长江口纹缟虾虎鱼的繁殖生物学特征

CHARACTERISTICS OF REPRODUCTIVE BIOLOGY OF TRIDENTIGER TRIGONOCEPHALUS AT THE YANGTZE RIVER ESTUARY

研究了长江口水域纹缟虾虎鱼的繁殖生物学。结果如下：（1）纹缟虾虎鱼雌雄亲鱼间形态学特征具有差异，肥满度分别为3.47±0.36与2.17±0.52，体长／体高、体长／头长、头长／眼径、头长／眼间距等比值存在极显著差异；（2）纹缟虾虎鱼产卵期为3-7月份，盛产期为4-6月份。绝对生殖力平均为12689.2粒，体长相对生殖力平均为206.9粒／mm；（3）纹缟虾虎鱼成熟的卵为球形，卵径0.482-0.606mm，卵中油球数量10-200个，精子较小，由圆形头部和细长尾部（鞭毛）两个部分组成；（4）纹缟虾虎鱼产卵受精一般在洞穴内进行，而且雄鱼具有护卵习性；（5）纹缟虾虎鱼受精卵呈梨形或者梭形，卵膜端具有由粘丝组成的附着盘，动物极靠近附着盘。纹缟虾虎鱼人工催产与自然繁殖时的受精率分别为78.58％与83.84％。在17-25℃范围内，纹缟虾虎鱼胚胎均能孵出仔鱼，随着水温上升发育速度加快，温度与孵化时间呈正相关关系，有效积温为3128.3h·℃。长江口水域生态环境变动可能对纹缟虾虎鱼繁殖及其资源量产生一定影响。

Characteristics of reproductive biology of Tridentiger trigonocephalus at the Yangtze estuary were studied. The results show as follows. （1）Morphological traits between male and female T. trigono-cephalus are different. Relative fatnesses of male and female T. trigonocephalus are 3.47±0.36 and 2.17±0.52,respectively. The ratio value of body length and body height, body length and head length, head length and eye diameter, head length and eye distance have significantly different between male and female. （2） T. trigonocephalus spawns in the summer from March to July, and main from April to June. The indi-vidual absolute fecundity is 12 689.2 eggs and body length relative fecundity is 206.9 eggs/mm. （3）The egg is circular and its diameter ranges from 0.482 to 0.606 mm. The sperm consists of round head with 0.98±0.12μm of the long diameter and 7.28±1.06μm flagellum. （4）T. trigonocephalus spawns in burrows and the nest will be protected by male fish. （5）The shape of fertilized eggs looks like a pear or a shuttle and there is an adhesive filament disc on the external egg-membrane of the animal pole. Fertilization rate under artificial and natural condition are 78.58% and 83.84% ,respectively. Normally,embryo can develop under the temperature condition from 17 to 25℃ and hatch time depending on water temperature. In theory the sum of effective temperature of embryonic development is 3 128.3h·℃. Reproductive biology and abundance of T. trigonocephalus may be affected by environment change of the Yangtze River estuary.