wear your heart on your sleeve. to make your feelings and opinions obvious to other people John's always worn his heart on his sleeve, so there's no doubt who he'll be supporting. See also: heart, on, sleeve, wear. Related vocabulary: wear something on your sleeve.
In many bivalves and snails, and in cephalopods, part of the mantle is modified into a siphon, which can be used to pump water through the mantle cavity for respiration, feeding and/or jet propulsion. Freshwater and marine mollusks have gills (called ctenidia) for respiration, located in the mantle cavity. In most bivalves, these are enlarged and serve to trap food particles as well (Morton 1983).
Section 1 - Mollusks. Mollusks are invertebrates with soft, unsegmented bodies that are often protected by a hard outer shell. In addition to a soft body often covered by a shell, a mollusk has a thin layer of tissue called a mantle that covers its internal organs, and an organ called a foot.Mollusks have bilateral symmetry and a digestive system with two openings.Most species of mollusks have an open circulatory system, in which the blood is not always inside blood vessels. Most mollusks that live in water have gills, organs that allow oxygen from the water to enter the body.lams, oysters, scallops, and mussels are bivalves. Bivalves are mollusks that have two shells held together by hinges and strong muscles. Bivalves live in all kinds of watery environments. Bivalves do not have radulas.