Bivalve - mollusk with a shell made of two hinged valves

Channelization - the straightening and/or deepening of a river channel

Endangered - a species faced with the danger of extinction

Extinct - a species that no longer exists

Extirpated - a species that has been eliminated from a particular area, but still exists somewhere else

Exotic - from another part of the world; foreign

Glochidium - the larva of a freshwater mussel (Superfamily Unionoidea) that generally lives as a temporary parasite on a host fish

Hermaphrodite - an animal or plant normally having both male and female reproductive organs

Introduced - brought in and established in a new place or surroundings

Larva - the newly hatched, immature form of an animal that undergoes metamorphosis, differing markedly in form or appearance from the adult

Metamorphosis - a marked change in the form or structure of an animal occurring after birth or hatching (vt. metamorphose)

Mollusk - soft-bodied animal with a muscular head and foot and a mantle, which usually secretes a protective shell

Parasite - an organism that grows, feeds, and is sheltered on or in a different organism (host) while contributing nothing to the survival of the host

Pseudocardinal Teeth - structures resembling teeth used in some species to hold the shell together

Siltation - deposition of fine mineral particles (silt) on the beds of streams or lakes

Spawn - to deposit sperm or eggs into the water

Threatened - a species likely to become endangered in the foreseeable future