Frozen mysids as an alternative to live Artemia in culturing
seahorses Hippocampus abdominalis
Ch.M.C.
Woods, F. Valentino-2003
Aquaculture
Research, 34(9):
757
Abstract:
This
investigation examined the effects on growth and survival of seahorses Hippocampus
abdominalis Leeson 1827 fed a 25% body weight (wet weight) daily ration
of live Artemia sp. enriched with Algamac-3050, frozen mysids Amblyops
kempi or a combination of live enriched Artemia and frozen
mysids. After 3 months there was no difference in seahorse length, wet
weight, condition factor (CF), or food conversion ratios (FCR) between the
treatments. Mean daily specific growth rate (SGR) was higher for the Artemia-only
treatment than for the mysid-only treatment (P<0.05). FCRs ranged
from 6.14 g to 8.72 g dry weight of food required to give a 1-g dry weight
increase in seahorses. There was no difference in survival between
treatments. Fatty acid analysis revealed that mysids had a higher percentage
composition of EPA, 20 : 5n-3, and DHA, 22 : 6n-3, but a
lower composition of AA, 20 : 4n-6, than enriched Artemia.
Percentage n-3 highly unsaturated fatty acids (HUFAs) in mysid levels were
approximately twice that of Artemia. Proximate analysis revealed
mysids to be higher than the enriched Artemia in protein and fats,
and lower in water content. This experiment demonstrates that, although no
growth advantage was derived from the use of frozen mysids, they can be used
successfully as an alternative food to live enriched Artemia for H.
abdominalis. The use of frozen mysids is highly recommended in
commercial seahorse culture if the seahorses are to be sold into the live
aquarium trade, as this may increase their chances of survival after sale.
(National Institute of Water and
Atmospheric Research, PO Box 14-901, Wellington, New Zealand. E-mail: c.woods@niwa.cri.nz)