Influence of feeding periods of Brazilian Artemia during larval development of hatchery-reared flounder Paralichthys olivaceus on the appearance of albinism.

The influence of feeding periods of Brazilian Artemia salina nauplii on the appearance of albinism in juvenile flounder P. olivaceus was examined. Flounder larvae were initially reared with only rotifer Brachionus plicatilis to 5.57mm TL. Artemia salina nauplii were given to floun-der larvae on four different feeding periods from 5.57mm to about 16.1-18.7mm TL (complete metamorphosis). Rotifer was also used for the diet. Albinism on juvenile flounder (16.1-18.7mm TL) were classified based on their albinic portions. Feeding with Artemia from the earlier stages (5.57mm and 8.67-8.86mm TL) resulted in the especially high frequency occurrences of albinism 97.0-97.6%, and the albinic portions extended over almost all of the ocular side. Feeding with Artemia from later stages (10.21-10.43mm and 12.98-13.23mm TL) reduced those of albinism (83.5-82.9% and 22.9-24.1% respectively), and their ablinic portions restricted to rather limited part of ocular side. These results suggested the close relationship between albinism oc-currence of juvenile flounder and giving a particular kind of food during larval stage.