Pectenodoris trilineata from Lembeh

Dear Franco,

If you look through earlier messages on this species you will see that Pectenodoris trilineata shows quite a lot of variation in the presence of yellow on the white lines. Sometimes there are really only two lines.

Your upper photo illustrates quite well how difficult it can be to find out what these animals are feeding on. The animal you describe as being buried in the sand is almost certainly burrowing and feeding on its  favourite food - a greyish-blue species of Dysidea. I suspect all the background in that photo, which looks like sand, is a layer of Dysidea over which are scattered grains of sand and shell grit. In a close-up, I have ringed a small part of the sponge colony which is raised above the rest. In this bit you can see the sponge structure fairly clearly. Have a look at the sponges on the Fact Sheet for comparision.

Best wishes,
Bill Rudman