Thorunna purpuropedis
Rudman & Johnson, 1985

Order: NUDIBRANCHIA
Suborder: DORIDINA
Family: Chromodorididae

DISTRIBUTION

At present known only from the Enewetak Atoll, Marshall Islands.

PHOTO

Enewetak Atoll, Marshall Islands, 10mm long alive, August, 1981. PHOTO: Scott Johnson

The body is elongate with a relatively narrow mantle margin. The anterior edge of the mantle is held horizontally while the sides fold down giving the animal a spatulate appearance. The mantle is purplish white with a broad orange band abound the edge, the inner half of the band appearing more opaque. On the inside edge of the orange border is an irregular line of red, usually thin but widening in places to give the appearance of a row of red spots.

The rhinophore stalks are transparent and the club has a whitish core, the lamellae being red. The seven gills are simply pinnate, coloured watery red, more opaque at the edges. They wave rhythmically and are arranged in a circle around the anus. The foot is pale purple, deepening posteriorly and on the oral tentacles. The posterior end of the foot extends beyond the end of the mantle when the animal is crawling.

Reference:
• Rudman, W.B. (1985) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris aureomarginata, C. verrieri and C. fidelis colour groups. Zoological Journal of the Linnean Society 83: 241-299.

Authorship details
Rudman, W.B., 1998 (November 11) Thorunna purpuropedis Rudman & Johnson, 1985. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/thorpurp

Related messages


Thorunna purpuropedis from Okinawa, Japan

February 19, 2004
From: Kunihiro Takahashi

Dear Dr.Rudman
I found this slug and two similar ones [message #12158, message #12247] at Okinawa.
Are they Hypselodoris bullocki?

Data
Date: 26 May, 2001
Location: Cape Maeda,Okinawa Japan
Depth: 10m
Length: 8~10mm
W/Temp: 25C degree
Photo by Kunihiro Takahashi

Best Regards,
Kunihiro Takahashi

manta9216@tontonme.ne.jp

Takahashi, K., 2004 (Feb 19) Thorunna purpuropedis from Okinawa, Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12248

Dear Kunihiro,
I am pretty sure this is Thorunna purpuropedis. As I said in answer to your first message, there are quite a few species with very similar colour patterns. It is often necessary to dissect them and look at their anatomy and radular teeth before we can be truly sure we have correctly identified them.
Best wishes
Bill Rudman

Rudman, W.B., 2004 (Feb 19). Comment on Thorunna purpuropedis from Okinawa, Japan by Kunihiro Takahashi. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12248

Thorunna purpuropedis? from Okinawa

August 5, 2000
From: Bob Bolland

Hi Bill,
To continue with an earlier thread concerning Thorunna purpuropedis, here's an image from Yukinobu Adachi's Homepage here on Okinawa [http://www.cosmos.ne.jp/~breach](submitted with his permission). This beautiful animal is similar to the one submitted earlier by Atsushi Ono; this one also has a break in the orange border near the rhinophores much the same as in T. montrouzieri. Perhaps this is a constant feature of the species in Okinawan waters, or perhaps a new species? In either case, this is a beautiful animal.

Data:
Maeda Point, Okinawa
Depth:34m
Length:6mm

Just thought I'd add the image to the Forum to illustrate some additional variation.
Cheers,
Bob

bollandr@rapid-link.ne.jp

Bolland, R.F., 2000 (Aug 5) Thorunna purpuropedis? from Okinawa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2817

Dear Bob,
Thanks to you and Yukinobu Adachi for the photo. Variations, puzzles, problems are always welcome.
Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Aug 5). Comment on Thorunna purpuropedis? from Okinawa by Bob Bolland. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2817

Thorunna purpuropedis from Kerama Id

June 15, 2000
From: Atsushi Ono

Dear Bill,
Thank you for your reply.

I think this Thorunna species is similar to T. montrouzieri. This maybe is the same as Bolland's animal Thorunna sp.#1.

I found this at 4m depth on dead coral at Kerama Is. near Okinawa. It was 7mm long, I found only one individual.

Could you help me to identify this?

Sincerely,
Atsushi Ono

ononini@cosmos.ne.jp

Ono, A., 2000 (Jun 15) Thorunna purpuropedis from Kerama Id. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2578

Dear Atsushi,
Thanks for sending this photo. It has helped me realise that I was wrong with the animal you sent on June 9.

Both the photo you have sent today, and the one on June 9 are Thorunna purpuropedis not Thorunna speciosus.

Bob Bolland's animal is Thorunna montrouzieri.

Thorunna speciosus does not have any red in its colour pattern and of the other two species with red, in Thorunna montrouzieri the orange border is absent posteriorly, while in Thorunna purpuropedis the orange band continues around the mantle edge.

One feature that is a bit puzzling is the orange border on either side just in front of the rhinophores. In other specimens of T. purpuropedis this continues around the front of the mantle, but in you photo there is a break as in specimens of T. montrouzieri. We will need more specimens and photos to clarify these species.

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Jun 15). Comment on Thorunna purpuropedis from Kerama Id by Atsushi Ono. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2578

Thorunna speciosus from Japan

June 9, 2000
From: Atsushi Ono

Dear Bill,

Here is a photo of an animal I think is Thorunna speciosus to compare with the two I think may be colour variations I sent in a separate message.

It is 13mm long and I found them at 5m depth on a coral reef at Kerama Is. near Okinawa in Japan.

Sincerely,
Atsushi Ono

ononini@cosmos.ne.jp

Ono, A., 2000 (Jun 9) Thorunna speciosus from Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2467

Dear Atsushi,
This is definitely T. speciosus but I don't think the other two photos you sent are colour variations of this species. Even if the orange border could vary to white, in T. speciosus there is always a break in the band on each side at the front of the mantle alongside the rhinophores. In the other animal, which I have tentatively called Thorunna cf. speciosus, there is no break in the white band bordering the mantle.

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Jun 9). Comment on Thorunna speciosus from Japan by Atsushi Ono. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2467