Phyllodesmium cf. magnum Rudman, 1991

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

Phyllodesmium cf. magnum Rudman, 1991 Figure 18I

Material examined.

One specimen 15 mm, TT; one specimen 35 mm, SB.

Ecology.

In soft sediment habitats outside coral reef habitats, found regularly on or in the immediate vicinity of Dendronephthya octocorals, though active feeding has not yet been confirmed. Depth 16-28 m.

Distribution.

Unknown

Remarks.

The present species externally appears to match Phyllodesmium magnum Rudman, 1991, though smaller with relatively short cerata and no brown pigment on the animal, having pale yellow tips to rhinophores and oral tentacles. All individuals recorded to date were separately found on or very close to Dendronephthya spp., distant from any colonies of Sinularia which at Koh Tao grow only on rocks in shallower coral reef habitats. While it is possible that some animals recorded at Koh Tao are indeed P. magnum with differences in external colouration reflecting a drastically different diet from that known for P. magnum , the present species is provisionally treated as distinct due to its unique ecology.

Figures

Figure 18. A Myja cf. longicornis 9 mm (photograph by Phannee Mccarthy) B, C Noumeaella sp. 1 5 mm D, E Noumeaella sp. 2 5 mm (photographs by Tony Myshlyaev) F Phidiana militaris 35 mm (photograph by Pau Urgell Plaza) G Phidiana sp. 7 mm H Phyllodesmium magnum 30 mm I Phyllodesmium cf. magnum 35 mm (photograph by Pau Urgell Plaza) J Phyllodesmium opalescens 35 mm, (photograph by Guillaume Gandoin) K Phyllodesmium sp. 55 mm (photograph by Pau Urgell Plaza) L Armina occulta 65 mm.