molluscivore

A molluscivore is a carnivorous animal that specialises in feeding on molluscs such as gastropods, bivalves, brachiopods and cephalopods. Known molluscivores include numerous predatory (and often cannibalistic) molluscs, (e.g. octopuses, murexes, decollate snails and oyster drills), arthropods such as crabs and firefly larvae, and vertebrates such as fish, birds and mammals. Molluscivory is performed in a variety of ways with some animals highly adapted to this method of feeding. A similar behaviour, durophagy, describes the feeding of animals that consume hard-shelled or exoskeleton bearing organisms, such as corals, shelled molluscs, or crabs.

==Description== Molluscivory can be performed in several ways: In some cases, the mollusc prey are simply swallowed entire, including the shell, whereupon the prey is killed through suffocation and/or exposure to digestive enzymes. Only cannibalistic sea slugs, snail-eating cone shells of the taxon Coninae, and some sea anemones use this method. One method, used especially by vertebrate molluscivores, is to break the shell, either by exerting force on the shell until it breaks, often by biting the shell, like with oyster crackers, mosasaurs, and placodonts, or hammering at the shell, e.g. oystercatchers and crabs, or by simply dashing the mollusc on a rock (e.g. song thrushes, gulls, and sea otters). It is hypothesized that human archaic ancestors such as early-Pleistocene Homo erectus on Java were predominantly molluscivorous: stone tool use, pachyosteosclerotic skeleton (slow+shallow diving), much larger brains (seafoods + DHA), fossilisations amid edible mussels (Pseudodon, Elongaria), island colonisations (e.g. Flores), early-Pleistocene intercontinental dispersal along coasts and rivers, enamel damage caused by "oral processing of marine mollusks" (Towle cs 2022 AJPA), ear exostoses (chronic cold-water irrigation), shell engravings (google "Joordens Munro"), etc., google "gondwanatalks verhaegen". thumb|right|250px|A common glowworm larva hunting snails Another method is to remove the shell from the prey. Molluscs are attached to their shell by strong muscular ligaments, making the shell's removal difficult. Molluscivorous birds, such as oystercatchers and the Everglades snail kite, insert their elongate beak into the shell to sever these attachment ligaments, facilitating removal of the prey. The carnivorous terrestrial pulmonate snail known as the "decollate snail" ("decollate" being a synonym for "decapitate") uses a similar method: it reaches into the opening of the prey's shell and bites through the muscles in the prey's neck, whereupon it immediately begins devouring the fleshy parts of its victim. The walrus sucks meat out of bivalve molluscs by sealing its powerful lips to the organism and withdrawing its piston-like tongue rapidly into its mouth, creating a vacuum. Another method, used by octopuses, nautilii and most molluscivoruous sea snails, is to use their radula to drill a hole through the shell, then inject venom and digestive enzymes through the hole, after which the digested prey can be sucked out through the hole. The larvae of glowworms and fireflies are simply small enough to enter the shells of terrestrial snails and begin eating immediately.