Coryphellina cf. lotos Korshunova et al., 2017

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

Coryphellina cf. lotos Korshunova et al., 2017 Figure 20I, J

Material examined.

Two specimens 35-40 mm, HWP; two specimens 35 mm, KKR.

Ecology.

Often feeding on hydroids growing among rocks and corals in deeper coral reef habitats and on stable substrates such as discarded nets and the remains of large terrestrial plant matter in soft sediment habitats. It is likely that the currently unknown prey hydroid of this species is able to grow in greater abundance away from shallow coral reef habitats. Depth 10-35 m.

Distribution.

Coryphellina lotos is currently known only from Japan ( Korshunova et al. 2017a). A similar species is here recorded for the first time from Thai waters.

Remarks.

Specimens from Koh Tao strongly resemble Coryphellina lotos ; however, a few differences may indicate a possible cryptic species. While C. lotos is described as light violet with parts of the rhinophores, oral tentacles, and cerata apices as lilac to reddish lilac ( Korshunova et al. 2017a: fig. 38A-E), specimens from Koh Tao appear have a background colour ranging from almost colourless to pale blue-violet, with rhinophore apices and subterminal bands on oral tentacles and cerata being a much deeper purple than the reddish violet of C. lotos . Most distinctive, however, is the presence of a mid-dorsal deep purple line which remains continuous in some specimens, entirely broken or limited to the oral surface in others, and completely absent in yet other specimens. The same pattern seen (if present) in the dorsal line is often mimicked laterally on both sides of some specimens. While no mention of dorsal or lateral linear pigmentation was made in the description of the species, these lines are visible in images provided supplementing the description ( Korshunova et al. 2017a: fig. 38A-C). Erroneously identified as Flabellina rubrolineata by Mehrotra and Scott (2016), the true identity of which has recently been shown to be restricted to its type locality in the Red Sea ( Ekimova et al. 2020; Yonow 2020).

Figures

Figure 20. A Bornella stellifera 31 mm B Lomanotus vermiformis 25 mm C Scyllaea fulva 45 mm D Melibe viridis 97 mm E Melibe sp. 22 mm F Eubranchus ocellatus 22 mm G Eubranchus sp. 7 mm H Coryphellina exoptata 15 mm (photograph by Tine Kvamme) I, J Coryphellina cf. lotos variants 40 mm (I) and 35 mm (J) K Samla bicolor 12 mm L Phestilla fuscostriata 15 mm.