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首页> 外文期刊>North American Journal of Fisheries Management >Survival and growth of intensively reared large walleye fingerlings and extensively reared small fingerlings stocked concurrently in small lakes
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Survival and growth of intensively reared large walleye fingerlings and extensively reared small fingerlings stocked concurrently in small lakes

机译：在小湖中同时放养的大面积大眼鲷鱼种和大养小鱼种的生存和生长

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摘要

Size of walleyes Stizostedion vitreum at the time of stocking is thought to play a key role in determining the success of stocking programs. Because starvation and predation risk are size-dependent processes, fingerlings stocked at larger sizes are expected to survive better than fingerlings stocked at smaller sizes. However, large fingerlings often require different culture techniques that make them more expensive to produce. Therefore, large fingerlings should only be used if returns are high enough to offset costs. We evaluated the relative success of two sizes of stocked walleye fingerlings in four lakes in New York State. For four consecutive years (1993- 1996), each lake was stocked with equal densities (50 fish/ha) of small (30-50-mm), extensively reared pond fingerlings in June and large (120-140-mm), intensively reared fall fingerlings in September. In October, we electrofished each lake to determine growth and survival of stocked fingerlings. Despite being stocked at a much later date, average catch rates of fall fingerlings were not significantly higher than pond fingerlings. The relative survival of fingerlings varied among lakes, and in two lakes survival of fall fingerlings was actually lower than pond fingerlings. Similar patterns of survival were observed for walleyes caught as yearlings and for catches of Older walleyes in gill nets. Fall fingerlings were also significantly smaller than pond fingerlings at the end of the first growing season, and this disparity persisted 3 years after stocking. Overall, our results indicate that relative success of the two sizes of stocked walleyes varies among lakes and that stocking large walleye fingerlings will not necessarily lead to higher returns.
机译：放养时，角膜眼玻璃体的大小被认为对决定放养程序的成功起关键作用。由于饥饿和捕食风险是与大小有关的过程，因此，放养较大尺寸的鱼种比放宽尺寸的鱼种会更好地存活。但是，大型鱼种经常需要不同的养殖技术，这会使它们的生产成本更高。因此，只有在收益足够高以抵消成本的情况下才应使用大型鱼种。我们评估了纽约州四个湖泊中两种规格的放养的角膜白种鱼的相对成功率。连续四年（1993年至1996年），每个湖都放养了密度相同的鱼类（每公顷50条鱼），其中小型（30-50毫米），在六月广泛养殖的鱼种和大型（120-140毫米）在9月饲养了秋天的鱼种。在十月份，我们对每个湖进行了电钓，以确定鱼种的生长和存活。尽管在较晚的日期进行放养，但秋天鱼种的平均捕获率并未明显高于池塘鱼种。鱼种的相对存活率在湖泊之间有所不同，在两个湖泊中，秋天鱼种的存活率实际上低于池塘鱼种。一岁捕获的角膜白斑和g网捕获的老角膜白斑也观察到相似的生存模式。在第一个生长季节结束时，秋天的鱼种也比池塘的鱼种小得多，放养3年后，这种差距持续存在。总的来说，我们的结果表明，在湖泊之间放养两种尺寸的角膜白斑的相对成功率不同，并且放养大型角膜白斑鱼种不一定会带来更高的回报。

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