Bursatella cf. ocelligera (Bergh, 1902)

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

* Bursatella cf. ocelligera (Bergh, 1902) Figure 8G

Material examined.

One specimen 65 mm, SB.

Ecology.

In soft sediment habitats where it grazes on cyanobacterial mats on the benthos. Depth 18-25 m.

Distribution.

Bursatella ocelligera is known only from the Philippines ( Bazzicalupo et al. 2020) and the Gulf of Thailand ( Bergh 1902). Bursatella leachii is circumtropical ( Bazzicalupo et al. 2020) including Brazil ( Galvão Filho et al. 2015), Guadeloupe ( Ortea Rato et al. 2012), Spain ( González-Wangüemert et al. 2014), Italy ( Travaglini and Crocetta 2019), Tunisia ( Zakhama-Sraieb 2009), Morocco ( Selfati et al. 2017), Ghana ( Bebbington 1969), Iran ( Rezai et al. 2016), India ( Sethi et al. 2015), Vietnam ( Martynov and Korshunova 2012), Australia ( Nimbs and Smith 2016), New Zealand ( Appleton et al. 2002), South Africa, Madagascar, and Hawaii ( Gosliner et al. 2008).

Remarks.

Eales and Engel (1935) synonymised all species of Bursatella into the single circumtropical species B. leachii . Recent evidence ( Bazzicalupo et al. 2020) has supported the presence of a second species, B. ocelligera , based on internal morphological differences such as an unarmed penis and supported by molecular data. This name was attributed to specimens described from the Gulf of Thailand by Bergh (1902), who was the first to describe specimens with an unarmed penis. At present, there is no reliable way of discerning between the two species based on external morphology alone, and no available molecular data for specimens from the Gulf of Thailand. The internal anatomy of specimens from Koh Tao could not be investigated as part of the present study; however, the proximity to the type locality (Koh Chang) supports the need for comprehensive analyses of specimens from the Gulf of Thailand in particular, given the wide geographical range of B. leachii and the recent separation of other ‘circumtropical’ aplysiids.

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).