Effects of preferred prey density and temperature on feeding success and recent growth in larval mackerel of the southern Gulf of St. Lawrence
Effects of preferred prey density and temperature on feeding success and recent growth in larval mackerel of the southern Gulf of St. Lawrence
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DOI：
10.3354/meps07833
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发表时间：
2009-01-01
影响因子：
2.5
通讯作者：
Fortier, Louis
中科院分区：
文献类型：
--
作者：
Robert, Dominique;Castonguay, Martin;Fortier, Louis
我们评估了首选的猎物密度和温度的影响，从4个连续的年度队列（1997年至2000年）在圣劳伦斯湾南部的大西洋鲭鱼幼虫的喂养成功和最近的增长。个体摄食成功率（首选的猎物碳在幼虫长度的肠道内容物的线性回归残差）和最近的增长（最后3耳石增量的平均宽度）进行了测定，在每年的分层子样本的幼虫，不同的长度类。首选猎物的密度最好地解释了在第一次取食的幼虫（< 7毫米）的喂养成功和增长的变化，而温度是在较老的幼虫阶段的增长变化的主要来源。随着伪哲水蚤无节幼体密度的增加，早期仔鱼的摄食成功率和生长量增加，直至接近1 μ gC 1（-1）的饱足阈值。最近的增长线性增加，在幼虫后期的温度，没有任何迹象表明的最佳温度。这些结果表明，高丰度的首选猎物在发病的外源性喂养和相对温暖的温度在幼虫生长季节是重要的先决条件，出现一个强大的一年类大西洋鲭鱼。
We evaluated the effects of preferred prey density and temperature on the feeding success and recent growth of Atlantic mackerel larvae from 4 consecutive annual cohorts (1997 to 2000) in the southern Gulf of St. Lawrence. Individual feeding success (residuals of the linear regression of preferred prey carbon in the gut content on larval length) and recent growth (average width of last 3 otolith increments) were determined for a stratified subsample of larvae in each year and among different length classes. The density of preferred prey best explained variations in feeding success and growth in first-feeding larvae (< 7 mm), while temperature was the main source of growth variability during older larval stages. The feeding success and growth of early larvae increased with the density of Pseudocalanus sp. nauplii until a similar satiation threshold of 1 mu gC 1(-1). Recent growth increased linearly with temperature during the late larval stage, without any indication of a temperature optimum. These results suggest that high abundance of the preferred prey at the onset of exogenous feeding and relatively warm temperature during the larval growth season are important prerequisites for the emergence of a strong year class in Atlantic mackerel.