Re: On Elysia japonica, E. abei & E. amakusana

September 14, 2002
From: Kathe R. Jensen

Dear Bill, Nishina, Jun and others,

I just returned from a field trip to Cambodia (where we released the first Cambodian sea turtle with a Japanese satellite transmitter) to find this series of photos and discussions about the identity of Elysia abei and E. amakusana. I am very happy to notice that our Japanese colleagues have reached the conclusion that they are colour forms of the same species. Now we need to decide whether this one species also includes Elysia cf. japonica from Hong Kong - and possibly also Japan. And maybe we need to convince Bill that this species is most likely Eliot's species (of course we can never be sure). Unfortunately none of these excellent pictures show the arrangement of the pericardium and dorsal vessels. This was my major reason for synonymizing the Hong Kong animals with E. japonica. The pericardium is short and with a characteristic constriction. The posteriormost pair of dorsal vessels run parallel to the foot, and the area between these vessels is more transparent in colour (probably due to absence of digestive tubules and/or reproductive ductules). I think that this will be more easy to see in preserved animals - or at least animals kept in small dishes, so the parapodia can be manipulated apart.

The tooth denticulation (absent according to Eliot, present in Baba's species and in the Hong Kong animals) is not a good character when comparing an old description to newly collected ones. Even Eliot, when redescribing E. grandifolia, noticed that the fine serrulations were only visible under the highest power.

Eliot had 18 preserved specimens of this species, and apart from E. trisinuata (which is obviously not this one), I don't think any other Elysia in Japan is that common. So, if at all possible, I would like to ask our Japanese colleagues to try and look at the pericardium and pattern of dorsal vessels.

All the best,
Kathe

jensen@ait.ac.th

Jensen, K.R., 2002 (Sep 14) Re: On Elysia japonica, E. abei & E. amakusana. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7957

Thanks Kathe,
Bill Rudman

Factsheet

Elysia abei

Related messages

  1. On Elysia japonica, E. abei & E. amakusana
    From: Skip Pierce, September 13, 2002
  2. Elysia abei and E. amakusana
    From: Yoshiaki J. Hirano, September 13, 2002
  3. Colour forms of E. abei (1)
    From: Nishina Masayoshi, September 9, 2002
  4. On Elysia japonica, E. abei & E. amakusana
    From: Nishina Masayoshi, September 9, 2002
  5. Colour forms of Elysia abei (2)
    From: Nishina Masayoshi, September 9, 2002
  6. Colour forms of Elysia abei (3)
    From: Nishina Masayoshi, September 9, 2002
  7. Colour forms of Elysia abei (4)
    From: Nishina Masayoshi, September 9, 2002
  8. Re: Elysia abei from the Japan Sea
    From: Cynthia Trowbridge, September 23, 1999
  9. Elysia abei from the Japan Sea
    From: Shigeru Hayashi, September 22, 1999

Show factsheet and all related messages