Feeding
Bonellia viridis are deposit feeders and specifically detritivores. They use the dorsal side of their proboscis to move across sediments and graze on benthic substrates. Then they use the ventral side to bring particles back to their mouth. They are selected with care, particles over 300µm are rarely picked up, medium sized particles between 100 and 300µm are picked up using a combination of muscular and ciliary actions, and small size particles <100µm are picked up by ciliary action ([1] Jaccarini et al. 1977).
These particles stick to the proboscis because of the secreted mucus and are then transported toward the mouth through ciliary action.
From time to time, unwanted particles are picked up, and depending on the size, they are rejected at different sites of the proboscis. Large unwanted particles are rejected in the neck area while medium ones are rejected at the stem gutter and small ones just before the mouth ([1]Jaccarini et al. 1977).
.JPG)
Drawing by Lucie Malard, adapted from [1] Jaccarini et al. 1977.
Proboscis general structure
Blue arrows indicate the ciliary movements
Red arrows indicate the possible rejection paths |