nudibranch

This uncharacterized species of nudibranch, genus Cyerce, can be distinguished by the delicate red lines running along the edges of its soft, jelly-like structures. 

An international panel of scientists selects the 10 most interesting organisms discovered last year.

A species of sea slug discards its penis after mating, then grows another the next day, a tactic that may have evolved to avoid passing on the sperm of competitors.