: Phyllodoce mucosa.

This is a common bristle worm in Norway inhabiting shallow water sediments. Phyllodoce mucosa is easily recognised by the characteristic colour pattern when alive. Animals are whitish with a large yellow spot behind the eyes, and also a large brown spot flanked by two yellow spots on each segment. 

Phyllodoce mucosa Ørsted, 1843
Creative Commons Attribution | Arne Nygren | Institutionen för marina vetenskaper, Göteborgs Universitet
Kart. Utbredelse i Norge.