HATCHERY REQUIREMENTS 51 



Table 6 summarizes some of the characteristics of the various rearing 

 units that have been described. 



Biological Design Criteria 



Every species of fish has basic environmental requirements and each has 

 optimum conditions under which it thrives and can be efficiently cultured. 

 Biological criteria are essential in the design of any fish culture facility and 

 these criteria must be recognized before a successful fish rearing program 

 can be developed. The following comments are abstracted from 

 Nightingale (1976). 



Information required in designing a facility includes fishery management 

 needs, fish physiology, chemical requirements, disease, nutrition, behavior, 

 genetics, and fish handling and transportation. 



These criteria must be developed for each species to be cultured. The 

 fishery management criteria include identification of the species to be 

 reared, desired sizes for production, and desired production dates. Manage- 

 ment criteria are usually listed as the number and length (or weight) of fish 

 that are required on certain dates. Physiological criteria include oxygen 

 consumption for various fish sizes and optimum temperatures for 

 broodstock holding, egg incubation, and rearing. Required rearing space, 

 water flows, and spawning and incubation methods are included in these 

 criteria. Chemical criteria include water quality characteristics that affect 

 the species of fish to be reared, such as tolerable gas saturation, pH, and 

 water hardness. Disease criteria include methods for disease prevention and 

 treatment. Nutrition criteria involve the types of feeds, feeding rates, and 

 expected food conversions at different temperatures and fish sizes. 

 Behavior criteria are needed to identify special problems such as cannibal- 

 ism and excessive excitability; for example, a decision may be made to use 

 automatic feeders to avoid a fright response. Genetic criteria involve 

 selection of specific strains and matching of stocks to the environment. 

 Transportation and handling criteria involve the acceptable procedures and 

 limitations for handling and moving the fish. 



The application of these criteria to the particular circumstances at each 

 hatchery can result in a biologically sound culture program. A program can 

 be developed by combining the management and physiological criteria 

 with the particular species and water temperatures to be utilized. Rearing 

 space and water flow requirements can be defined and combined with the 

 other criteria to establish a suitable hatchery design. 



Good program development for fish hatchery design should include, in 

 addition to biological criteria, adequate site evaluation, production alterna- 

 tives, and layout and cost estimates. 



