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在 1 997年从美国引进的德克萨斯州选育品系斑点叉尾卵黄苗 ,经过几年的培育后 ,于2 0 0 0年在江苏省泰兴水产良种场首次繁殖。 3龄首次产卵的斑点叉尾产卵率较低 ,卵块较小。泰兴水产良种场对斑点叉尾的繁殖评估结果表明 ,产卵筒数量少和设置太深造成了上述较差的产卵结果。产卵筒的数量应从原来的 1∶1 0增加到 1∶2或 1∶3(产卵筒与雌亲鱼之比 )。产卵筒设置的深度应不得超过 60cm ,除非在水温激剧升高的情况下 ,则将产卵筒设置在水下≥ 1m。 3龄斑点叉尾繁殖的子代具有生长速度快、饲料转换率高和成活率高的特点。在 81天的投饲期间 ,五口重复试验地中斑点叉尾从 0 .0 8g长到 45 .9g ,平均饲料系数 1 .31 ,成活率为 85 .1 %。这些均高于 1 997年斑点叉尾亲本饲养的结果 ,在 1 49天的试验期间 ,斑点叉尾亲本只长到 72 g ,饲料系数为 1 .47。
Introduced from the United States in 1927, Texas yielded brooderm yolk seedlings, after several years of breeding, in 2001 in Taixing, Jiangsu Province, breeding ground for the first time breeding. The first instar larvae of Epinephelus ficus in the 3rd instar larvae had lower oviposition rate and smaller egg mass. Taixing aquaculture breeding field of Ictalurus punctatus assessment results show that the number of spawning tube less and set too deep caused the poor spawning results. The number of spawning tubes should be increased from 1: 1 0 to 1: 2 or 1: 3 (ratio of spawning tube to female parent). The depth of the spawning tube should not exceed 60cm unless the spawning tube is set ≥ 1m under water unless the water temperature is dramatically increased. Progeny of the 3rd instar catfish have the characteristics of fast growth, high feed conversion rate and high survival rate. During the 81-day feeding period, the median replicate Ictalurus punctatus in five replicates grew from 0.08g to 45.9g with an average feed coefficient of 1.31 and a survival rate of 85.1%. These were higher than those of the parent Piccochia pallidus in 1997. During the 49 days of the experiment, the channel catfish parent grew to 72 g with a feed factor of 1.47.