Bähr Susanne, van der Meij Sancia E T, Terraneo Tullia I, Xu Tao, Benzoni Francesca
Marine Science Program Biological and Environmental Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia.
KAUST Red Sea Research Center King Abdullah University of Science and Technology Thuwal Saudi Arabia.
Ecol Evol. 2023 May 11;13(5):e10051. doi: 10.1002/ece3.10051. eCollection 2023 May.
Coral reefs accommodate a myriad of species, many of which live in association with a host organism. Decapod crustaceans make up a large part of this associated fauna on coral reefs. Among these, cryptochirid crabs are obligately associated with scleractinian corals, in which they create dwellings where they permanently reside. These gall crabs show various levels of host specificity, with the majority of cryptochirids inhabiting a specific coral genus or species. Here, we report the first records of gall crabs living in association with two different species in the Red Sea. Crescent-shaped dwellings were observed in and a sp. in situ, and colonies with crabs were collected for further study in the laboratory. Using a combination of morphology and DNA barcoding, the crabs were identified as belonging to , a genus only known to inhabit Agariciidae corals. The coral skeleton was bleached and studied under a stereo microscope, which revealed that the corals overgrew adjoining agariciid colonies. We hypothesize that the gall crab originally settled on , its primary host of choice. Due to coral interspecific competition the colony overgrew the adjacent colonies, resulting in a secondary and never before reported association of with . These findings suggest that cryptochirid crabs can adapt to the new microenvironment provided by a different coral host and survive competition for space on coral reefs.
珊瑚礁容纳了无数物种，其中许多与宿主生物共生。十足目甲壳类动物构成了珊瑚礁上这种共生动物群的很大一部分。其中，隐螯蟹与石珊瑚有着必然的共生关系，它们在石珊瑚中建造居所并永久居住。这些瘿蟹表现出不同程度的宿主特异性，大多数隐螯蟹栖息在特定的珊瑚属或种中。在此，我们报告了红海地区瘿蟹与两种不同珊瑚物种共生的首次记录。在原位观察到了新月形的居所，以及一种石芝珊瑚属物种，并且收集了带有螃蟹的珊瑚群体以便在实验室进行进一步研究。通过形态学和DNA条形码技术相结合，这些螃蟹被鉴定为属于隐螯蟹属，该属仅已知栖息于鹿角珊瑚科珊瑚中。对珊瑚骨骼进行漂白并在体视显微镜下进行研究，结果显示石芝珊瑚属珊瑚覆盖了相邻的鹿角珊瑚科珊瑚群体。我们推测，瘿蟹最初定居在其首选的主要宿主鹿角珊瑚科珊瑚上。由于珊瑚种间竞争，石芝珊瑚属珊瑚群体覆盖了相邻的鹿角珊瑚科珊瑚群体，导致了隐螯蟹与石芝珊瑚属珊瑚之间一种前所未有的次生共生关系。这些发现表明，隐螯蟹能够适应由不同珊瑚宿主提供的新微环境，并在珊瑚礁上的空间竞争中生存下来。
