| Resumo: |
The growth and survival of juvenile red porgy, Pagrus pagrus, reared in captivity (mean body weigth 81.0 not equal to 37.24g), exposed to two different temperatures (18 degree and 22 degree C)and three salinities (21, 27 and 33 psu)during a 30 day period, were studied. Final survival rate was 100. in all treatments. The highest growth rate was reached at 18 degree C/33 psu with a value of 1.07 /day. There was an inverse trend in the growth rate between the two temperatures. Food consumption increased with the increase of salinity and temperature. The highest food consumption rate was 1.17. (18 degree C/33 psu). The relationships between protein efficiency ration (PER)and salinity were positive at 18 degree C and negative at 22 degree C. The highest values of PER were 1.31 and 1.29 at 18 degree C/33 psu and 22 degree C/21 psu, respectively. Condition factors for the same sets of temperature and salinity were 1.10 and 1.12, respectively. The highest oxygen consumption was observed at 21 psu for both 24h-fasted and fed red porgy. Although there were no statistical differences, the increase in oxygen consumption was longer in fed than in fasted fishes. These data suggest that different responses obtained on growth, could have been due to the interaction among multiples combinations of environmental factors and food.
Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales (ARGENTINA)
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