Pond nursery production of southern flounder (Paralichthys lethostigma) and weaning to commercial diets

Southern flounder (Paralichthys lethostigma) were spawned during March, 199 7, and 4-day post hatch larvae (mean TL = 2.0 +/- 0.1 mm) were stocked into two 0.1 ha ponds at a density of 74 m(-2). At stocking, water temperature was 20 degrees C and salinity 30 ppt. No supplemental feed provided and fis h were harvested after 74 days of culture (June 9). A total of 5587 fingerl ings were harvested from the ponds and average survival was 3.8%. Mean fish length in one pond was 37 +/- 7 mm (23-54 mm) while mean size of fish in t he other pond was 55 +/- 8 mm (38-80 mm). Incidence of pseudoalbinism was e xtremely low (< 1%) in both ponds. The 78-day old fish which were harvested from the ponds were converted to dry diets in 14 days. Average survival du ring the transition period was 80.4%. In contrast, fish harvested, during a previous pond nursery study, at an age of 220 days required 106 days to tr ansition to dry feeds. Survival during transition averaging 58.2%. (C) 1999 Elsevier Science B.V. All rights reserved.