head—tip of snout to edge of operculum Trunk—operculum to anus Tail—anus to caudal fin Mouth—take in food Maxilla—upper jaw Mandible—lower jaw external nares—dorsal on snout, 2, lead to olfactory sacs olfactory sacs—highly sensitive to dissolved chemicals in water external ear, eye lids—NONE internal ear—semicircular canals, function = balance and maintaining fishes position in water Operculum—behind eye, protects gills, Gills—4, gill arches and gill slits, function to take in oxygen from water, gill slits—space between gills gill archers—comblike respiratory gills under operculum branchiostegal membrane—lower edge of operculum, supported by rays of cartilage, one way valve, lets water out but not in lateral line—extends along whole side of body, series of water filled canals which communicate via pores with water Fins—dorsal, caudal, anal, pectoral, pelvic, fin rays, fin spines, function = steering, maintenance and equilibrium dorsal fin—2 on back, first dorsal fin has calcified spines, only fin not flexible or supported by soft rays caudal fin—end of tail anal fin—near urogenital opening pectoral fin—behind opercula, ventral to pelvic fin rays—allow fins to be flexible fin spines—several in first dorsal fin, run along anterior edge of other fins pelvic fin—below pectoral fin, Anus—excretion of waste urogenital opening—excretion of gametes for external fertilization Scales—thin, rounded, scale gets bigger (number of scales doesn't change during growth), growth rings—concentric circles in scales, count rings, rings formed in fall and winter thin, summer and spring thick mucus producing epidermis—seasy movement and protection against disease
muscle segment—Muscular segment of the posterior portion of the body; its zigzag arrangement contributes to efficient motion. Skull— Bony structure enclosing and protecting the brain. urogenital aperture—Opening common to the genital and urinary tracts allowing the evacuation of gametes and urine. air bladder—Flexible air-filled sac located above the viscera; it allows the fish to remain buoyant at a specific depth. vertebral column—Movable bony axis made up of various parts articulating with each other (vertebrae); it supports the skeleton and contains the spinal cord. spinal cord—Component of the nervous system made up of a soft fatty substance and forming a cylindrical stem inside the vertebral column. neural spine—Bony stem of the nervous system connected to the vertebral column and forming the skeleton. Kidney—Organ that eliminates metabolic waste and maintains the pressure of internal fluids. Intestine—Section of the digestive tract between the stomach and the anus where absorption of nutrients is carried out and waste is transformed into fecal matter. Stomach—Dilated section of the digestive tract preceding the intestine; it receives food to be digested. pyloric cecum—Lateral canal of the digestive tract where a part of digestion mainly occurs, as well as fermentation. Esophagus—Canal of the anterior portion of the digestive tract; it carries food to the stomach. Heart—Muscular organ helping blood to circulate. ventral aorta—Canal circulating the blood from the heart to the gills, then on through the head and the rest of the body. Gills—Respiratory and excretory organs (four pairs) each formed of two layers of filaments; they enable water to exchange oxygen and ammonium as it circulates over the gills. Tongue—Elongated movable mouthpart having a gustatory function; it allows the fish to swallow its food. olfactory bulb—Enlargement of the anterior terminal end of the olfactory nerve where its roots come together. olfactory nerve—Cranial cord connecting the brain to the olfactory bulb. Brain—Main organ of the nervous system that is made up of nerve centers; it is located in the upper portion of the head and is protected by the skull. Otolith—Small calcareous structure of the inner ear ensuring the fish’s equilibrium in the water. urinary bladder—Reservoir in which urine from the kidneys collects before being evacuated through the urogenital aperture. Liver—Viscera that secretes bile, among other substances; bile helps digestion. Spleen—Organ of the circulatory system where impurities in the blood are destroyed. Anus—Terminal orifice of the digestive tract enabling ejection of fecal matter. Eggs—In fish, the female produces eggs in the ovaries and the male produces soft roe in the testicles; the eggs and roe are expelled into the water, where fertilization occurs. first dorsal fin—Swimming appendage formed of a membrane and usually prickly rays located on the middle anterior dorsal portion of the body; it provides stability. second dorsal fin—Swimming appendage formed of a membrane and rays located on the middle posterior dorsal portion of the body; it provides stability.