Bornella sp. 2

Order: NUDIBRANCHIA
Suborder: DENDRONOTINA
Family: Bornellidae

PHOTO

Upper: Pulau Hantu, 13m, Singapore, South China Sea, 29 April 2007, On silty rubbles/substrate. Length: 35 mm. Photographer: Toh Chay Hoon. Lower:  Beting Bronok, 0m, Singapore, South China Sea, 05 July 2008, Submerged reef intertidal. Length: 100 mm. Photographer: Toh Chay Hoon.

I suspect this is another unnamed species which has escaped our notice. Perhaps it is a very extreme form of Bornella hermanni? There seem to be only three pairs of dorso-lateral processes while in B. stellifer we would expect five or six. However the dorso-lateral processes are shaped more as in B. hermanni with one major lobe or papilla, and a number of smaller ones. However the heavy white pigmentation and red reticulate pattern, even on the dorso-lateral processes are quite different. In this animal the major papilla in each lateral process, and the major papilla on the rhinophore sheaths is contoured with vertical wrinkles which seem present even when the processes are extended. The papillae also have a reddish reticulate pattern, in some cases the red extending into larger patches.

The rhinophore sheath is similar to B. hermanni in shape, but again, the red reticulate pattern is quite different. The translucent red of the rhinophores and in some animals the gills as well, is unusual, but it could just be a manifestation of a population with an excess of red pigmentation. I could call this Bornella cf. hermanni, but that might be confusing, so until we can examine specimens anatomically I have separated it as Bornella sp. 2.

Authorship details
Rudman, W.B., 2009 (February 12) Bornella sp. 2 [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/bornsp2

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