Marine nudibrach Tergipes?

Marine nudibrach Tergipes?

Observation - Marine nudibrach Tergipes? - UK and Ireland. Description: One of several similar found in low shore hydroids seen under microscope, usually near Dynamena p and associated with egg clusters. Can anyone tell me why hydroids & nudibranchs so common on N Devon shores but not found (by me) in N Cornwall (Polzeath

One of several similar found in low shore hydroids seen under microscope, usually near Dynamena p and associated with egg clusters.

Can anyone tell me why hydroids & nudibranchs so common on N Devon shores but not found (by me) in N Cornwall (Polzeath, equally exposed)?