Nudibranch 101

First, let's start with the gills. Warning: Right now I'm a bit lazy to refer to the book, so I'm making things up as I go along. The gills .... um... I guess they allow them to breathe. There we go!

The horn-like thingies are called rhinophores (not ears).

Nudibranchs do the strangest things... like hang upside down

.... or straddle uncomfortable stones

... or freefall

Above: Emm's Hypselodoris

The Choo-Choo Train (aka trailing behaviour)

Mating Nudibranchs