Another Samoan haminoeid

May 25, 2000
From: Don Barclay

Hi Bill,

Here's another one for you and Clay. This little haminoeid was collected around 1500 local (low tide), 20 May 2000 under a coral slab on the hard reef flat in front of Afono village, north Tutuila Island, American Samoa. Water was about one meter deep, and there was none of the filamentous algae in this area that has been associated with the other Haminoea species that I've found here. However, I did find a small Marginella under the same slab, similar to the Marginella species that I usually find in the other Haminoea areas, but I believe it is a different species. The bottom of the slab was covered with sponge growth and other life, including several Philbertia species, two Pyrene species, a few triphorids and a single Cypraea isabella.

The shell measures 4.1 x 2.3mm, is more elongate than the Haminoea cf. ovalis I've found here, and even has some sculpture (visible in the photos). It appears to belong to Clay Carlson's "orange-spotted" group. Any ideas?

Thanks a lot,


Barclay, D., 2000 (May 25) Another Samoan haminoeid. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Don,
Your animal is in the same family as Haminoea but I think it is a species of Atys or one of the other similar genera. It looks quite like Atys cylindrica but I think it is a distinct species. It looks quite like Limulatys ooformis Habe, 1952. Hopefully Clay Carlson can give us some advice.

Your photo (lower right) showing the underside (ventral side) of the animal shows how the foot in most haminoeids is very short, rarely extending back under the shell. I have marked the posterior end of the foot with an arrow. In haminoeids a flap of mantle tissue extends out of the mantle to form a secondary foot. It is only slightly enlarged in this species, but in many species, it is much larger and from above, animals such as Haminoea seem to have a large foot extending from the head to beyond the posterior end of the foot.
Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (May 25). Comment on Another Samoan haminoeid by Don Barclay. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Atys semistriata

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