Determination of the best length measurement of fish

Abstract

Standard (SL), fork (FL) and total lengths (TL) of three common freshwater fish species, goldfish Carassius auratus (L.), gibel carp Carassius gibelio (L.) and common carp Cyprinus calpio (L.) were examined to determine the most consistent length measurement of fish and possible bias source of multiple measurements of the same sample by different persons based on statistical comparisons. Index of Average Error (IAE) suggested that measurement of TL had significantly lower average errors compared to SL and FL for all species (p<0.001). The length-length linear regressions were all highly significant (p<0.001) and analysis of covariance (ANCOVA) revealed no significant differences in the slope of length-length relationships of the measurements among researchers for all fish species (p>0.05). Analysis of variance (ANOVA) results indicated that there was no significant difference between the personal measurements of different type of lengths. The best length measurement of fishes is discussed.