Don Barclay has sent a list of opisthobranchs he found in Tonga early in 2001. I asked him to send photos of those he was able to photograph because there are few records in the literature from Tonga. From our knowledge of shelled molluscs, biodiversity (the number of species present) drops as we move east across the Pacific, so knowing what species occur in Tonga, towards the eastern limits of the Indo-West Pacific faunal region, is of interest.

To get a complete list of species recorded in the Forum specifically from Tonga, use the SEARCH button and enter tonga in the search box. In that way you will get species, if any, added independently of Don Barclay's.

Authorship details
Rudman, W.B., 2001 (May 26) Tonga. [In] Sea Slug Forum. Australian Museum, Sydney. Available from

Related messages

Opisthobranch records from Tonga

May 29, 2001
From: Don Barclay

Dear Bill,
Here is a list of the sluggish opisthobranchs I found in Utungake Island, Vava'u, Tonga in February of 2001. I wasn't specifically hunting slugs in Tonga, but did attempt to take note of the ones I saw. It's not a very impressive list, but for the record, here are the species of Opisthobranchs I found there, all seen in the Utungake area. (Pyramidellids, etc. not included)

Per your request, here are the rest of the pics I took. I've been hesitant to dump these to the Forum and simply add to the backlog, but perhaps the geographic records will be of some value to someone. Juvenile Hexabranchus sanguineus was fairly common in shallow water in front of the Tongan Beach Resort, but I didn't see any adults. I intended to take photos of Chelidonura inornata, since I had never seen it in person before, but forgot about it and found it in one of my containers after I got back to Samoa. It was still identifiable, but wouldn't have made a very attractive photo. I've included a couple of poor photos of for your Chromodoris decora and Noumea norba. In fact, I'll go ahead and send the lone photo I took of Phyllidiopsis striata, too, lest it turn out to be something else : ).

Tongan Slug/Bubble List
February 2001 Utungake Island, Vava'u

Atys sp. 1
Hexabranchus sanguineus
Gymnodoris ceylonica
Halgerda carlsoni
Cadlinella ornatissima
Chromodoris decora
Chromodoris kuniei
Chromodoris preciosa
Glossodoris hikuerensis & food sponge
Noumea norba
Flabellina bicolor
Phyllidiopsis striata

Not photographed:
Pupa coccinata
Pupa nitidula
Pupa sulcata
Bullina lineata
Chelidonura inornata
Atys naucum
Atys semistriata
Bulla ampulla
Bulla vernicosa
Plakobranchus ocellatus
Elysia ornata
Dolabella auricularia
Dolabrifera dolabrifera
Chromodoris aspersa
Chromodoris fidelis
Phyllidia coelestis
Phyllidiella pustulosa


Barclay, D., 2001 (May 29) Opisthobranch records from Tonga . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Don,
These records are very interesting, for as I say at the top of the page, we know very little about Tonga's opisthobranch fauna, and being towards the eastern limit of the Western Pacific it is interesting to know what occurs there.
Bill Rudman

Rudman, W.B., 2001 (May 29). Comment on Opisthobranch records from Tonga by Don Barclay. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from