coup de grÃ¢ce in British English. See all translations. coup de grÃ¢cenoun [ S ] uk â /ËkuË dÉ ËÉ¡rÉËs/ us â /ËkuË dÉ ËÉ¡rÉËs/ formal. âº an action that ends something that has been gradually getting worse, or that kills a person or animal in order to end their suffering: Jane's affair was the coup de grÃ¢ce to her disintegrating marriage. Thesaurus: synonyms and related words.
Bivalves is a class of marine and freshwater molluscs with about 30,000 species including scallops, clams, oysters, razor shells, shipworms and mussels. Most bivalves are marine usually found in shallower water but some live in brackish and freshwater.
The bivalves (meaning two-shells) are perhaps the most well known mollusks simply because of their history as a source of food. Clams, mussels, oysters and scallops are all bivalves. There are about 15,000 known species of bivalve, with about 80% of them being marine (the rest are found in fresh water).ollusks usually have a shell (although some do not). Mollusks also have an extension of the body wall called the mantle. This portion of the animal's anatomy is responsible for secreting the shell. The mantle encloses the mantle cavity which contains the Ctenidia (gills), anus and excretory pores.