The family Harpidae comprises elegant marine gastropods with shell, resembling the strings of a harp. They are nocturnal hunters, hiding in the sand during the day and feeding on crabs and shrimps at night. The prey is enveloped by the foot and mucus, then saliva containing digestive enzymes is injected. Finally, partly digested crab is sucked out by the mollusc.
Pseudoceros imitatus (Mimic Flatworm), one of my favourite flatworms, mimic Phyllidiella pustulosa (Pimpled Phyllidiella), very common toxic nudibranch. Phyllidiella can emit very toxic substances on the skin, extracting them from the sponges it feeds on. Our flatworm unfairly enjoys poisonous fame, avoided by predators!
Can you tell flatworm from nudibranch on this photo?
Juveniles are often funny, like this small Blue-Eyed Hermit Crab, Dardanus scutellatus. You can easily recognise this crab by blue or grey eyes with white eyestalks and 1st antenna with back stripe.