The effect of diet type and
quantity on the development of common sea urchin larvae Echinus
esculentus
R.A. Jimmy, M.S. Kelly, A.R. Beaumont-2003
Aquaculture, 220(1-4): 261-275
Abstract:
Several species of sea urchins are now being
cultivated for commercial purposes and with the continued increased demand
for sea urchin gonads as a food product, new species are being assessed for
their aquaculture and market potential. This study focussed on establishing
protocols for the production of common sea urchin Echinus esculentus
larvae and juveniles to assess its potential as an echinoculture species.
Two trials were carried out, the first trial evaluated the influence of
three microalgal diets (D=Dunaliella tertiolecta only, mixed D/P=D.
tertiolecta plus Phaeodactylum tricornutum and P=P.
tricornutum only) on larval morphology. Larval length, width, post-oral
arm length and rudiment length were significantly effected by diet. Diets D
and D/P prompted more rapid metamorphosis. In the second trial, the effects
of different rations of D. tertiolecta were tested. The food ration,
standard ration (SR; 1000, 3000, and 5000 cells ml-1) and high
ration (HR; 3000, 9000, and 15,000 cells ml-1) were increased as
the larvae acquired the 3rd and 4th pair of larval arms. Larvae fed the SR
were significantly larger (longer and wider) and had significantly longer
rudiments than those in the HR treatment. The number of larvae
metamorphosing and settling onto substrates was significantly higher in
treatment SR compared to HR. Optimising the larval diet shortened the larval
stage from 21–23 days in the first trial to 16 days in the second trial.
The maximum percentage of metamorphosing individuals which survived to
post-larvae or juveniles (10 days after they were first judged competent to
settle) was 46.6%, suggesting E. esculentus is a viable aquaculture
candidate.