Thermal Optima for the Culture of Juvenile Summer Flounder, Paralichthys dentatus

摘要

Summer flounder, Paralichthys dentatus, aquaculture has shown promise over the recent past and a considerable body of knowledge is amassing for this species of flatfish. Even with the amassing data, basic information on environmental parameter rangesto maintain in indoor culture systems is still lacking. Therefore, the current study was undertaken to elucidate a temperature range that may be best suited for juvenile summer flounder production in indoor rccirculating aquaculture. A 10-week study wasdesigned to address 19, 24 and 29 deg C as potential temperatures for the culture of summer flounder. Fish averaging 9.5 g initial weight were stocked into triplicate 20-L aquaria per treatment after conditioning to their respective temperatures for 1 week. Fish were fed to apparent satiation twice daily a 50% crude protein fingerling diet and weighed every 2 weeks to assess growth rates. Juvenile summer flounder grew better at 24 and 29 deg C (167 and 197% increase initial weight, respectively) than at19 deg C (97% increase in initial weight) with increased individual fish variation within a treatment as temperature increased above 19 deg C. Feed efficiency was greatest at 24 and 29 deg C (0.65 and 0.57, respectively), hut survival decreased at temperatures ahove 19 deg C (93, 60 and 57% for 19, 24 and 29 deg C, respectively). There was no effect of temperature on the hepatosomatic index or interior muscle ratio, but the finray muscle ratio was slightly elevated when flounder were cultured at 29 degC. The lipid content of the finray muscle and liver also increased at 29 deg C. Therefore, 24 deg C appears to be the best culture temperature i'or summer flounder with respect to growth rates and efficiency, but survival and homogeneity of flounder maybe lowered at temperatures above 19 deg C.