コチ

Platycephalus indicus (Linne) is a common platycephalid fish distributed throughout the warm Indo-Pacific region. In the vicinity of Fukuoka City, Kyushu, the spawning season seemed to extend from the end of June to the middle of July in 1953. The artificial insemination was carried out at Shikanoshima near Fukuoka City, on July 5, 1953, and the hatched larvae were reared in glass jars for about four days. The egg was colorless and buoyant, spherical in shape, 0.88-0.91 mm in diameter, with a single oil-globule which was slightly reddish or colorless and 0.19-0.21 mm in diameter. The hatching took place in about twenty-four hours at the water temperature 24-26℃. The newly hatched larva (Fig. M) was 1.78 mm in total length, with 29 (11+18) myotomes. The yolk was oval in shape, 0.61 mm in long axis, with a single oil-globule situated at the posterior end of it. Brown pigment cells were distributed on the yolk surface, larval fin, as well as on the body, and black ones on the head, trunk and on the oil-globule. The larva sixteen hours after hatched (Fig. N) was 2.71 mm in total length, with the dorsal fin steeply rose above the anus, where characteristic brown pigment cells were densly distributed. In sixty-four hours after hatching (Fig. P), the mouth opened and the eyes became black. In eighty-seven hours the larva attained 2.72 mm in total length, and the yolk was entirely consumed.