LARVAL MORPHOMETRY OF THE JAPANESE FLOUNDER, PARALICHTHYS-OLIVACEUS

The larval development of the Japanese flounder, Paralichthys olivaceu s, was surveyed using two types of morphometric analyses, modified all ometry and polar coordinate analysis by principal component analysis ( PCA). In the former, centroid size was used as a growth index instead of total length (TL), such enabling the determination of more detailed changes in each character than ordinary allometry based upon TL. Pola r coordinate analysis disclosed two remarkable inflexions during the l arval development of P. olivaceus. Postlarvae of P. olivaceus were fou nd to undergo four developmental phases. From the point of view of met amorphosis, the phases were named drifting larva, premetamorphic larva , metamorphic larva and postmetamorphic larva, respectively. These pha ses were also tested by other characters related to flounder metamorph osis.