Fishing Glossary
Lifecycle Termanology
Detritus: Small, loose pieces of decaying organic matter underwater.
Duns: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.
Emergence: The transformation of a nymph or pupa into the adult winged stage of an insect. The term may refer to the emergence of an individual, or the daily or yearly event in which all individuals of a species emerge.
Naturals: A natural is a real insect (or similar creature) a trout might eat. The term is used to specify the real thing as opposed to its artificial imitation.
Nymphs: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).
Piscivorous: Anything which eats primarily fish is a piscivore.
Spinner: There are two winged stages of adult mayflies. They emerge from the water as duns, molt on land (usually) into their fully mature stage, spinners. As spinners, they mate, lay eggs, and die.
Subimago: Mayfly nymphs emerge from the water into subimagoes, better known to anglers as "duns." They are a sexually immature, winged, recognizably adult stage and they must molt one more time into imagoes or "spinners" before they can mate.
Fly Fishing Terminology
Anadromous: Fish that live most of their adult life in saltwater but spawn in freshwater.
Angling: Sport fishing for enjoyment, catching one fish at a time using a hook.
Aquatic: Having to do with water.
Bait restrictions: Limitations to the type of bait sport anglers may use.
Barb: The spur found on the point of most fish hooks.
Carrying capacity: The number of species a specific areas habitat can support.
Catch and release: Sport angling for fish and releasing them back immediately. Some areas allow sport angling, but require release of fish, in these areas, specific types of tackle is required.
Creel: A fish basket or personal fish carrier used to carry fish when fishing on or near shore.
Daily catch and possession limits: Daily catch limits is the amount of fish, by species, that can be caught in one day. Possession limits refer to how many an angler may have in possession while in the field or during transport.
Downrigger: A fishing device used on boats that allows a troller to fish a lure at a constant specific depth.
Ecosystem: A complex ecological community or environment forming a functioning whole.
Edge effect: Where two habitat types join together resulting in increased diversity for vegetation and wildlife.
Epilimnion: The warm layer of surface water.
Ethics: Personal code of conduct based on respect for one's self, others, and your surroundings.
Fall overturn: A mixing or turning over of the water takes place in the fall and results in reoxygenation of the water.
Fillet: Removal of bones and skin from flesh of fish to prepare for cooking.
Fishing closures: Waters closed to fishing due to special biological, social or safety concerns.
Food chain: The chain of organisms in a community that produce food and consume it.
Fry: Life stage of salmonid fish still very young, but out of the redd and growing.
Game fish: Fish that are fished for as sport and subject to regulations of take.
Habitat: The area where organisms live. Must provide adequate food, water, shelter and space.
Hatchery: A facility where fish and raised for stocking.
Hypothermia: The rapid and abnormal chilling of the body.
Lateral line: A system of sense organs in fish: a series of pores or canals running along a line on each side of the body and on the head; detects pressure changes, including vibrations, in the water.
Lentic: Still water systems such as lakes and reservoirs.
Life vest: Personal floatation devices (PFD) to be worn while boating to keep person afloat if overboard.
Limiting factor: A biological limitation to a self-sustaining population.
Lotic: Moving water systems such as streams and rivers.
Lure: Any artificial bait used to attract and catch fish.
Maximum size limit: A fishing regulation which protects larger fish. Fish at or above stated size must be released.
Minimum size limit: A fishing regulation which protect smaller fish. Fish not meeting the minimum size must be released.
Niche: Organisms role, or job, in the ecosystem in which it lives.
Nongame: Fish not considered sport fish and generally not regulated.
PFD: Abbreviation for Personal Flotation Device: commonly called a life vest.
pH: The hydrogen ion content, or the acidity or alkalinity of any substance. Most fish prefer a neutral pH range, about 7. A low pH means acidic water; high pH is caustic or alkaline. Either condition in extreme can be harmful to fish.
Put and take fishery: An area where fish are stocked regularly with catchable size fish which are expected to be caught out by fall.
Recruitment: Natural reproduction of fish population.
Redd: The specific area where fish have deposited eggs for incubation.
Reservoir: Lake-like body of water created by damming of stream or river.
Riparian zone: The transition zone between the water and the upland zone. Can be identified by specific types of plants and soils.
Roe: Fish eggs
Sac fry: A life stage of young fish where the food sac has not been completely absorbed.
Size limits: Fishing regulations which limits anglers to keep fish based upon size.
Slot limit: Fishing regulation which requires release of fish within a listed size range (or slot).
Smolt: Life stage of anadromous fish; sub-adult salmon or steelhead ready to begin journey to ocean.
Smoltification: Process of physical changes anadromous fish must go through which allows them to adapt to salt water environments.
Spawning: Reproductive activity of fish; the act of releasing eggs into the water by female fish for fertilization by male fish.
Species: A biological classification of plants and animals.
Sporting: Showing good sportsmanship and ethics in pursuit of game fish.
Stocked: Populating a body of water with fish reared in hatcheries.
Stratification: Layering of a lake, by temperature, during warmer seasons.
Taxonomist: A scientist who classifies fish or animal by kingdom, phylum, class, order, family, and species.
Terminal tackle: The hooks, weights, swivels, and other tackle attached on or near the end of the fishing line.
Terrestrial: Things of the land.
Test: Line strength as stated on the label.
Thermocline: The layer of water where temperature rapidly changes from warmer to colder water.
Treble: A hook with three points used on many lures.
Wetland: Area covered all or part of the year by water. Can be identified by typical plants and soil types.
Winter-kill: Fish kill in shallow ponds or reservoirs due to oxygen depletion.
Questions or Reservations
Online Reservation RequestPhone: 1 208.558.7525
Fax: 1.208 558.7932
Toll Free: 1 800.788.4479
Email:info@henrysforkanglers.com
Mailing Address:
Henry's Fork Anglers,
3340 Hwy 20,
Island Park, Idaho 83429


