Fish Hatchery Management - fisheries & aquaculture

470 FISH HATCHERY MANAGEMENTAcute ToxicityCausing death or severe damage to an organism by poisoningduring a brief exposure period, normally 96 hours or less. SaeChronic.AdaptationThe process by which individuals (or parts of individuals),populations, or species change in form or function in order to bettersurvive under given or changed environmental conditions. Also theresult of this process.Adipose Fin A small fleshy appendage located posterior to the maindorsal fin; present in Salmonidae and Ictaluridae.Adipose Tissue Tissue capable of storing large amounts of neutral fats.Aerated LagoonAerationA waste treatment pond in which the oxygen requiredfor biological oxidation is supplied by mechanical aerators.The mixing of air and water by wind action or by air forcedthrough water; generally refers to a process by which oxygen is addedto water.Aerobic Referring to a process (for example, respiration) or organism(for example, a bacterium) that requires oxygen.AirThe gases surrounding the earth; consists of approximately 78'ftnitrogen, 2l()ir oxygen, 0.9'lir argon, 0.03'l; carbon dioxide, and minutequantities of helium, krypton, neon, and xenon, plus water vapor.Air Bladder (Swim bladder). An internal, inflatable gas bladder thatenables a fish to regulate its buoyancy.Air StrippingAlevinRemoval of dissolved gases from water to air by agitationof the water to increase the area of air-water contact.A life stage of salmonid fish between hatching and feeding whenthe yolk sac still is present. Equivalent to sac fry in other fishes.Algal BloomA high density or rapid increase in abundance of algae.Algal Toxicosis A poisoning resulting from the uptake or ingestion oftoxins or toxin-producing algae; usually associated with blue-greenalgae or dinoflagellate blooms in fresh or marine water.Alimentary Tract The digestive tract, including all organs from theAliquotAlkalinitymouth to the anal opening.An equal part or sample of a larger quantity.The power of a mineral solution to neutralize hydrogen ions;usually expressed as equivalents of calcium carbonate.Amino Acid A building block for proteins; an organic acid containingone or more amino groups (-NH2) and at least one carboxylic acidgroup (-COOH).AmmoniaThe gas NH1; highly soluble in water; toxic to fish in theun-ionized form, especially at low oxygen tensions.Ammonia Nitrogen Also called total ammonia. The summed weight ofnitrogen in both the ionized (ammonium, NH.,+) and molecular (NH,)forms of dissolved ammonia ( NHn-N plus NH3-N). Ammoniavalues are reported as N (the hydrogen being ignored in analyses).