Research in recent years have provided rapid advances in biogeographic and taxonomic documentation of sea slugs around the world. However, efforts are lacking in surveying most coastlines and habitats in South-East Asia. Recent studies from the Gulf of Thailand have indicated that a wealth of unexplored sea slug diversity and ecology may be gained from an investigation of soft sediment habitats beyond the reef slopes. Additionally, the waters of Koh Tao have been found to host regionally high levels of sea slug diversity with several species awaiting taxonomic clarification. In this work the initial findings of an expanded survey effort from the waters around Koh Tao are provided, with the identity of two soft sediment-associated sacoglossan species in the family Plakobranchidae being investigated. By integrating morphological and molecular analyses, the species Plakobranchus noctisstellatussp. nov. and Elysia aowthaisp. nov. are described and species complexes surrounding Plakobranchus ocellatus van Hasselt, 1824 and Elysia japonica Eliot, 1913 are discussed. The topics of morphological variability and the cryptic species problem are also discussed.

中文翻译：

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来自泰国湾涛岛的软沉积物生境的斑节鱼科（天足目，Sacoglossa），描述了两个新物种

近年来的研究在全球海sea的生物地理和分类学文献方面提供了快速的进步。但是，在调查东南亚大多数海岸线和生境方面缺乏努力。来自泰国湾的最新研究表明，通过对礁石斜坡以外的软沉积物生境进行调查，可以获得大量未开发的海参多样性和生态学。此外，还发现涛岛（Koh Tao）的水域具有较高的海参多样性，其中有几种正在等待分类学的澄清。在这项工作中，我们提供了从涛岛附近水域扩大调查工作的初步发现，并调查了斑节鱼科中两种与沉积物相关的软aco科物种的身份。通过整合形态和分子分析，该物种Plakobranchus noctisstellatussp。十一月 和Elysia aowthaisp。十一月 描述了物种，并讨论了周围环境的物种分布，分别是Plakobranchus ocellatus van Hasselt（1824年）和Elysia japonica Eliot（1913年）。还讨论了形态变异性和隐物种问题。