Breeding habits of the sciaenoid fish, Pseudosciaean manchurica, in the Korean seas

Abstract

1.Three famous fishing grounds of sciaenoid fish are found in the Yellow sea side of Korea (Table 1). Most of the fishermen believe that the fishes come to these grounds for spawning in spring.
2.The auther could obtain at southern two of these fishing grounds matured gonads from adult fishes and also many deposited pelagic eggs (Table 3).
3.The larvae were obtained by artificial fertilization. The egg is pelagic, spherical in .shape, measuring 1.41 to 1.56 mm. in diameter with a single oil-globule of 0.47 to 0.53 mm. in diameter. The colour of the oil-globule is light pinkish, though there are some individual differences. Very characteristic vermilion chromatophores appeor on the region of the heart, on the 17th myotome and on the surface of oil-globule of the embryo during the development of the larvae.
4.Besides melanophores, dark vermilion chromatophores are occurred between the eye and the otocyst, and on the 16th to 18th myotomes of the newly hatched larva measuring 3.3 to 3.5mm. in total length.
5.The time required for the hatching differs considerably by the water temperature. It took about 60 hours (water temp.13.1-20.7°C) 90 hours (11.8-19.9°C) and 82 hours (9.8-20.4°C) in our experiments. The surface water in natural is usually. 11-14°C, and it takes probably 5 days or more to hatch.
6.The number of ripe ovarian eggs is shown in table 4. It is presumed that adult fishes of 300mm. in body length, may have about 30, 000-70, 000 eggs and those of 350 mm, in body length, have about 100, 000 eggs.
7.In the breeding season, the yellow color of both sexes becomes more brilliant than in other seasons. In the spawning grounds the adult fishes are observed to leap up at the sea surfaces. A large shoal makei rhythmical loud noise as if in a chorus and it can be heared in the ship very nosily, sounding something like “ga: ga: ”.
8.This report is based mainely on the observations made in the years 1938 and 1941.