台灣新紀錄－－斑帶圓捲螺Volvatella vigourouxi（Montrouzier, 1861）（後鰓亞綱：囊舌目：圓捲螺科）之形態與行為描述

A Description of Volvatella vigourouxi (Montrouzier, 1861) (Opisthobranchia: Sacoglossa: Volvatellidae) as a Snail Newly Recorded to Taiwan with Special References to Its Behaviors

本文報導斑帶圓捲螺Volvatella vigourouxi（Montrouzier, 1861）為台灣軟體動物囊舌目（Sacoglossa）的新紀錄科（圓捲螺科，Volvatellidae）、屬（圓捲螺屬，Volvatella）及種外，並描述斑帶圓捲螺發現之棲地及其形態與攝食、交配、防禦等生態行為。高雄柴山珊瑚礁海岸之斑帶圓捲螺棲息於低潮帶針葉蕨藻Caulerpa sertularioides（Gmelin）Howe，1905的藻叢間，體長介於4.97-9.31 mm間，以針葉蕨藻為食。交配時個體長小於6 mm扮演之角色為雄性，會爬至個體長大於7 mm之雌性背部右側進行交配。當個體受到攻擊時，會分泌出白色黏液，並迅速逃離。 This paper describes Volvatella vigourouxi (Montrouzier, 1861) (Opisthobranchia: Sacoglossa: Volvatellidae) as a species newly recorded to Taiwan. It was a small snail with body lengths of 4.97 mm to 9.31 mm. It inhabited on coral reefs in the coastal intertidal zone of Chai-shan, Kaohsiung and fed on green algae, Caulerpa sertularioides (Gmelin) Howe, 1905. Although it was a hermaphroditic animal, testes became mature at earlier ages than ovaries, so that the sizes of individuals less than 6 mm were found to be males, and larger than 7 mm were females. In copulation the small male mounted on the top of the large female. When attacked, it secreted white mucus and crawled away.