Introduction to nudibranch ID

Literature and the web holds a vast store of information about nudibranchs. In most case the key to accessing this wealth of information is through the name. However, without the name, finding anything is tricky. Gary Cobb and Richard Willan of "Undersea Jewels" and www.nudibranch.com made a great leap forward by presenting nudibranch in colour groups.

Here you can browse for nudibranch by name or by colour and the concept of colour density is introduced to make identification easier.
Within a colour group individuals are roughly arranged horizontally by texture and vertically by colour density.
"smooth" animals - something like a typical Glossodoris- appears on the right, "lumpy" animals like Phyllidia or Hoplodoris appear towards the middle, and "hairy" animals like Flabellina appear on the right.
Animals with a high percentage of a given colour appear at the top of the index, animals with a low percentage of the given colour appear at the bottom .

Individuals may be found in a number of colour groups, depending on how many conspicuous colours they have.

Obviously actual colour differs between individuals and apparent colour changes with the lighting conditions in the photo, the viewer's perception and even the calibration of the viewer's screen. I have attempted to take these factors into account by duplication.

The index is in the left panel and the individuals will appear in the right panel. Click on an item in the left panel to change the contents of the right.

I have not recorded much information about individual species. I am not an expert, Sea Slug Forum is where the knowledge lies and it is just a click away. Similarly, I have not attempted to show a lot of pictures of a particular species. For a huge collection of nudibranch photos showing diversity and distribution, click through to Nudipixel.


If you can't find what you're looking for among our nudibranch collection which includes other Opisthobranchs, checkout flatworms or shelled molluscs.