This publication, very different from the other, talks about nudibranch, a group of sea mollusks.
Nudibranch are mollusks in the Opisthobrach group. Opisthobranchs are animals with a partial or total detersion. That is, the anus and the gills are in the right or back part of the body. In addition, they have two pairs of tentacles, which are to detect chemical substances. One of them, which is called rhinophor, are very developed. In case of shell, it is very reduced. Opisthobranchs are marine and they live under the rocks and algas in shallow waters.
Nudibranchs are animals without shell in the adult stage and they have naked gills, with different morphologies and in different places in their body. They are noted for their often extraordinary colors, but there are some transparent nudibranchs that can emit light. They are carnivorous animals that eat other invertebrates and eggs from other nudibranchs. Nudibranchs are hermaphroditic but they cannot fertilize themselves. Nudibranchs that feed on hydrozoids can store their nematocysts (stinging cells) in their body.
Here, there are some pictures from nudribranchs in catalan coast. All of them are from Club d’Immersio Biologia:
[On the top, Flabellina affinis; in the middle, Hypselodoris bilineata (left) and Peltodoris atromaculata (right); on the bottom, Tritonia manicata (left) i Chromodoris luteorosea (right)]
If you want more information, you can look for:
– Grup de Recerca d’Opistobranquis de Catalunya (GROC): http://www.opistobranquis.org/ca/guia#5
– Club d’Immersió Biologia (CIB): http://www.cibsub.com/biofamilia-moluscs_opistobranquis-27757