Re: Tylodina fungina

Dear Kevin,
There's no extra charge for the taxonomic lesson - using 'nudibranch' as a general name is a common mistake in usage which just becomes confusing. Accuracy is important, not for its own sake, but because scientific names are more than a simple 'label' to attach to a species, they are a guide to the evolutionary history and relationships of the species. A bit like family names [surnames] in some human societies. For example all true nudibranchs are carnivores, so if we find a nudibranch-looking animal, such as Stiliger aureomarginatus, feeding on algae, then we can be pretty sure it is not a nudibranch and is most probably a sacoglossan. Scientific names give us clues to the biology and natural history. For example all species of Tylodina feed on sponges in the Order Verongida, Family Aplysinellidae, so if you find a species of Tylodina, even a new one, you can make a fairly confident prediction that it will feed on an Aplysinellid sponge.

Concerning the eyes, I suspect its a question of magnification. In larger animals, the eyes will be proportionally smaller in your photos so less easy to see. In Jim Lyle's message #14710  there is a close-up shot of the head of a 3 cm long animal and the eyes are quite visible, and certainly in the species I am more familiar with, Tylodina corticalis, the eyes are quite obvious even in a 5 cm long animal.

In your last message you mention a length of 3 inches, which is about 75 mm, much larger than the 30 mm length mentioned by Behrens & Hermosillo (2005). It's always possible you have found some very large animals so it would be nice to confirm the measurements if possible.

Best wishes,
Bill Rudman