1Miyako Station, National Center for Stock Enhancement, Fisheries Research Agency, Miyako, Iwate 027-0097, 2Department of Marine Bioscience, Faculty of Biotechnology, Fukui Prefectural University, Obama, Fukui 971-0003, Japan
In this study, the influence of Brazilian Artemia nauplii (BA) feeding on the occurrence of pseudoalbinism in two pleuronectid species (spotted halibut Verasper variegatus and brown sole Pseudopleuronectes herzensteini) was examined. BA were fed at six different periods from early larval stage (the stage at which they start to eat Artemia) to juvenile stage. Pseudoalbinism occurred at about 90-100% in the two pleuronectid species when BA was given before the flexion stage (E stage, spotted halibut; 10 mm TL, brown sole; 8 mm TL) suggesting that expression (or non-expression) of pseudoalbinism had been determined before the postflexion stage (F stage). For the prevention of pseudoalbinism, which possibly results in other deformities in relation to asymmetrical morphology, the stages before postflexion must be critically important in pleuronectid species.