Commercial producers raising centrarchids in Arkansas routinely report winter mortality. Juvenile centrarchids are susceptible to harsh winter conditions. The Coppernose Bluegill Lepomis macrochirus purpurescens is a popular sport fish for recreational fishing, and there are no recommended best management practices for winter feeding of this species. An outdoor trial was conducted to investigate the effect of different feeding regimens on performance of Coppernose Bluegill in the winter of 2014–2015. Four feeding regimens were implemented that included feeding twice per week (2×/week), once per week (1×/week), twice per month (2×/month), or once per month (1×/month). Twenty-five Coppernose Bluegill (initial weight = 2.59 ± 0.19 g) were stocked per tank (16 tanks, 4 replicates). Temperatures ranged from 0°C to 16°C during the trial. After 95 d, there were no differences (P > 0.05) in final weight or weight loss. Fish that were fed 2×/week or 1×/week had higher survival (P < 0.05) than those fed 2×/month or 1×/month. Fatty acid profiles of initial fish were distinctly different from the postwinter profiles of fed fish, although winter feeding frequency did not appear to influence fatty acid profiles in Coppernose Bluegill. Levels of saturates were higher in initial fish than in postwinter fish. The monounsaturated fatty acids 16:1 and 18:1(n-9) were higher in initial fish than in postwinter fish. Initial fish contained lower levels of 18:2(n-6), 20:4, and 22:6(n-3) than postwinter fish. Total polyunsaturated fatty acids (PUFAs) and n-3 and n-6 levels were also lower in initial fish than in postwinter fish, while the ratio of n-6/n-3 fatty acids did not differ significantly among initial and postwinter fed fish. Data indicate that (1) overwintering and infrequently fed Coppernose Bluegill preferentially conserve PUFAs and (2) feeding 1 × /week or 2 × /week may be a beneficial strategy for sport fish producers to increase survival of Coppernose Bluegill during the winter in temperate regions of the USA.

中文翻译：

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使用不同饲养方案在室外水箱中培养的越冬幼年铜鼻蓝鳃 Lepomis macrochirus purpurescens 的体重减轻、存活和脂肪酸组成

在阿肯色州饲养中心动物的商业生产者经常报告冬季死亡率。幼年的centrarchids容易受到严酷的冬季条件的影响。Coppernose Bluegill Lepomis macrochirus purpurescens是一种流行的休闲钓鱼运动鱼，对于该物种的冬季喂养没有推荐的最佳管理做法。在 2014-2015 年冬季进行了一项户外试验，以调查不同喂养方案对铜鼻蓝鳃鱼性能的影响。实施了四种喂养方案，包括每周喂食两次（2×/周）、每周一次（1×/周）、每月两次（2×/月）或每月一次（1×/月）。每缸放养 25 只铜鼻蓝鳃鱼（初始重量 = 2.59 ± 0.19 g）（16 缸，4 次重复）。试验期间温度范围为 0°C 至 16°C。 95 d后，最终体重或体重减轻无差异（P > 0.05）。喂食 2 次/周或 1 次/周的鱼存活率更高（P < 0.05) 比喂食 2 次/月或 1 次/月的那些。初始鱼的脂肪酸谱与喂食鱼的冬季后的脂肪酸谱明显不同，尽管冬季喂食频率似乎不会影响铜鼻蓝鳃鱼的脂肪酸谱。初始鱼的饱和物水平高于冬后鱼。初始鱼中的单不饱和脂肪酸 16:1 和 18:1(n-9) 高于冬后鱼。与越冬后的鱼相比，初始鱼的 18:2(n-6)、20:4 和 22:6(n-3) 水平较低。初始鱼的总多不饱和脂肪酸 (PUFA) 和 n-3 和 n-6 水平也低于冬季后的鱼，而初始和冬季后的鱼中 n-6/n-3 脂肪酸的比例没有显着差异.