• Norwegian: smørsnegl


The color is usually yellow, but brown, pink green and white variants exist too. The mantle is covered in blunt tubercles. This is one of the bigger sea slugs in Norway, as it can reach a body length of 12 cm. There are seven or eight anterior gills. It may be confused with the similar Geitodoris planata, which are more flattened and have light star-like blotches on the mantle.


It feeds on sponges. It seems thrives on a variety of substrates. It is registered on depths from the subtidal zone to 300 meters.


It is registered along the coasts of Europe, from Norway to Spain and in the Mediterranean.