Morphological and Functional Development of Japanese Flounder in Early Life Stage

Abstract

Larval rearing and morphological observations were performed to qualify the biological characters in the early life stage of Japanese flounder Paralichthys olivaceus. Larval development from hatching to metamorphosis was described in detail including squamation and fin development. Transformation from larvae to juveniles occurred between from 11.0 mm to 12.5 mm SL (SL), and eye migration was completed from 10.5 mm SL. The eye migration was assumed to be completed when larvae were more than 17.0 mm SL. Swimming speed of larvae was recorded at about 4.0 mm/s for larval stage, and increased prior to morphological transition. The change of morphometric characters was closely related with the developmental changes of transformation and eye migration, and with behavioral and ecological changes as well. It was consequently suggested that morphological developments of various organs were implicated in the functional significance and also the shift of the life pattern of this species. © 1986, The Japanese Society of Fisheries Science. All rights reserved.