Habitat use and diet of two stream gobies of the genus Rhinogobius in south-western Shikoku, Japan
Habitat use and diet of two stream gobies of the genus Rhinogobius in south-western Shikoku, Japan
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日本四国西南部两种溪流虾虎鱼的栖息地利用和饮食
DOI：
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发表时间：
2001
影响因子：
2
通讯作者：
Y. Yanagisawa
中科院分区：
文献类型：
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作者：
Shinzaburo Sone;Mikio Inoue;Y. Yanagisawa
本文研究了两种同属的河流虾虎鱼(Rhinogobius sp. LD（大暗型）和CB（交叉带型）种间竞争对栖息地利用的重要性，方法如下：(i)研究了沿河道各物种对栖息地利用的差异；（ii）比较日本四国西南部岛满河支流异种和同属各物种的微生境利用和食性。Rhinogobius sp. LD主要使用来龙套穿过溪流。虽然CB在CB数量占主导地位的下游地区也主要使用膛线，但在LD数量占主导地位的上游地区，CB没有更多地使用膛线。微生境分析结果表明，在同栖和异栖群落中，LD和CB都偏好较低的底流速和较快的水流。然而，在同质谱中，LD比CB使用更粗的衬底和更快的电流，LD和CB使用的微生境条件范围都比异质谱更窄。食性分析表明，同域和异域食虫均偏好易漂移的雌蜂，表明它们采用伏击觅食方式。同域寄生菌对同样易漂移的leptoplebiids和chironomids有偏好，而同域寄生菌对这类无脊椎动物没有偏好。研究结果表明，陆生和陆生在争夺更好的取食生境，陆生在陆生的影响下改变了栖息地利用和觅食方式，流速和底物粗度是陆生和陆生栖息地分离的关键因素。
The importance of interspecific competition to habitat use by two congeneric stream gobies, Rhinogobius sp. LD (large-dark type) and CB (cross-band type), was studied by: (i) examining differences in habitat use by each species along the course of the stream; and (ii) comparing microhabitat use and the diet of each species between in allopatry and in sympatry in tributaries of the Shimanto River, south-western Shikoku, Japan. Rhinogobius sp. LD mainly used riffles through the course of the stream. Although CB also mainly used riffles in the lower reaches where CB was numerically dominant, the greater use of riffles by CB was not observed in upper reaches where LD was dominant. Microhabitat analysis revealed that both LD and CB preferred lower bottom velocity in faster current in both allopatry and sympatry. In sympatry, however, LD used coarser substrate and faster current than CB, and both LD and CB used narrower ranges of microhabitat conditions than in allopatry. Dietary analysis indicated that both allopatric and sympatric LD preferred baetids, which are apt to drift, suggesting they adopted ambush foraging. Allopatric CB preferred leptophlebiids and chironomids, which are also apt to drift, whereas sympatric CB did not prefer such invertebrates. Overall results of this study suggest that LD and CB compete for better feeding habitats, CB shift their habitat use and foraging mode under the influence of LD, and current velocity and substrate coarseness are key factors in their habitat segregation.