Roboastra tigris? from Galapagos

Dear Patty,
This is an interesting find. From the long tubular oral tentacles [see dark blue structure in lower right photo] this is a species of Roboastra which are voracious carnivores, well-known for feeding on relatives, such as species of Tambja. The only species I know of from the eastern Pacific is Robosastra tigris which has an ochre background colour and a few longitudinal blue bands outlined with thin pale yellowish lines. It is possible that your animal is a colour form with extra blue bands, but I think we would need to see some animals with an intermediate colour pattern for me to feel comfortable with that suggestion. However considering how little we know of these animals and their distribution in the eastern Pacific, the suggestion is definitely not out of the question. It wiuld be interesting to see if you could observe this animal feeding on other nudibranchs, in particular the Tambja in your other message.

I am certainly interested in seeing photos of any sea slugs you find in the Galapagos Ids. The marine fauna of the East Pacific is not well known so any records from the region, even of apparently common animals is valuable information.

Best wishes
Bill Rudman