Collection Record and Feeding Habits of Larval Spotted Halibut and Stone Flounder in Coastal Shallow Waters off Fukushima, the Pacific Coast of Eastern Japan

摘要

This report first describes the collection of a pelagic stage larva of spotted halibut Verasper variegatus (post-flexion F stage, 10.6 mm standard length) from the Pacific coast of eastern Japan. The larva was collected sympatrically with metamorphiclarvae of stone flounder Platichthys bicoloratus (F-G stages, 9.5-12.8 mm, n = 52) in coastal shallow waters off southern Fukushima Prefecture (6.0 m depth layer, within 16 m bottom depth) by otter trawling on 2 March 2011. The spotted halibut larva fedon a calanoid copepod (Centropages abdominalis), whereas stone flounder larvae mainly preyed on a poecilostomatoid copepod (Corycaeus sp.) and a few other prey items (harpacticoid copepod, bivalve larvae, and others). The sizes of preyed copepods (1.95 and 1.91 mm body length, n = 2) were larger in spotted halibut with larger mouth size (upper jaw length, UJL: 1.27 mm) than those observed in stone flounder (0.53-1.16 mm, mean 0.91 mm, n =139) with smaller mouth sizes (UJL: 0.79-1.17 mm).