Abstract
The larval development and growth of Plecoglossus altivelis are described based on a series of 268 reared specimens, ranging between 6.1 and 88mm standard length (SL). Development of morphological characters are described, with special reference to fin formation.
Transformation from the larval to juvenile stage was observed when fish attained about 27mm SL, 80 to 90 days after hatching. Fin rays completed segmentation at 33mm SL, and branch-ing at 42mm SL. Larval growth for 140 days was expressed by linear regression. Relative length of preanal length to total length changed drastically during yolk-sac larva to shortly before transformation, then became constant after 45mm TL. The importance of organogenesis and morphometric characters with respect to the ecological aspects of early life stages is discussed.
