Growth and Culture of Larval and Juvenile Tautogs in a Closed Recirculating-Seawater System
D.M. Perry, R.Mercaldo-Allen, S. Burgh-2001
North American Journal of Aquaculture, 63(4): 300-305
Abstract:
Field-captured and laboratory-held adult tautogs Tautoga
onitis were allowed to spawn naturally under laboratory conditions.
Embryos were cultured to hatching and raised successfully through the larval
stage to 490-d-old posthatch juveniles. A large (8,500-L), closed,
recirculating-seawater system, designed with a biological filter containing
air diffusers that passed a strong air-water
mixture through a high-surface-area substrate, was used to culture the
larvae and juveniles. The biological filter provided biofiltration,
aeration, degassing, and foam fractionation without disturbing the larvae.
Water quality measures within the system were maintained at acceptable
values. Enrichment of rotifers and brine shrimp Artemia sp. with
algal strains containing highly unsaturated fatty acids, plus wild
zooplankton, provided an adequate diet for larval growth. Also, a commercial
feed was given at 2 weeks and larval tautogs were observed eating it.
Juvenile tautogs were fed enriched adult brine shrimp along with wild
zooplankton and increasingly larger sizes of a commercial feed every 4-7
weeks. At 23 weeks of age, live foods were discontinued and the fish
received only commercial feed for the remainder of the study. These feeds
provided adequate diets for growth through the larval and juvenile stages.
Growth in the length of the juvenile tautogs was linear from 172 to 490 d of
age. The estimated growth rate, based on direct measurements of growth, was
0.29 mm/d, which is similar to the rates reported for other
laboratory-reared juvenile tautogs and for other labrids.
(National Marine Fisheries Service, Northeast
Fisheries Science Center, Milford Laboratory, 212 Rogers Avenue, Milford,
Connecticut 06460, USA)