Could It Be.....
What am I talking about? Well....I am talking about this nudibranch that was sighted by Ivan Choong during last week dive at Pulau Hantu.
After checking The Sea Slug Forum and Neville Coleman's Nudibranch Encyclopedia book, this nudibranch looks similar to Okenia purpurata.
But the thing is that Okenia purpurata, according to The Sea Slug Forum, has 4 to 5 gills. Whereas, the ones found at Hantu as shown in the pics above have only 3 gills. Moreover, the Forum put that the distribution is known only from northern New South Wales, eastern Australia and the book stated that Okenia purpurata is Australia endemic.
Previous sightings of this nudibranch were recorded by The Hantu Bloggers during their dives too. One of them on 27th May 07 and the other on 21st Oct 06.
So Ivan sent his pics to three nudibranch experts (Dr Richard Willan, David W. Behrens and Neville Coleman) for the ID of this nudibranch.
They all agreed that it looks similar to Okenia purpurata. With Dr Richard Willan temporarily naming it as Okenia cf purpurata.
This means that it could be Okenia purpurata or something closely related or looks quite like it. This also mean that its ID will remain a mystery until further study can be done about its internal anatomy.