larval fish culture by using feeding strategies similar to those
presented here.
(School of Marine Sciences, 214 Libby Hall,
University of Maine, Orono, ME 04469, USA)