Elysia obtusa Baba, 1938

Mehrotra, Rahul, A. Caballer Gutierrez, Manuel, M. Scott, Chad, Arnold, Spencer, Monchanin, Coline, Viyakarn, Voranop & Chavanich, Suchana, 2021, An updated inventory of sea slugs from Koh Tao, Thailand, with notes on their ecology and a dramatic biodiversity increase for Thai waters, ZooKeys 1042, pp. 73-188 : 73

* Elysia obtusa Baba, 1938 Figure 4L

Material examined.

One specimen 9 mm, CB; one specimen 12 mm, TW.

Ecology.

Among rubble, particularly found underneath the skeletons of dead Fungiidae corals, in shallow coral reef habitats. No association with prey was observed but is known to be part of a group of species feeding on the alga Bryopsis ( Krug et al. 2016). Depth 3-8 m.

Distribution.

Across the Indo-Pacific including India ( Apte et al. 2010), Taiwan ( Huang et al. 2016), Hong Kong ( Jensen 2003), Japan ( Trowbridge et al. 2011), Australia ( Nimbs and Smith 2016), Samoa ( Wägele et al. 2010), Madagascar, Malaysia, Papua New Guinea, the Philippines, Korea, Guam, Marshall Islands, and Hawaii ( Gosliner et al. 2008 as Elysia flava Verrill, 1901). Here representing a first record for Thai waters.

Remarks.

Both individuals recorded were found adhering to the underside of dead fungiid skeletons. The species is locally rare and here included as a first record for the Gulf of Thailand and Thai waters in general.

Figures

Figure 4. A Costasiella cf. kuroshimae 6 mm B Costasiella usagi 6 mm C Limapontiidae sp. 3 mm D Plakobranchus noctisstellatus 21 mm (photograph by Pau Urgell Plaza) E Plakobranchus ocellatus 32 mm F Plakobranchus papua 27 mm G Plakobranchus papua 21 mm on Holothuria edulis H Elysia aowthai 12 mm I Elysia asbecki 15 mm J Elysia cf. marginata 70 mm K Elysia mercieri 12 mm L Elysia obtusa 9 mm.