Habitat choice and recruitment of tropical fishes on temperate coasts of Japan
Habitat choice and recruitment of tropical fishes on temperate coasts of Japan
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日本温带海岸热带鱼的栖息地选择和招募
DOI：
10.1007/s10641-012-0106-2
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发表时间：
2013
影响因子：
1.4
通讯作者：
Yamaoka K
中科院分区：
文献类型：
--
作者：
Soeparno;Nakamura Y;Yamaoka K
随着海水表面温度的上升，热带珊瑚礁珊瑚在日本温带海岸扩张，在这些珊瑚栖息地中经常观察到许多热带鱼幼鱼。本研究探讨了近海热带鱼幼虫如何在日本温带海岸找到珊瑚栖息地。2009年7月至2011年10月，在有珊瑚生境和无珊瑚生境（岩石生境）上以两层距离（每种生境类型之间的距离分别为6 km和500 m）对沉降期幼虫进行取样。不论距离远近，珊瑚为主生境的幼虫丰度均显著高于岩石生境，说明珊瑚生境对近海热带鱼幼虫具有较强的吸引力。在水下目视调查中，两个地点的珊瑚生境中Chaetodontidae和Pomacentridae幼鱼的数量都高于岩石生境，并且实验室生境选择实验表明，这些幼鱼对珊瑚的偏好高于岩石生境。在珊瑚生境和岩石生境中，毛蚶幼鱼的密度没有差异，幼虫在生境选择实验中也没有表现出对基质的偏好。这些观察结果表明，定居时的栖息地选择可能解释了两种栖息地之间热带鱼定居模式的差异。综上所述，我们的研究结果表明，大多数热带鱼幼虫在约0.5 km的范围内定居在它们的定居海岸，并且它们可能在到达珊瑚礁后找到珊瑚栖息地。此外，温带海岸珊瑚栖息地的扩张将导致与珊瑚相关的热带鱼数量的增加，并将改变温带海岸鱼类的组合结构。
Tropical reef corals are expanding on Japanese temperate coasts in response to rising sea surface temperatures, and many tropical fish juveniles have been observed routinely in these coral habitats. The present study explored how offshore tropical fish larvae locate coral habitat on the temperate coasts of Japan. Settlement-stage larvae were sampled between July and October 2009–2011 with light traps anchored on coral-replete and coral-free habitats (rocky habitats) at two-level distance (distance between each habitat type was 6 km and 500 m, respectively). Larval abundance was significantly higher on the coral-dominated habitat than that on the rocky habitat at both short and long distance sites, suggesting that coral habitats attract offshore tropical fish larvae. In underwater visual survey, Chaetodontidae and Pomacentridae juveniles were more abundant in coral habitats than in rocky habitats at both the sites, and a laboratory habitat choice experiment demonstrated that these larvae showed a preference for corals rather than rocks. In contrast, densities of juvenile Mullidae did not differ between the coral and rocky habitats, and the larvae did not show a substrate preference in the habitat choice experiment. These observations suggest that habitat choice at settlement possibly accounts for the differences in settlement patterns of tropical fishes between the two habitats. Taken together, our results showed that most tropical fish larvae colonize their settlement coast at a scale of ~0.5 km, and that they may locate coral habitats after reaching a reef. Moreover, the results suggest that coral habitat expansion on temperate coasts will lead to an increase in coral-associated tropical fishes and will change assemblage structures of fishes on temperate coasts.