472 riSH HAICHERY MANAGKMENT 



Ascites The accumulation of serum-like fluid in the abdomen. 

 Ascorbic Acid Vitamin C, a water-soluble antioxident important for the 



production of connective tissue; deficiencies cause spinal abnormalities 



and reduce wound- healing capabilities. 

 Asphyxia Suffocation caused by too little oxygen or too much carbon 



dioxide in the blood. 

 Asymptomatic Carrier An individual that shows no signs of a disease 



but harbors and transmits it to others. 

 Atmosphere The envelope of gases surrounding the earth; also, pressure 



equal to air pressure at sea level, approximately 14.7 pounds per 



square inch. 

 Atrophy A degeneration or diminution of a cell or body part due to 



disuse, defect, or nutritional deficiency. 

 Auditory Referring to the ear or to hearing. 

 Autopsy A medical examination of the body after death to ascertain the 



cause of death. 

 Available Energy Energy available from nutrients after food is digested 



and absorbed. 

 Available Oxygen As used in this text, that oxygen present in the 



water in excess of the amount required for minimum maintenance of a 



species, and that can be used for metabolism and growth. 

 Avirulent Not capable of producing disease. 

 Avitaminosis (Hypovitaminosis) A disease caused by deficiency of one 



or more vitamins in the diet. 

 Axilla The region just behind the pectoral fin base. 



Bacteremia The presence of living bacteria in the blood with or without 

 significant response by the host. 



Bacterial Gill Disease A disease usually associated with unfavorable 

 environmental conditions followed by secondary invasion of opportun- 

 ist bacteria. See Environmental Gill Disease. 



Bacterial Hemorrhagic Septicemia A disease caused by many of the 

 gram-negative rod-shaped bacteria (usually of the genera Aeromonas or 

 Pseudomonas) that invade all tissues and blood of the fish. Synonyms: 

 infectious dropsy; red pest; fresh water eel disease; redmouth disease; 

 motile aeromonad septicemia (MAS). 



Bacterial Kidney Disease An acute to chronic disease of salmonids 

 caused by Renibacterium salmoninarum. Synonyms: corynebacterial kid- 

 ney disease; Dee's disease; kidney disease. 



Bacterin A vaccine prepared from bacteria and inactivated by heat or 

 chemicals in a manner that does not alter the cell antigens. 



