On the Plakobranchidae (Gastropoda, Sacoglossa) from soft sediment habitats of Koh Tao, Gulf of Thailand, with descriptions of two new species

By

Mehrotra, Rahul
Caballer Gutiérrez, Manuel
M. Scott, Chad
Arnold, Spencer
Monchanin, Coline
Chavanich, Suchana

Type

Article

Date of Publication

2020

Original Publication

ZooKeys

Volume

969

Pages

85--121

Subjects

biodiversity exploration , cryptic species , Elysia , Heterobranchia , Plakobranchus

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.969.52941

 

Abstract

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.