EFFECTS OF STOCKING DENSITY ON GROWTH AND SURVIVAL OF THE MARINE SILVERSIDE, ODONTESTHES ARGENTINENSIS (PISCES, ATHERINIDAE), LARVAE

The effects of high stocking densities upon growth, survival, and biom ass production of the marine silverside larvae (Odontesthes argentinen sis) were studied under controlled laboratory conditions (temperature: 20 +/- 1 degrees C, salinity: 20 +/- 2 parts per thousand and photope riod: 13L-11D). Four stocking densities were tested: 15, 30, 45, and 9 0 larvae/l. Artemia nauplii were offered from the onset of feeding, an d the prey density was proportional to the stocking densities, achievi ng 20, 40, 60 and 120 nauplii/ml through the end of the experiment. La rvae were sampled on days 7, 14, 21, and 28 after hatching, for measur ements of their standard length and dry weight. There were not observe d any significative difference (P>0.05) in standard length and dry wei ght among treatments. The weight-specific growth rate averaged 0.11, a nd the survival percentage was high in all treatments, averaging 95% d uring the experiment. It was not observed signs of aggressive behavior (chasing and biting), suggesting the absence of cannibalism. Consider ing the satisfactory growth and survival of O. argentinensis larvae re ared in high stocking densities, the commercial culture of this specie s should be considered in the future.