Reef Biology Research Group, Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
New Heaven Reef Conservation Program, Koh Tao, Suratthani, Thailand.
PLoS One. 2019 Apr 29;14(4):e0215063. doi: 10.1371/journal.pone.0215063. eCollection 2019.
Recent studies revealed that reef corals can eat large-sized pelagic and benthic animals in addition to small planktonic prey. As follow-up, we document natural ingestion of sea slugs by corals and investigate the role of sacoglossan sea slugs as possible prey items of scleractinian corals. Feeding trials were carried out using six sacoglossan species as prey, two each from the genera Costasiella, Elysia and Plakobranchus, and four free-living solitary corals (Danafungia scruposa, Fungia fungites, Pleuractis paumotensis and Heteropsammia cochlea) as predators. Trials were carried out under both in-situ and ex-situ conditions with the aim to observe ingestion and assess signs of prey consumption based on tissue loss of prey individuals over time. Significant differences were observed in both ingestion time and consumption state of prey between prey species, with three of them being ingested more rapidly and preferentially consumed over the others. Additionally, prey size was found to be a significant factor with larger prey (>12 mm) being ingested more slowly and rarely than smaller ones (<6 mm and 6-12 mm). Comparisons of consumption capability among predators showed no significant difference with all coral species showing similar preferences for prey species. While no specific mechanism of prey capture is proposed, we also document instances of kleptoparisitism and resuspension of prey items by wrasses. This study highlights the important distinction between opportunistic prey capture and true predation events.
最近的研究表明，珊瑚礁除了摄食小型浮游生物外，还可以摄食大型浮游和底栖动物。作为后续研究，我们记录了珊瑚礁自然摄食海蛞蝓的情况，并调查了舌形贝类海蛞蝓作为石珊瑚可能的猎物的作用。通过使用 6 种舌形贝类作为猎物进行摄食试验，每个属有 2 种，即 Costasiella、Elysia 和 Plakobranchus，以及 4 种自由生活的独居珊瑚（Danafungia scruposa、Fungia fungites、Pleuractis paumotensis 和 Heteropsammia cochlea）作为捕食者。试验分别在现场和场外条件下进行，目的是观察摄食情况，并根据猎物个体随时间的组织损失来评估猎物消耗的迹象。在猎物种类之间，观察到摄食时间和猎物消耗状态都存在显著差异，其中三种猎物被更快地摄食，并优先消耗，而其他三种则被较慢地消耗。此外，猎物大小被发现是一个重要因素，较大的猎物（>12 毫米）比较小的猎物（<6 毫米和 6-12 毫米）被摄入的速度更慢，也更少见。对捕食者的摄食能力进行比较，发现没有显著差异，所有珊瑚物种对猎物物种都表现出相似的偏好。虽然没有提出特定的捕食机制，但我们也记录了濑鱼通过盗食和重新悬浮猎物的情况。本研究强调了机会性猎物捕获和真正捕食事件之间的重要区别。
