1. Introduction
The use of anesthetics has facilitated a variety of important
procedures in fisheries research. These procedures include making
measurements, administering tags, extracting tissue samples,
and minor surgery. When properly applied, anesthesia calms the
fish, reduces its movement, and minimizes stress and pain. These
attributes increase researchers’ ability to handle fish without injuring
themselves or the fish. Furthermore, anesthesia is required by
Institutional Animal Care and Use Committees (IACUC) following
guidelines of the Association for Assessment and Accreditation of
Laboratory Animal Care International (AAALAC) and regulations
provided by the Animal Welfare Act (Garber et al., 2011).
Many different methods of anesthetization have been tested on
fishes, but technical or legal reasons limit applications in the field.
When tagging or surgery is involved, stage-4 anesthesia should be
induced, which is characterized by complete loss of equilibrium,
loss of swimming motion, and weakened opercular movements