496 FISH HATCHERY MANAGEMENT 



Serum The fluid portion of blood that remains after the blood is allowed 



to clot and the cells are removed. 

 Settleable Solids That fraction of the suspended solids that will settle 



out of suspension under quiescent conditions. 

 Shocking (Eggs) Act of mechanically agitating eggs, which ruptures the 



perivitelline membranes and turns infertile eggs white. 

 Short Bath A type of bath most useful in facilities having a controllable 



rapid exchange of water. The water flow is stopped, and a relatively 



high concentration of chemical is thoroughly mixed in and retained 



for about 1 hour. 

 Side Effect An effect of a chemical or treatment other than that 



intended. 



Sign Any manifestation of disease, such as an aberration in structure, 



physiology, or behavior, as interpreted by an observer. Note the term 



"symptom" is only appropriate for human medicine because it 



includes the patient's feelings (sensations) about the disease. 



Silt Soil particles carried or deposited by moving water. 



Single-pass System A system in which water is passed through fish 

 rearing units without being recycled and then discharged from the 

 hatchery. 



Sludge The mixture of solids and water that is drawn off a settling 

 chamber. 



Smolt Juvenile salmonid at the time of physiological adaptation to life 

 in the marine environment. 



Snout The portion of the head in front of the eyes. The snout is meas- 

 ured from its most anterior tip to the anterior margin of the eye 

 socket. 



Soft-egg Disease Pathological softening of fish eggs during incubation, 

 the etiological agent(s) being unknown but possibly a bacterium. 



Soft Fins Fins with soft rays only, designated as soft dorsal, etc. 



Soft Rays Fin rays that are cross-striated or articulated, like a bamboo 

 fishing pole. 



Solubility The degree to which a substance can be dissolved in a liquid; 

 usually expressed as milligrams per liter or percent. 



Spawning (Hatchery context) Act of obtaining eggs from female fish 

 and sperm from male fish. 



Species The largest group of similar individuals that actually or poten- 

 tially can successfully interbreed with one another but not with other 

 such groups; a systematic unit including geographic races and 

 varieties, and included in a genus. 



Specific Drug A drug that has therapeutic effect on one disease but not 

 on others. 



Spent Spawned out. 



