Flatworms; Platyhelminthes

Visitors to Koh Phangan, snorkelling or diving for the first time will often confuse Flatworms with Nudibranchs. Flatworms are more primitive animals and have no rhinophores or external gills (although, of course, it’s never quite that simple…)

A commonly encountered flatworm, comfortable when swimming as well as moving over the bottom.

They seem to have a distinctive ridge on the back and a special shape of head.

We're not sure of the determining characteristics of these beasties - they look wider than our Pseudoceros flatworms. (2 Galleries)

They seem to be a little slimmer than their Pseudobiceros relations. (4 Galleries)

Looks like a Nudibranch at first, with its rhinophore-like head tentacles.

Up to 4 cm in length, with yellow spots on black, and white edges.

Some tentatively named, others not, because they are not easy to classify even if they are listed...