Click the thumbnail photos to enhance!
"I can't put a name on it right off. It has some similarities to Elysia japonica - the dark tips of tail and rhinophores, but it is a lot paler than any I have seen before. I have seen some very pale ones, but usually the inside of the parapodia would show the contents of the digestive gland tubules through the skin. This is usually difficult to see in the field becase they keep the parapodia closed. Elysia japonica also has a characteristic constriction of the pericardium, which I cannot see on your pics."
I call it Elysia cf. japonica - cf. is an abbreviation from a Latin word (confer) and means 'refer to' or 'compare with', here it means it could possibly be Elysia japonica or perhaps something closely related, or at least similar in appearance.
There are many pictures of Elysia japonica as Elysia amakusana from Japan online,
Kathe Rose Jensen suggested in hjer 1985 Hong Kong paper that both E. amakusana and E. abei are probably synonyms of E. japonica.
Bill Rudman writes: "I feel it would be better to discard Eliot's name as unidentifiable and use a later name if there is one."
WoRMS lists all of them (E. amakusana, E. abei, and E. japonica) with status accepted.
Jensen,KR (1985): Annotated checklist of Hong Kong Ascoglossa (Mollusca: Opisthobranchia), with descriptions of four new species.
In: Proceedings of the 2nd International Workshop on the Malacofauna of Hong Kong and Southern China, Hong Kong, 1983.
(Eds: Morton,B; Dudgeon,D) Hong Kong University Press, Hong Kong, 77-107.
MolluscaBase eds. (2021). Elysia Risso, 1818. Accessed through:
World Register of Marine Species
at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=137928 on 2021-05-06
More information on Elysia cf. japonica are on Bill Rudman's Sea-Slug Forum!
How to cite:
Köhler, E. (2021), published 6 May 2021, Elysia cf. japonica Eliot, 1913
available from https://www.Philippine-Sea-Slugs.com/Sacoglossa/Elysia_japonica_cf.htm