Larvae of two pleuronectiforms, Poecilopsetta plinthus (Poecilopsettidae) and Parabothus coarctatus (Bothidae), from southern Japan

Pelagic larvae of two pleuronectiforms, Poecilopsetta plinthus (Poecilopset tidae) and Parabothus coarctatus (Bothidae), are described and illustrated based on specimens collected off Tosa Bay., southern Japan. Postflexion lar vae (8.2-11.9 mm BL) of Poecilopsetta plinthus are characteristic in having a series of melanophore patches along the dorsal and anal fin bases and th e inner margins of the pterygiophore zones, and linear myoseptal pigmentati on also along the inner margins of the latter. Preflexion and flexion larva e (5.0-6.3 mm BL) of Parabothus coarctatus are distinctive in having the do rsal fin origin located level with the dorsal margin of the eye and seven e longated rays in the anterior part of that fin.