The starfish Ophidiaster ophidianus is an Atlanto-Mediterranean species protected under the EU’s Habitat Directive. Despite the wide distribution and the current range of expansion of this thermophilic species in the northern Mediterranean Sea, nothing is known about its diet. Using field observations and δ13C and δ15N Stable Isotopes Analysis (SIA), the feeding habits of O. ophidianus were explored in two Mediterranean rocky reef areas located in the southern Tyrrhenian (Ustica Island, Italy) and the eastern Adriatic Sea (Molunat, Croatia). According to field observations, O. ophidianus preys mainly on crustose coralline algae (CCA) and the keratose sponge Ircinia variabilis in both areas. SIA confirmed the role of CCA in the diet of O. ophidianus but not that of the sponge and highlighted a not negligible role played by other sessile invertebrates, such us small gastropods and small sedentary worms. It was concluded that O. ophidianus is a facultative herbivore in Mediterranean rocky reefs.

中文翻译：

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结合目视观察和稳定同位素分析揭示嗜热海星 Ophidiaster ophidianus（棘皮动物：Asteroidea）的饮食

海星 Ophidiaster ophidianus 是一种受欧盟栖息地指令保护的大西洋-地中海物种。尽管这种嗜热物种在地中海北部分布广泛且目前范围扩大，但对其饮食一无所知。利用野外观测和 δ13C 和 δ15N 稳定同位素分析 (SIA)，在位于第勒尼安南部（意大利乌斯蒂卡岛）和亚得里亚海东部（克罗地亚莫鲁纳特）的两个地中海岩礁区探索了 O. ophidianus 的摄食习性. 根据实地观察，O. ophidianus 主要捕食这两个地区的壳珊瑚藻（CCA）和角化海绵 Ircinia variabilis。SIA 证实了 CCA 在 O 饮食中的作用。ophidianus 而不是海绵，并强调了其他无柄无脊椎动物（例如我们的小型腹足类动物和小型定居蠕虫）所发挥的不可忽视的作用。结论O. ophidianus是地中海岩礁中的兼性食草动物。