Cyerce cf. kikutarobabai
Hamatani, 1976

Family: Caliphyllidae


Sokodo, Hachijo Island, Japan. 6M depth. Approx 1cm long. 15 April 2001. Found by Nishina Chikako. PHOTOS: Nishina Masayoshi


Cyerce kikutarobabai

Possibly a colour form of Cyerce kikutarobabai.
• See Nishina's message.
• See C. kikutarobabai on Bob Bolland's website.

• Hamatani, I. (1976) A new species of Cyerce Bergh, 1871, C. kikutarobabai from Yoron Island (Opisthobranchia: Sacoglossa). Publications of the Seto Marine Biological Laboratory, 23(3/5): 283-288, Pl. 1.

Authorship details
Rudman, W.B., 2001 (April 23) Cyerce cf. kikutarobabai Hamatani, 1976. [In] Sea Slug Forum. Australian Museum, Sydney. Available from

Related messages

Another photo of Cyerce cf. kikutarobabai

July 14, 2002
From: Nishina Masayoshi

Dear Dr.Rudman,
My friend Tomohiro Natani who dove with us sent me much better photos of Cyerce cf. kikutarobabai. This is same specimen that I sent to you before. One thing that I noticed from this photo is the color of posterior foot. It's purple! So I suspect that body color of the animal is may be purple.

Data: 15 April 2001 at Hachijo Island

Best Regards,
Nishina Masayoshi

Masayoshi, N., 2002 (Jul 14) Another photo of Cyerce cf. kikutarobabai. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Nishina,
This has been waiting a while to be posted, but better late than never.
Bill Rudman

C. kikutarobabai from Northern Marianas

April 28, 2001
From: Clay Carlson

Here is a sample of one of the two C. kikutarobabai that we found in the Northern Marianas a few years ago. I think Bob Bolland has also reported this animal from the Okinawa area.

Data: 8 mm; Northern Marianas, Maug, 6 m; 5 July 1972.


Carlson, C. , 2001 (Apr 28) C. kikutarobabai from Northern Marianas. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Clay,
This is obviously the same as Bob Bolland has found in Okinawa and Nishina has just reported from the Japanese mainland. As I said before I wish someone could find an intermediate between this black animal ['Cyerce cf. kikutarobabai'] and the purple animal which matches Hamatani's original description of C. kikutarobabai.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Apr 28). Comment on C. kikutarobabai from Northern Marianas by Clay Carlson . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Re: Cyerce cf. kikutarobabai

April 26, 2001
From: Nishina Masayoshi

Good Morning Dr.Rudman
Thanks for your reply about my Cyerce. I always admire your broad knowledge and amount of information.

I even didn't know of Cyerce kikutarobabai so I am very glad to hear of it. I searched Cyerce kikutarobabai in Dr.Bob Bolland's web site, and his Cyerce kikutarobabai and what I sent you look almost the same. Necessary to say, Dr. Bolland says that he found only 3 C. kikutarobabai in the last 20 years in Okinawa and Mr. Ono says he found only 2 times at Zamani Island so far. What Mr.Ono found is very similar to what you found in New Caledonia. So I doubt that there are 2 different types of color variation of C. kikutarobabai.

I don't know where Dr.Baba or Hamatani found it but may be this is the first record for mainland Japan, or at least the first record at Hachijo Island. I have included some more photos you may be interested in.

Masayoshi, N., 2001 (Apr 26) Re: Cyerce cf. kikutarobabai. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Nishina,
I thought I had looked on Bob Bolland's site before I answered your question but obviously I missed it. His photo from Okinawa certainly looks identical to your photo. But Hamatani's original description is of an animal like mine from New Caledonia and Atsushi Ono's from Kerama Ids. Hamatani's animal was collected at Yoron Is., Amami Islands, which I find in my Atlas are part of the Ryukyu Group, north of Okinawa. So I guess your record is probably the first from mainland Japan.

I suspect your animal is a particularly darkly pigmented or melanistic form of C. kikutarobabai, but it would be nice to get some more information and preferably an intermediate colour form. In one of the other photos you sent me, which I have posted with this message, you can see that the black pigment on the cerata does not go right to the bottom of the cerata. The same thing happens with the purple pigmentation in more 'typical' C. kikutarobabai.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Apr 26). Comment on Re: Cyerce cf. kikutarobabai by Nishina Masayoshi. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Is this Cyerce nigricans?

April 25, 2001
From: Nishina Masayoshi

Hello Dr.Rudman,
Is this Cyerce nigricans? What I have noticed is that the cerata are not flat, rather say looks like a balloon. The rhinophore color is brighter than the colour of the body. Size is about 1cm, so it is also considered some juvenile.

I believe that Cyerce nigricans has much colour variation, but I have never seen this color pattern and figure of the cerata. I'm sorry for the photograph which is not in focus.

The animal was found by Nishina Chikako, 15 April 2001, at Sokodo, Hachijo Island, Japan. It was at about 6M depth where it was moving on sand surrounded by the rocky reef.
Water Temp: 18-20C degree.

Sincerely yours
Nishina Masayoshi

Masayoshi, N., 2001 (Apr 25) Is this Cyerce nigricans?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Nishina,
Your animal has colour similarities to C. nigricans but as you say, the differences are quite considerable. I also agree that the inflated cerata are unlike those of C. nigricans. It would be interesting to know more about the juvenile colour variation in Cyerce nigricans and Cyerce nigra.

I suspect your animal may be a colour variation of C. kikutarobabai Hamatani 1976 which I have just added to the Forum because of your message. You will see from the photos on the C. kikutarobabai Page that there are some important similarities. In both your animal and C. kikutarobabai the head, rhinophores and oral tentacles are purple and spotted with white. In both species, the cerata are inflated, have yellow spots on both sides, and have an orange or orange-yellow edge to the cerata. Your animal differs, however, in having a black, rather than purple, background colour on the cerata.

There are too few records of C. kikutarobabai for us to know how variable in colour it is, and whether your animal represents another new species or just a colour variant of C. kikutarobabai or even C. nigricans. Perhaps someone can give us some more information
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Apr 25). Comment on Is this Cyerce nigricans? by Nishina Masayoshi. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from