Stylocheilus longicauda (Quoy & Gaimard, 1825)

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

Stylocheilus longicauda (Quoy & Gaimard, 1825) Figure 8H

Material examined.

One specimen 45 mm, SRB; one specimen 30 mm, TT.

Ecology.

In soft sediment habitats rarely and upon mooring ropes where it grazes on cyanobacteria. Far less common than S. striatus. The association with mooring ropes is believed to be driven by its pelagic lifestyle, as these ropes act as mid-water substrates for cyanobacterial growth. Depth 5-18 m.

Distribution.

Circumtropical including Brazil ( Galvão Filho et al. 2015), Gulf of Oman ( Fatemi and Attaran 2015), Red Sea ( Yonow 2008), India ( Chinnadurai et al. 2014), Australia ( Nimbs and Smith 2016), Tanzania, the Philippines, and Hawaii ( Gosliner et al. 2008). Documented from the Gulf of Thailand ( Mehrotra and Scott 2016).

Remarks.

Recent work ( Yonow 2012; Bazzicalupo et al. 2020), has indicated the need for morphological and molecular examination of S. longicauda across their range with the taxonomic validity of the species being questioned. In the present work, S. longicauda is treated as distinct from S. striatus based on differences in external morphology (consistently shorter papillae and yellow/lime-green colouration in S. longicauda ) and ecology. We here retain the use of the compound noun used in the original description of the species (see Nimbs et al. 2017).

Figures

Figure 8. A Migaya sp. 3 mm B Siphopteron makisig 3 mm C Siphopteron sp. 3 mm (photograph by Will Malsukum) D Philine orca 3 mm E Aplysia kurodai 30 mm (photograph by Geoffrey Chamayou) F Aplysia nigrocincta 9 mm G Bursatella cf. ocelligera 65 mm (photograph by Elouise Haskin) H Stylocheilus longicauda 45 mm (photograph by Kirsty Magson) I Stylocheilus striatus 29 mm J Berthella cf. caledonica 10 mm K Berthella martensi 60 mm (photograph by Paddy Steele) L Pleurobranchus forskalii 130 mm (photograph by Tine Kvamme).