ANALYSIS OF MICROHABITAT STRUCTURE OF CORAL REEF FISHES RELATED TO GEOMORPHOROGICAL FEATURES

在冲绳石崎岛白鹤礁浅层珊瑚护城河（<3m，约6ha）上，利用影像分析软件处理的数字化航拍照片作为野外地图，对豆娘鱼的微生境利用进行了野外观测。从照片中提取的颜色与底栖生物景观相同，与雀鲷（海葵鱼）的确切微栖息地相同，这些照片被认为是鱼类的潜在栖息地。利用种群密度数据在计算机上分析了潜在生境的几何特征。同样地，从照片中提取了豆娘鱼所使用的所有底栖景观，并分析了研究点中所有豆娘鱼物种丰富度和多样性较高的微生境特征。海葵鱼的潜在栖息地为可在航拍图像上识别的三维珊瑚礁，样方中海葵鱼的种群密度与样方中潜在栖息地的总面积和总周长相关。这表明海葵鱼在三维珊瑚礁聚集的地方很丰富。样方内雀鲷物种丰富度和丰度也与样方内三维珊瑚礁总面积相关。在航拍照片上可识别的三维珊瑚礁聚集总面积可作为浅层珊瑚礁护城河物种丰富度和丰度的有效指标。

Field observations were conducted to analyze microhabitat use by damselfishes on a shallow coral moat (<3m, about 6ha) of Shiraho reef, Ishigaki Island, Okinawa, using digitalized aerial photographs processed with image analysis software as field maps. The color same as the benthic landscapes that were identical to exact microhabitats of a damselfish (anemonefish) were extracted from the photographs, which were recognized as the potential habitats of the fish. Geometrical features of the potential habitats were analyzed on a computer related to population density data of the fish. Similarly, all benthic landscapes used by damselfishes were extracted from the photographs, and features of their microhabitats with higher species richness and diversity of all damselfish species in study sites were analyzed.The potential habitats for the anemonefish were 3 dimensional reefs that could be recognized on the aerial photographs, and population density of the fish in a quadrat was correlated with total aria and total perimeter of the potential habitats in the quadrat. This suggests that the anemonefish are abundant in a place where 3 D reefs are aggregated. Damselfish species richness and abundance in a quadrat were also correlated to the total area of 3 D reefs in the quadrat. Total area of aggregated 3 D reefs that can be recognized on aerial photographs may be an effective indicator of high species richness and abundance in a shallow coral reef moat.