ABSTRACT

The present study investigated the structure of the crab Clibanarius symmetricus (Randall, 1840) population found in a biogenic reef formed by the polychaete Sabellaria wilsoni Lana & Gruet, 1989 on the Amazonian coast. The population was sampled over a one-year cycle on a reef located in the mesolittoral zone of a sandy beach. The mean and maximum size of the crabs collected on the reef were smaller than those recorded in other tropical and subtropical coastal habitats, given that most of the specimens collected were immature (undetermined sex juveniles and sexually immature adults). Thaisella coronata (Lamarck, 1816) was the gastropod species whose shells were most occupied by the hermit crabs (70% of the specimens), although the smallest juveniles have used more the shells of other species. The results of the study suggest that C. symmetricus uses the reef as a nursery habitat, with bimonthly peaks in density that reflect recruitment periods. The sexually mature adults appear to use the reef only as a foraging area and, occasionally, as a refuge. The results demonstrated the importance these reefs on the population biology of this species and supports the need for more detailed monitoring studies and conservation actions for these habitats.

摘要

本研究调查了在1989年亚马逊沿岸多Sa Sabellaria wilsoni Lana＆Gruet形成的生物礁中发现的对称蟹Clibanarius（Randall，1840）种群的结构。在一个一年的周期内，在一个位于沙滩中间区域的礁石上对种群进行了采样。鉴于所收集的大多数标本不成熟（未定性性幼体和性不成熟成年），在礁石上收集的螃蟹的平均大小和最大大小均小于其他热带和亚热带沿海生境中记录的螃蟹。泰氏菌Lamarck（Lamarck，1816）是腹足动物，其壳被寄居蟹占据最多（占标本的70％），尽管最小的幼体更多地使用了其他物种的壳。研究结果表明，对称梭菌利用该礁作为苗圃栖息地，其密度每两个月出现一次峰值，反映出募集时期。性成熟的成年人似乎仅将珊瑚礁用作觅食区，偶尔用作避难所。结果证明了这些珊瑚礁对该物种的种群生物学的重要性，并支持对这些生境进行更详细的监测研究和保护行动的需要。