Methods for Fish Biology

Chapter 20: Maintaining Fishes for Research and Teaching

Robert R. Stickney and Christopher C. Kohler


Laboratory research and controlled field experiments with live fishes necessitate the use of culture systems to maintain the animals before, during, and between experimental trials. Experiments often require specialized apparatus and we have not attempted to describe in detail the array of experimental fish-holding chambers that have been used. Instead, our purpose is to provide information about the general types of water systems that have been successfully employed and about other factors that must be taken into account when fish are maintained in captivity.

It is very important in fish culture to minimize stress on the animals. Stressed fish may behave abnormally and are much more susceptible to diseases and parasites than fish which are held under optimum conditions. Any behavioral, disease-related, or physiological manifestation of stress can render a group of fish useless for controlled experiments. Maintenance of fish under optimum conditions helps ensure that the responses seen during an experiment reflect the treatments and are not artifacts of holding stress. Some of the principal causes of stress in fish are handling, mechanical damage, poor water quality, dietary imbalances, diseases, parasitism, and extremes of or abnormal changes in light and temperature (see Chapter 14 and Simco et al. 1986). Culture systems should be designed and managed for the particular species being held.

Regulations governing the maintenance of laboratory animals have been promulgated in some nations, including the USA. The main purpose of such regulations is to provide humane treatment of laboratory animals. At least some U.S. government agencies apply the same doctrine to fishes that they do to higher vertebrates, requiring that certain standards be met in the care and handling of laboratory animals. Regardless of the circumstances and applicable governmental regulations, ethics dictate that fishes maintained for research or teaching purposes should be treated humanely.