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.
It is always nice to look at someone’s work, especially when it is done with endless enthusiasm. Our shrimp lives in burrows with Cryptocentrus gobies (Y-bar Shrimp Goby, Cryptocentrus fasciatus in our case). The shrimp digs and maintains the burrows. With a soft sand bottom, it is easier to dig a home than to maintain it. Watch this video and you will understand why!
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.