This very small nudibranch, is surely not a rare species in the Netherlands. It might well be one of the most common species and can be found all year round. The animal itself is rather inconspicuous, because of its colour, body shape and size, but the egg-mass can easily be recognized in its favourite food (fine hydroids like Obelia and Laomedea). The egg-mass are small white and globular. Tergipes tergipes can often be found together with Eubranchus exiguus, but this last species has lozenge-shaped egg-masses. T. tergipes has only very few cerata, but the are rather large in relation to its total size.

The maximum length recorded in the literature is 8 mm, but our own observation show a much smaller maximum size (up to 4 mm).

Body and cerata are translucent. The tips of the cerata are white.

Its food can only be found in the shallow sub littoral, and with this also this nudibranch.

Atlantic icluding Mediterranean.