ミミズハゼ属

Luciogobius guttatus Gill is a small, elongate yellowish goby, living under the stones lying on the estuarine muddy sand beach. It is distributed widely in North China, Korea, and Japan (Fig. 1). As is already reported by D. S. Jordan and J. 0. Snyder (1901) and I. Tomiyama (1936), this fish shows remarkable individual variety in the body form, coloration, and number of fin-rays as well as vertebrae. The spawning season extends from January to May in the vicinity of Fukuoka City, Kyushu. The number of ovarian eggs of one female fish were enumerated from 360 to 1,671 (Table 1). The breeding room is constructed as flat burrow under the stone where the parent fish live (Fig. 2 and Fig. 3). The female parent fish deposits eggs on the under side of the stone roof, the eggs hanging down from the stone in one layer mass. The number of the eggs of one sheet were enumerated 784 and 960 in two cases. When the spawning act finish the female parent fish leaves the breeding room, while the male parent guards over the eggs until they hatch. The spawned egg is club shaped, measuring 2.5 mm in long axis and 0.7 mm in short axis, with a shallow depression encircling near the top of egg and a bundle of adhesive filaments at the basal end (Fig. 4). The incubation-period lasted about 10 days at the temperature from 15℃ to 20℃ (Fig. 5). The newly hatched larva was 3.5 mm in total length. The larvae, 7～22 mm (Fig. 6). in total length, were found swimming in the middle of the water near shore, feeding on planktonic copepods. When the larvae attained over 15mm in total length, they approach the beach and enter into the bottom life there (Table 2). The specimens collected from Kyushu show that the goby grow to 30～48 mm in total length in a year, 48～63 mm in two years, and over 63 mm in three years. Some individuals seems to become mature in a year at 33 mm in total length in both sexes.