Abdominal
   referring or pertaining to the belly.

Adipose fin
   fleshy, ray-less fin on the midline of the back of fish, between the dorsal and caudal (tail) fins. Found almost exclusively on the Salmonid    Family of fishes.

Anal fin
   the un-paired fin on the underside of fish, behind the vent.

Anadromous
   ascending rivers from the sea for breeding (not resident).

Anterior
   front portion.

Barbel
   an elongated, hair-like projection, usually about the mouth, chin or nose as in cods and sturgeons (Scott Crossman 1998).

Branchiostegal
   rays bones that are ventral (under) to the opercles (gill covers) which support gill membranes.

Caudal fin
   the tail fin.

Caudal peduncle
   the narrow area of the body from the posterior (back) end of the anal fin to the base of the caudal (tail) fin.

Compressed
   squeezed together or narrow from side to side, flattened laterally.

Concave
   curved inwards (hollowed) usually used in reference to the edge of dorsal fin or top of fish’s head.

Convex
   curved outwards (arched) usually used in reference to edge of dorsal fin or the top of fish’s head.

Depressed
   flattened or pushed inward.

Diffuse
   spread out, not concentrated.

Dorsal
   referring or pertaining to the back.

Dorsal fin
   unpaired fin atop the back of fish.

Fin ray
   a boney (or cartilage) rod supporting the fin membrane.

Fontanelle
   an aperture or opening in a bony surface, as in the upper skull of some suckers.

Fork length
   the distance from the tip of the nose to inside arch, or the middle of the fork of the caudal (tail) fin.

Fry
   a life history stage of a fish, young fish, newly hatched, after yolk is used up and is actively feeding.

Gape, width of
   the greatest transverse distance across the opening of the mouth.

Gill arch
   one of the bony (or cartilage) arches or curved bars extending dorsoventrally (out the side) and placed one behind another on each side
   of the pharynx (throat) and supporting the gills.

Gill cover
   the bones (or cartilage) of the head that cover the gills, “opercle” or operculum.

Gill rakers
   anterior (front) knobby or comb-like projections from the gill arch.

Glide
   slow moving water with a smooth continuous movement.

Head length
   the distance from the tip of the snout or upper lip to the most distant point of the opercular membrane (gill cover).

Hypural notch
   the point between the end of the body vertebrae and the beginning of the caudal (tail) fin, the crease in the caudal peduncle (base of
   tail area) made by bending the caudal (tail) fin from one side or another.

Inferior
   in reference to mouth when snout projects beyond lower jaw (Scott Crossman 1998.) and when it is in a ventral or generally horizontal position.

Isolated
   untypical or unique, or set apart from others, or selected from among others.

Juvenile
   young.

Lateral line
    a visible line along the size of a fish consisting of a series of pore-like sensory organs acting as vibration receptors, or like sonar.

Laterally
   from the side.

Mandible
   the lower jaw.

Maxillary
   the lateral bones of the upper jaw.

Melanophore a black pigmented cell.

Mottled
   an irregular arrangement of spots or patches of colour.

Opercle (operculum)
   the large posterior bone of the gill cover.

Origin (of fin)
   the anterior end of a fin’s base.

Parr
   Life stage of salmonid fishes, first or second year of life, marked with parr marks (Scott Crossman 1998).

Parr marks
   dark vertical marks on sides of young salmonid fishes (Scott Crossman 1998) that provide camouflage from predation.

Pectoral fins
   the paired fins directly behind the head, attached to the pectoral girdle at the sides of the body.

Pelvic Fins
   the paired ventral (towards the back) fins generally positioned between the pectoral and anal fins.

Pharynx
   the throat.

Pool
   a deep place in a river.

Posterior
   behind.

Premaxillary
   either of the paired bones at the front of the upper jaw.

Protrude
   extend beyond or above a surface; to project outwards.

Protrusible
   adapted or able to be protruded (protractile).

Pyloric Ceacae
   Spaghetti-like extensions located at the base of the intestine which stores essential nutrients from food.

Resident
   not migratory.

Smolt
   a young salmon which has gone through physiological changes (including enlargement of the thyroid gland, loss of parr marks,
   appearance of silvery scales, and development of excretory salt cells) prior to downstream migration from parental stream.

Snout
   part of the head of a fish in front of the eyes

Spine
   an unsegmented, never branched and usually stiff support of the fin, rod-like.

Sucking disk
   the expanded region (open armed with rasping teeth) about the mouth of an adult lamprey. Looks like a suction-cup with teeth.

Suborbital
   below the eye.

Subterminal
   pertaining to a mouth which opens slightly ventrally (rather than opening at the anterior tip pf the head), with lower jaw
   sometimes closing within the upper jaw. In reference to mouth, snout slightly overhangs lower jaw.

Taxonomy
   classification, especially in biology and the principles of this.

Terminal
   in reference to mouth, both lower and upper jaw comes together without hanging over or under either jaw.

Total length
   the distance from the anteriormost projection of the head to the farthest tip of the caudal (tail) fin, when the lobes of the fins are
   squeezed together.

Truncate
   having an end even or square, as if cut off, as in the caudal (tail) fin.

Vent
   word used for external opening of rectum.

Ventral
   of the front or lower surface of the mouth.