Glossary

Mussel survey Adductor muscle: Large muscle that bivalve mollusks possess which are attached to both valves of the shell and when contracted tightly close the shell.

Bivalve: A mollusk whose body is enclosed by a pair of hard shells.

Conglutinate: A mass of glochidia held together by mucous. These often look very similar to aquatic insects or worms.

Endangered: The species is threatened with extinction throughout all or a significant portion of its range.

Excurrent Siphon: An opening that expels the water cleaned of food and oxygen away from the mussels body.

Exotic Species: A species of animal or plant that has been introduced to an area outside of its native habitat.

Extirpated: The species is no longer found in this portion of its historic range.

Foot: Muscular organ that a bivalve mollusk uses for locomotion.

Glochidia: The bivalved larva of freshwater unionid mussels which are parasitic on fish.

Gravid: pregnant, carrying eggs

Hinge: the elastic part of the shell that unites the valves along the dorsal margin of the shell

Incurrent Siphon: An opening that brings the oxygen and food containing water into the mussels body.

Larva: Immature form of an animal.

Mantle: A thin tissue that surrounds the soft body of a mollusk. In most mollusks the mantle secretes a hard protective shell.

Mollusk: Soft bodied animal that posses a head, food, and a mantle.

Special Concern: The species is not endangered or threatened, although it is extremely uncommon, or has unique or highly specific habitat requirements and deserves careful monitoring of its status.

Threatened: The species is likely to become endangered within the foreseeable future throughout all or a significant portion of its range.

Valve: one of the two halves of the shell.