Fish Hatchery Management - fisheries & aquaculture

494 trsH HATcHERY MANAGEMENTRandom Mating Matings without consideration of definable characteristicsof the broodfish; nonselective mating.Ration A fixed allowance of food for a day or other unit of time.RayA supporting rod for a fin. There are two kinds: hard (spines) andsoft rays.Rearing Unit Any facility in which fish are held during the rearingprocess, such as rectangular raceways, circular ponds, circulation raceways,and earth ponds.RecessiveCharacter possessed by one parent that is masked in theprogeny by the corresponding alternative or dominant characterderived from the other parent.Reciprocal Mating (Crosses) Paired crosses in which both males andfemales of one parental line are mated with the other parental line.Reconditioning Treatment Treatment of water to allow its reuse forfish rearing.Rectum Most distal part of the intestine; repository for the feces.Red Pest See Motile Aeromonas Disease.Red Sore Disease Sae Vibriosis.Redd Area of stream or lake bottom excavated by a female salmonidduring spawning.Redmouth DiseaseAn original name for bacterial hemorrhagic septicemiacaused by an infection of Aeromonas hydrophila specifically. Synonyms:motile aeromonas disease; bacterial hemorrhagic septicemia.Residue, Tissue Quantity of a drug or other chemical remaining inbody tissues after treatment or exposure is stopped.Resistance The natural ability of an organism to withstand the effectsof various physical, chemical, and biological agents that potentially areharmful to the organism.Resistant, Drug Said of a microorganism, usually a bacterium, that cannotbe controlled (inhibited) or killed by a drug.Reuse, Recycle The use of water more than one time for fish propagation.There may or may not be water treatment between uses and differentrearing units may be involved.Riboflavin An essential vitamin of the B-complex group (B2).RoccalRoeRoundwormSee Quaternary Ammonium Compounds.The eggs of fishes.SaeNematoda.Sac FryA fish with an external yolk sac.Safe Concentration The maximum concentration of a material thatproduces no adverse sublethal or chronic effect.SalinityConcentration of sodium, potassium, magnesium, calcium,