Body shrinkage in young Walleye, Stizostedion vitreum, preserved with AFA, formalin, ethanol and quick freezing

Abstract

Changes in total length of larval and juvenile Walleye, Stizostedion v. vitreum , resulting from delayed fixation and the use of various fixatives were examined over a three-day period. Delayed fixation for up to 30 min after death had no significant effect upon percent shrinkage. Fixation in 5% buffered formalin caused body shrinkage of 2.0%, 2.6% and 7.6% in 26-, 12- and 5-day-old fish, respectively. Shrinkage could be reduced significantly only for the 5-day-old fish by fixing them in AFA (alcohol-formaldehyde-acetic acid) rather than in formalin. Other fixative treatments, such as 70% ethanol or quick-freezing, were less effective in limiting shrinkage in total length