Otolith–fish size relationship in juvenile gag (Mycteroperca microlepis) of the eastern Gulf of Mexico: a comparison of growth rates between laboratory and field populations
Otolith–fish size relationship in juvenile gag (Mycteroperca microlepis) of the eastern Gulf of Mexico: a comparison of growth rates between laboratory and field populations
复制标题
墨西哥湾东部幼鱼（Mycteroperca microlepis）的耳石与鱼大小关系：实验室和野外种群生长率的比较
DOI：
10.1016/s0165-7836(02)00171-6
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发表时间：
2003
影响因子：
2.4
通讯作者：
C. Koenig
中科院分区：
文献类型：
--
作者：
A. Strelcheck;G. Fitzhugh;F. Coleman;C. Koenig
在这项研究中，我们对来自墨西哥湾东部的野生捕获的幼鱼进行了实验，以评估食物可获得性对体细胞生长和耳石生长的影响。在两种不同的食物水平下喂养幼鱼，直到所有的鱼都达到相似的大小。我们发现，食物供应对增长率有很大影响。然而，我们也发现这表现在不同的耳石大小上。也就是说，生长较慢的Gag比同等大小的生长较快的Gag有更大、更重的耳石；这是以前在各种鱼类中观察到的实验结果。我们希望将这些实验结果应用于野外捕获的Gag，因为我们的初步观察表明，至少在幼年早期，来自佛罗里达州西海岸更南纬的Gag比来自更北纬的Gag更大。将这些关系应用于区域野外种群，我们发现，使用耳石鱼大小替代生长指标，来自较北纬的幼鱼似乎比来自南纬的幼鱼生长得更快。然而，对鱼类长度-年龄关系的研究表明，不同地区的幼鱼Gag生长率没有显著差异。这些结果与来自南部纬度的较大体型的Gag生长速度更快的预期相反，表明产卵时间和栖息地质量等其他因素可能解释了地区大小的差异。
In this study, we conducted experiments on wild-caught juvenile gag Mycteroperca microlepis from the eastern Gulf of Mexico to evaluate the effect of food availability on somatic growth and otolith growth. Juveniles were fed at two different food levels until all fish attained similar sizes. We found that food availability significantly affected growth rates. However, we also found that this manifested itself in differential otolith size. That is, slower-growing gag had larger, heavier otoliths than equal-sized faster-growing gag; an experimental result that has been observed previously among various fish species. We wanted to apply these experimental results to field-caught gag because our initial observations indicated that gag from more southern latitudes along Florida’s west coast were larger than gag from more northern latitudes, at least during the early juvenile period. Applying these relationships to regional field populations, we found that juvenile gag from the more northern latitudes appeared to grow faster than those from southern latitudes, using an otolith–fish size proxy for growth. However, examination of fish length–age relationships revealed that juvenile gag growth rates were not significantly different between regions. These results are contrary to the expectation that larger-sized gag from southern latitudes are growing faster, and suggests that other factors, such as spawning time and habitat quality may explain regional size differences.