Trinchesia sp. 3

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

* Trinchesia sp. 3 Figure 21K

Material examined.

Three specimens 12-45 mm, SN.

Ecology.

Cryptic on its host hydroid Macrorhynchia sp., colonies of which are found exclusively in soft sediment habitats outside the coral reef. Depth 12-24 m.

Distribution.

' Cuthona yamasui ' ( Gosliner et al. 2008) is known from Tanzania, Oman, Malaysia, the Philippines, Indonesia, Japan, and Australia. Here representing a first record for Thai waters.

Remarks.

Very similar to Trinchesia sp. 2, with which it shares a prey species (alongside Lomanotus vermiformis ). Distinguished by the presence of a white body with brown rhinophores and oral tentacles, unlike the brown body with white markings around the rhinophores as seen in Trinchesia sp. 2. Cerata in the present species are basally transparent (with the blue digestive glands clearly visible) turning blue with a thin black band, a thick yellow band, and another thin black subapical band below translucent apices. The cerata of Trinchesia sp. 2 on the other hand are basally opaque white followed by a distinct large blue band and yellow apices with colourless tips. The present species is similar to Tenellia sp. 15 and Tenellia sp. 16 of Gosliner et al. (2018). See above comments regarding genus and family instability.

Figures

Figure 21. A Phestilla lugubris 30 mm B Phestilla melanobrachia 30 mm (photograph by Tom Jang) C Phestilla cf. minor 18 mm D Phestilla viei 20 mm E Phestilla subodiosa 2 mm F Phestilla sp. 1 8 mm G Phestilla sp. 2 4 mm H Phestilla sp. 3 3 mm I Trinchesia sp. 1 10 mm (photograph by Wanraya Kraikruan) J Trinchesia sp. 2 40 mm K Trinchesia sp. 3 45 mm (photograph by Pau Urgell Plaza) L Trinchesiidae sp. 6 mm.