Student Glossary

Note to Teachers: Consider which of these terms you would like your class to commit to memory, and create a “short list” of this glossary for your students.

adaptation: Adjustment or modification of an organism to changes in the environment.
adipose fin: A small fatty fin found on the top back of salmon and trout between the dorsal fin and the tail (caudal fin). This fin is a key identification feature of hatchery and wild salmon or trout.
aerate: Supplying with oxygen; with water it is a process of exposing water to the air, usually by churning or breaking the surface of the water, such as waterfalls, riffles, etc..
alevin: Newly hatched fish with yolk sac attached. See sac fry.
algae: Simple plants that grow in water. They range from microscopic size to plant hundreds of feet long.
anadromous: Migratory. A fish that spawns in fresh water then migrates to the ocean, returning to fresh water as an adult to spawn. (From the Greek words for “up river”)
anal fin: Fin located on the bottom and near the back of the fish.
anglers: People who fish. Usually refers to recreational (sport) fishers using a rod and reel.
anthropologist: A person who studies human beings and human cultures.
aquatic: Water-related. Anything that lives in the water.
bar: The area at the mouth of a river where sediments are deposited.
barrier: Barricade; separator; blockage of a route.
Benthic: Bottom-dwelling.
brood fish/brood stock: Fish held in the hatchery to produce eggs like one would raise chickens for eggs.
buck: A male fish.
carbon dioxide: A gas (like oxygen is a gas) which is exhaled from animals and absorbed by plants.
carcass: Body of a dead animal; corpse; carrion.
carrying capacity: The number of fish or wildlife that can be supported by a given area of land or water.
cascades: A steep series of small waterfalls. It is the name given to thee mountain range that runs through the center of Washington and Oregon.
caudal fin: Another name for the tail of a fish.
char: A genus of small-scaled trout (Salvelinus).
commercial fishing: Fishing to sell the catch of fish for the market.
counter-shaded: Offset coloration allowing an animal to hide in its environment. Fish usually have darker tops and lighter bottoms, making it difficult to see them from above or below.
divide: The line that separates watersheds, usually a ridgetop.
domestication: To adapt an animal to life in association with humans.
dorsal fin: Dorsal means top. This is the large fin on the top of the back of a fish’s back.
ecological: How plants, animals and other living creatures interrelate to their environment.
ecology: The relationship or study of the relationship of a fish or animal to its environment.
eddy: A current of water (also could be air) which runs against the main current.
electromagnetic signals: Small electrical charges based on magnetic properties.
Endangered Species Act: A law that requires special protection for plant and animal populations that are in danger of becoming extinct.
estuary: The area where the tides of the ocean meet a river current.
environment: The total of all the things around you, both physical and biological.
erosion: The natural process of moving soil and rock material from any part of the earth’s surface.
evaporate: Change from a liquid or solid to a gas.
exploitation: Take for personal use without providing a benefit in return.
extinction: Gone forever.
eyed egg: A fish egg that has developed to the point where the dark eyes of the embryo can be seen through the shell.
fertile: An egg that has the potential to develop and hatch or an animal or fish that can produce
fertilize: Mix sperm and eggs. One sperm unites with (fertilizes) one egg to create a complete set of genetic instructions (genes).
fingerling: A small fish, up to one year of age. A small fish about the size of your little finger. A stage or size measurement in the growth of a fish.
foliage: Plants.
food chain: A chain or series of plants and animals where some feed on certain ones and are in tum eaten by others.
forb: A herbaceous plant other than grass growing on a field or meadow.
freshets: A stream created by overflow or runoff.
fry: Recently hatched fish, after yolk sac has been absorbed, and prior to the fingerling stage.
fungus: A type of lower plant (such as mold) that helps decompose organic matter.
gene: The unit of genetic information passed along from generation to generation through mating.
gills: The feathery organs of fish and other aquatic creatures that extract oxygen from the water and return carbon dioxide.
gillnet: Nets that capture fish as they try to swim through the holes in the net. Used mostly by commercial fishers.
gradient: Gradual change in coloration, slope, or pressure.
grading: The process of sorting fish by size.
ground water: Water that is contained in the soil or ground and is pumped out of wells.
habitat: The place where a fish or animal lives. It must include the necessary food, water, and shelter.
habitation: Occupancy; residence; moving in.
hatchery: Location for raising fish.
heath tray: Tray used in hatcheries to raise eggs to the fry stage.
hen: Female fish.
homing: Ability to return or locate “home,” or a desired location.
hydroelectric facility: A dam; a place where electricity is made by falling water.
ice age: A period in geologic time, more than 10,000 years ago, when nearly one quarter of the earth was covered with ice.
imprinting: Behavior in which the first response to a particular stimulus, early in life, becomes a fixed response to the same stimulus thereafter.
incubator: A human-made environment where eggs are placed to hatch.
incubation: The entire process of hatching an egg.
inorganic: Made from material that is not from an animal or plant
interspace: The areas on a fish between the parr marks.
invertebrate: Does not have a backbone.
juvenile: A young fish or animal that is not mature.
larvae: An immature stage of development in many kinds of organisms.
lateral habitat: The calm water areas along the edges of a stream.
lateral line: A sensitive line along the side of a fish which senses changes in pressure.
leaf litter: Old fallen decaying leaves.
liberation truck: The specially equipped tanker truck that hauls fish to the place they will be stocked.
life cycle: The stages of development from egg to adult.
limiting factor: Factors that reduce the populations of living organisms.
marked fish: A fish that has had a fin clipped off, a dye sprayed on, a tag attached, or a wire implanted so it can be identified at a later date.
mash: Food pellets fed to young fish at the hatchery.
maxillary: The upper jaw bone of vertebrates, including fish.
midge: The larval form of any two-winged fly.
migration: Traveling between seasonal habitats.
milt: A milky liquid from the male fish that contains sperm.
Miocene: The geologic time period between 12 million and 25 million years ago.
mortality: Death.
niche: The role that a fish or animal plays in the plant and animal community. The type of habitat it uses.
nutrients: Natural particles which are used by living organisms.
organic: Of plant or animal origin.
parasite: A plant or animal living in or off of another plant or animal, in a harmful way.
parr marks:Vertical lines on young fish which make them harder to see.
pectoral fin: Front steering fins on either side of a fish; corresponds to front legs.
pelvic fin: Lower fin on either side of a fish; corresponds to hind legs.
percolation: To trickle/flow through something.
pesticide: A substance that is poisonous to certain animals considered by humans to be pests.
physiological: Having to do with what goes on inside of a body.
plankton: A tiny animal or plant which floats in water.
pool: A still/calm place of water.
porous: Full of holes and allows liquid to pass through.
predator: An animal that eats another animal.
raceway: A rectangular hatchery pond where water enters at one end and leaves at the other.
rapid: Fast moving, churning water.
ray: The main supporting structures for fins of a fish, usually easy to see and count.
rearing: To raise young.
redd: The nest made by salmonids for their eggs.
reservoir: Storage place for water.
respiration: The process of getting oxygen into the blood, either from the air or water. Another word for breathing.
riffle: Fast, shallow waters of a stream.
riparian zone: The vegetated area next to a stream/ river.
run: A population of fish that returns from the ocean at about the same time headed for the same place.
run-off: Excess water beyond the normal flow of a stream.
salmonid: Any fish of the salmon or trout group.
sediment: Fine particles of rock and sand that collect along a river bottom.
seine: A net weighted at the bottom that hangs vertically in the water and catches fish when its ends are drawn together.
shelter: Cover. A place to hide, raise the young, or get protection from weather or predators.
silt: Tiny, fine particles, such as soil or sand, suspended in and deposited by water.
slime layer: The layer of mucous covering a fish that protects it from fungi, parasites, and disease.
smolt: A young salmon or trout that has turned a silvery color and is ready to migrate to the ocean.
spawn: The act of egg-laying by the female fish and fertilization
by the male fish.
species: A specific type of animal or plant that can breed and produce offspring only with its own kind.
sperm or milt: Milky substance produced by the male fish to fertilize eggs.
stocking: The process of releasing fish into a lake or stream.
storm drain: Drains from streets and parking lots that channel rain water directly into streams.
stream velocity: The speed and volume with which a stream flows.
streamline: A torpedo like shape that moves easily through the water.
substrate: Bottom material.
terrestrial: Belonging to the earth.
transpiration: An animal or plant giving off a watery vapor.
tributary: A side stream that joins a larger river.
turbulence: Uneven rough flow.
vent: The tube with which the female fish deposits her eggs.
watershed: The land area where water collects and flows.
weir: A fence or enclosure set in a waterway for capturing fish. Also, a dam or obstruction in a stream to raise the water level or divert its flow.
yolk sac: Sack attached to a newly hatched fish containing a balanced diet for its early growth.
zooplankton: Microscopic and other very small animals in water, many of which are larval forms.