Food for seahorse food
Many commercial culturists still rely to various
degrees on culturing live prey, such as brine
shrimp and copepods, to feed their seahorses. What
the brine shrimp and copepods are themselves fed
on critically influences their nutritional value,
and therefore affects seahorse growth, survival,
coloration, and health. Numerous commercial feed
and enrichment products are available for growing
these live prey, costing from as little as $4/kg
to over $200/kg. The obvious question for most
culturists is, “Which is the most cost effective
for culturing seahorses?” We recently tested
a range of |
 |
|
enrichment products
for their effects on brine shrimp nutritional
value, and on seahorse growth and survival when
fed on these variously enriched brine shrimp.
Food for seahorses
Weaning seahorses off live foods on to artificial
foods is highly desirable to reduce culture costs
and guarantee feed quality and supply. To date,
this has proved difficult in large-scale
commercial culture, although we have had some
success experimentally at NIWA’s Mahanga Bay
research facility (with our results soon to be
published in Aquaculture). More readily
achievable is the weaning of seahorses off live
food on to frozen natural products, such as mysid
shrimp and copepods. Home aquarists often have
reasonable success doing just this. The ability to
wean seahorses on to frozen food is critically
important to culturists targeting the aquarium
market because many aquarium wholesalers,
retailers, and customers use frozen foods, and the
seahorses need to be adapted to frozen food if
they are not to be poorly fed or stressed between
initial sale and final purchase. Non-weaned
seahorses, and in particular wild-captured
seahorses, have a lower survival rate during
trading. We tested the ability of Hippocampus
abdominalis to be weaned on to frozen mysids,
and compared the growth and survival of seahorses
fed on frozen mysids with seahorses fed enriched
live brine shrimp.
Food for thought
Some of the results of our enrichment product
testing were surprising, and have potential
cost-saving implications for commercial seahorse
culture. For example, an $11/kg rice bran and
Spirulina product gave better growth than a
commonly used $270/kg fish oil enrichment.
In our weaning
test, growth and survival were the same for
seahorses fed on frozen mysids and on live brine
shrimp, but, more importantly, the weaning of
H. abdominalis proved very easy. This bodes
well for improving the economic efficiency of
commercial culture of this species, because it
reduces the need to culture larger live prey for
the seahorses as they grow bigger.
Chris Woods
c.woods@niwa.co.nz
|
