Competition and Habitat Shift in Two Sunfishes (Centrarchidae)
Competition and Habitat Shift in Two Sunfishes (Centrarchidae)
复制标题
两种翻车鱼（Centrarchidae）的竞争和栖息地转移
DOI：
10.2307/1936222
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发表时间：
1977
期刊：
影响因子：
4.8
通讯作者：
D. J. Hall
中科院分区：
文献类型：
--
作者：
E. Werner;D. J. Hall
蓝鳃太阳鱼（Lepomis macrochirus）在小池塘中以与植被相关的相对较大的猎物为食。然而，在绿色翻车鱼（L. cyanellus），它转移到捕食较小的，不太喜欢的猎物在开放的水柱。负责这种生境转变的机制进行了研究，实验限制两个物种，单独和一起，在均匀的补丁的首选栖息地（植被）。当被限制在一起的植被的绿色翻车鱼表现出较高的生存率，生长速度，并在胃中的食物量比蓝鳃。与绿色翻车鱼相比，蓝鳃太阳鱼以较小的食物为食，消耗更多的底栖猎物。同系物的存在并没有改变任何物种的食物习惯或绿色翻车鱼的生长速度相对于单独放养的物种。同源物的存在确实影响了蓝鳃金龟的生长速率。当这些物种被限制在植被中时，饮食中的重叠为70o，而在早期的一项研究中，允许栖息地分离时，重叠为44%。该绿色sunfi'sh是更多的是一个坐在等待捕食者，并能够利用更广泛的食物大小谱比蓝鳃。这导致了强烈的不对称的竞争功能，有利于植被中的绿色翻车鱼。然而，在开放的水柱中，食物大小的分布被截断，这为更有效地处理小食物的蓝鳃鱼提供了一个有竞争力的避难所。蓝鳃太阳鱼在栖息地利用上较为灵活，而绿色太阳鱼在栖息地利用上则更具侵略性且有限。与鲑鱼类栖息地变化的研究比较表明，所概述的竞争机制在鱼类群落中具有普遍意义。考虑栖息地结构，相关的食物大小分布，和物种形态之间的关系提供了一个框架，指定发生的栖息地变化，哪些物种的互动集将转移。
The bluegill sunfish (Lepomis macrochirus) in small ponds feeds on relatively large prey associated with the vegetation. However, in the presence of the green sunfish (L. cyanellus) it shifts to feeding on smaller, less preferred prey in the open water column. The mechanisms responsible for this habitat shift were examined by experimentally confining both species, alone and together, in homogeneous patches of the preferred habitat (vegetation). When confined together in the vegetation the green sunfish exhibited higher survivorship, growth rates, and amount of food in the stomachs than the bluegill. The bluegill fed on smaller items and consumed more benthic prey than did the green sunfish. The presence of the congener did not alter the food habits of either species or the growth rates of the green sunfish in relation to species stocked alone. Presence of the congener did affect the growth rates of the bluegill. Overlap in the diet was 70o when these species were confined to the vegetation as compared to 44% in an earlier study where habitat separation was permitted. The green sunfi'sh is more of a sit-and-wait predator and is able to utilize a wider food size spectrum than the bluegill. This results in a strong asymmetry in the competition function favoring the green sunfish in the vegetation. However, in the open water column the distribution of food sizes is truncated and this provides a competitive refuge for the bluegill which handles small foods more efficiently. The bluegill appears to be more flexible in its habitat use while the green sunfish is more aggressive and limited in the habitats utilized. Comparisons with studies of habitat shifts in salmonids suggest that the competitive mechanisms outlined are of general relevance in fish communities. Consideration of the relation between habitat structure, the correlated distribution of food sizes, and species morphology provides a framework for specifying the occurrence of habitat shifts and which species of the interactive set will shift.