Effects of feeding live or
frozen prey on growth, survival and the life cycle of the cuttlefish, Sepia
officinalis (Linnaeus, 1758)
P. Domingues, A. Sykes, A.
Sommerfield, J.P. Andrade-2003
Aquaculture International, 11(5):
397-410
Abstract:
The effects of feeding live or frozen grass shrimp (Palaemonetes
varians) to the cuttlefish, Sepia officinalis, were determined
in two experiments. During Experiment I, two populations of 30 cuttlefish
(aged 90 days old) were fed either live or frozen grass shrimp. Cuttlefish
fed live shrimp grew larger, matured earlier, had a shorter life cycle (255
days) than the ones fed frozen shrimp (282 days), and had lower mortality.
Females from the group fed frozen shrimp matured a month later but were
significantly larger, 130.9 ± 38.5
g, compared to 74.2 ± 16.0
g, laid larger eggs, 0.47 ± 0.11
g, compared to 0.28 ± 0.10
g, and had higher individual fecundity (411 eggs
female-1, compared to 150 eggs
female-1). Newly born hatchlings from both groups had
similar weights. During Experiment II, six replicates of 15 cuttlefish (50
days old) were used, three for each of the two diets tested. The exact same
amount of live or frozen shrimp was provided to both populations twice a
day. No differences in growth and feeding rates or food conversions were
found at the end of the experiment. During the first week, cuttlefish fed
frozen shrimp grew larger, and had higher conversion rates, compared to the
ones fed live shrimp. Mortality was higher for the group fed live shrimp
(36.6%) in Experiment II, mainly occurring during the last week. Mortality
for cuttlefish fed frozen shrimp in Experiment II was 2.2%. Results obtained
here indicate that freezing the grass shrimp only had a negative effect on
the survival of S. officinalis in Experiment I.
(Faculdade de Ciências
do Mar e do Ambiente, CCMar –
Universidade do Algarve, Campus de Gambelas –
8000-810 Faro, Portugal, e-mail: pdoming@ualg.pt)