González-Gómez Roberto, Briones-Fourzán Patricia, Álvarez-Filip Lorenzo, Lozano-Álvarez Enrique
Instituto de Ciencias del Mar y Limnología, Unidad Académica de Sistemas Arrecifales, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, Mexico.
Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mexico, Ciudad de México, Mexico.
PeerJ. 2018 Jun 11;6:e4922. doi: 10.7717/peerj.4922. eCollection 2018.
Coral reefs sustain abundant and diverse macrocrustaceans that perform multiple ecological roles, but coral reefs are undergoing massive degradation that may be driving changes in the species composition and abundance of reef-associated macrocrustaceans. To provide insight into this issue, we used non-destructive visual census techniques to compare the diversity and abundance of conspicuous macrocrustaceans (i.e., those >1 cm and visible without disturbance) between two shallow Caribbean coral reefs similar in size (∼1.5 km in length) and close to each other, but one ("Limones") characterized by extensive stands of the branching coral , and the other ("Bonanza") dominated by macroalgae and relic coral skeletons and rubble (i.e., degraded). We also assessed the structural complexity of each reef and the percent cover of various benthic community components. Given the type of growth of , we expected to find a greater structural complexity, a higher cover of live coral, and a lower cover of macroalgae on Limones, and hence a more diverse and abundant macrocrustacean community on this reef compared with Bonanza. Overall, we identified 63 macrocrustacean species (61 Decapoda and two Stomatopoda). Contrary to our expectations, structural complexity did not differ significantly between the back-reef zones of these reefs but varied more broadly on Limones, and the diversity and abundance of macrocrustaceans were higher on Bonanza than on Limones despite live coral cover being higher on Limones and macroalgal cover higher on Bonanza. However, the use of various types of microhabitats by macrocrustaceans differed substantially between reefs. On both reefs, the dominant species were the clinging crab and the hermit crab , but the former was more abundant on Bonanza and the latter on Limones. occupied a diverse array of microhabitats but mostly coral rubble and relic skeletons, whereas was often, but not always, found associated with colonies of spp. A small commensal crab of , , was far more abundant on Limones, emerging as the main discriminant species between reefs. Our results suggest that local diversity and abundance of reef-associated macrocrustaceans are partially modulated by habitat degradation, the diversity of microhabitat types, and the establishment of different commensal associations rather than by structural complexity alone.
珊瑚礁养育着丰富多样的大型甲壳类动物，这些动物发挥着多种生态作用，但珊瑚礁正在经历大规模退化，这可能正在推动与珊瑚礁相关的大型甲壳类动物的物种组成和数量发生变化。为了深入了解这个问题，我们使用了非破坏性视觉普查技术，比较了两个大小相似（长度约1.5公里）且彼此相邻的加勒比浅海珊瑚礁之间明显的大型甲壳类动物（即那些大于1厘米且在不受干扰时可见的动物）的多样性和数量。其中一个珊瑚礁（“利蒙内斯”）以大片分支珊瑚为特征，另一个（“博南扎”）则以大型藻类以及残留的珊瑚骨骼和碎石为主（即已退化）。我们还评估了每个珊瑚礁的结构复杂性以及各种底栖生物群落组成部分的覆盖百分比。鉴于 的生长类型，我们预计在利蒙内斯会发现更高的结构复杂性、更高的活珊瑚覆盖率以及更低的大型藻类覆盖率，因此与博南扎相比，该珊瑚礁上的大型甲壳类动物群落会更加多样和丰富。总体而言，我们识别出了63种大型甲壳类动物（61种十足目和2种口足目）。与我们的预期相反，这些珊瑚礁后礁区域的结构复杂性并无显著差异，但在利蒙内斯变化范围更大，而且尽管利蒙内斯的活珊瑚覆盖率更高，博南扎的大型藻类覆盖率更高，但博南扎上大型甲壳类动物的多样性和数量却比利蒙内斯更高。然而，不同珊瑚礁上大型甲壳类动物对各种微生境类型的利用存在很大差异。在这两个珊瑚礁上，优势物种都是寄居蟹 和椰子蟹 ，但前者在博南扎更为丰富，后者在利蒙内斯更为丰富。 占据了各种各样的微生境，但主要是珊瑚碎石和残留骨骼，而 则经常（但并非总是）与 属的群体相关联。一种小型共生蟹 在利蒙内斯的数量要多得多，成为区分不同珊瑚礁的主要判别物种。我们的研究结果表明，与珊瑚礁相关的大型甲壳类动物的局部多样性和数量部分受到栖息地退化、微生境类型的多样性以及不同共生关系的建立的调节，而不仅仅是由结构复杂性决定。
