2 



Hatchery Operations 



Production Methods 



The information presented in this chapter will enable the fish culturist to 

 employ efficient management practices in operating a fish hatchery. Proper 

 feeding practices, growth projections, and inventory procedures are a few 

 of the essential practices for successful management. Although particular 

 species are used in examples, the concepts and procedures presented in this 

 chapter can be applied to warmwater, coolwater, and coldwater fish cul- 

 ture. 



Length- Weight Relationships 



Increase in fish length provides an easily measured index of growth. 

 Length data are needed for several aspects of hatchery work; for example, 

 production commitments are often specified by length. On the other hand, 

 much hatchery work, such as feed projections, is based on fish weight and 

 its changes. It is very useful to be able to convert back and forth between 

 length and weight without having to make measurements each time. For 

 this purpose, standardized length-weight conversion tables have been avail- 

 able for several years. These are based on the condition factor, which is the 

 ratio of fish weight to the length cubed. A well-fed fish will have a higher 



60 



