松江鲈鱼繁殖习性的调查研究

ON THE BREEDING HABIT OF TRACHIDERMUS FASCIATUS HECKEL

本文对松江鲈鱼繁殖洄游、产卵场作了报道,对松江鲈鱼的胚胎发育和幼鱼形态作了描述和研究。 松江鲈鱼是一种降海产卵鱼类,在淡水中长成的亲鱼于每年十一月开始向河口洄游,进入浅海产卵。产卵盛期在二月下旬至三月上旬;黄海南部潮间带的蛎牙礁是松江鲈鱼的一个产卵场:卵产于牡蛎壳堆的洞穴顶部。雌鱼产卵后即离开洞穴移向沿岸近处开始索饵;雄鱼留在洞中有护卵的习性,护卵结束后亦离开产卵场开始索饵。 雌鱼的怀卵量是5100-12800粒。产出的卵具很强的粘性,结成团块,呈桔红、桔黄色或淡黄色,卵径为1.48-1.58毫米。受精卵在4-14℃水温条件下,约经26天孵化。在胚胎发育中见不到鳔的原基。刚孵化的仔鱼全长5.3-6.3毫米,偶可作垂直运动,但更多时间静卧水底。每年的4-6月,幼鱼溯河进入淡水成长。 为保护松江鲈鱼资源,应充分注意到它过河口繁殖的习性,应适时开放通海河道的水闸,以利于亲鱼降海产卵和幼鱼溯河进入淡水育肥。

Trachidermus fasciatus Heckel is a catadromous fish breeding in the coastal regionof the sea. In May and June the young fish migrates to the river where it grows for se-veral months and attains to maturity. In the later November the adult fishes begin todescend to the sea for spawning. A spawning ground is found in the south of the HuangHai, it is a small island, 5 knots away from the coast where the salinity varies from30‰ to 32‰ and the water temperatur about 4--5℃ in the breeding season. From themiddle of February to the middle of March, the male fish arrives to the spawning groundearlier than the female. Eggs are adhesive and laid in clumps attaching to oyster shellswhich form small caves in the big pile of shells on the oyster reef in the intertidal zone,the female leaves the cave as soon as the eggs being laid and the male fish remains totake care the eggs. The eggs hatch about in 26 days. The yolk sac of the fry absorbs in14 days. The young fishes begin to aggregate in the coastal region at the late April andreach to a peak in the middle of May.