L. depressa feeds on coenocytic, filamentous algae, by holding a filament vertically in a groove at the front of its head while it punctures it and sucks out the cytoplasm, leaving a colourless tube (1).
Three spawn masses on the algae; bred in captivity. These ova each have a black spot at this stage of development. They are much smaller than L. senestra eggs, but more numerous; up to about 200 per spawn mass.

marinvert.senckenberg.science/image-browse/