Turf algae become the most abundant benthic group on coral reefs after mass coral bleaching. By defending feeding territories, damselfishes enhance the growth of turf algae in so-called algal farms and affect coral communities both directly and indirectly. We found several white scars (i.e., bite lesions) on massive Porites colonies around feeding territories. In this study, we examined the occurrence of white scars on corals and their function in coral–algal competition at the boundaries between algal farms of two damselfish species—the intensive farmer Stegastes nigricans, and the intermediate farmer S. lividus—and adjacent Porites corals for 3 years around Okinawa Island, Japan. White scars occurred on Porites colonies only adjacent to the territories of both damselfish species. Of the white scars on corals around S. nigricans territories, 73% of the area was covered by algae within 2 weeks, while the remaining was re-covered by Porites tissues. The coral–algal boundaries encroached further into areas of coral when the area of white scars were larger. These results suggest that both intensive and intermediate farmers bite adjacent Porites colonies causing white scars on corals, and expand their territories onto corals using algae-covered white scars as stepping stones.

在大规模珊瑚白化后，草坪藻类成为珊瑚礁上最丰富的底栖生物群。通过保护觅食区，雀鲷促进了所谓的藻类养殖场中草坪藻类的生长，并直接和间接地影响了珊瑚群落。我们在觅食区周围的大量Porites菌落上发现了几个白色疤痕（即咬伤）。在这项研究中，我们检查了珊瑚上白色疤痕的发生情况及其在两种雀鲷的藻类养殖场之间的珊瑚 - 藻类竞争中的功能-集约化养殖者Stegastes nigricans和中间养殖者S. lividus -以及相邻的Porites珊瑚在日本冲绳岛周围3年。出现白色疤痕Porites群落仅与两种雀鲷的领土相邻。S周围珊瑚上的白色疤痕。在 nigricans 的领土上，73% 的区域在 2 周内被藻类覆盖，而其余的则被Porites组织重新覆盖。当白色疤痕面积较大时，珊瑚 - 藻类边界进一步侵入珊瑚区域。这些结果表明，集约化和中级养殖者都会咬住相邻的Porites群落，从而在珊瑚上留下白色疤痕，并使用藻类覆盖的白色疤痕作为垫脚石将它们的领土扩展到珊瑚上。