The effects of density on
the growth and survival of different families of juvenile Penaeus
japonicus Bate
G.J. Coman, P.J. Crocos, N.P. Preston, D.
Fielder-2004
Aquaculture, 229(1-4): 215-223
Abstract:
Variations in the growth and survival of six families
of juvenile (initial mean WEIGHT=4.16 g) Penaeus japonicus were
examined at two densities (48 and 144 individuals m-2) in a
controlled laboratory experiment. Survival was very high throughout the
experiment (95.4%), but differed significantly between densities and rearing
tanks. Family, sex and family×density interaction did not significantly
affect survival. Mean specific growth rate (SGR) of the shrimp was 18%
faster at the low density (1.93±0.05% day-1) than at high
density (1.64±0.03% day-1). However, there was a small but
significant interaction between family and density indicating that growth of
the families was not consistent at both densities. The inconsistent growth
of the families across the two densities resulted in a change in the
relative performance (ranking) of families at each density. Sex, rearing
tank and rearing cage also affected growth of the shrimp. Mean SGR of the
females (1.79±0.03% day-1) was 5% faster than males (1.70±0.03%
day-1) when averaged across both densities. Shrimp grew
significantly faster in rearing tank 3 than rearing tank 1 or 2 at both
densities. Results of the present study suggest that family×density
interaction could affect the efficiency of selection for growth if shrimp
stocks produced from shrimp breeding programs are to be grown across a wide
range of densities.
(CSIRO Marine Research, P.O. Box 120, Queensland
4163, Australia, e-mail: Greg.Coman@csiro.au)