Abstract

"There is evidence for interspecific correlations among population parameters in fish. Such correlations have been described from parameters including those produced through the von Bertalanffy model, natural mortality, age and length at maturity. The correlations have been used as practical tools to predict the dynamics and life history characteristics of understudied populations, and even to estimate maximum sustainable yield. The value of invariant proposed by Jensen (i.e., Lm/L∞ = 0.66) has not been tested for fish from the Eastern South Pacific: hence, we evaluated the value of invariant for Chilean fish resources to determine the average effect size, the homogeneity around the mean effect size, and variables which might moderate the effect size, if homogeneity does not exist. In order to examine this question we conducted a meta-analysis of studies examining Jensen's invariant (Lm/L∞ = 0.66), where we collected a total of 148 invariant values from 10 fish families. Significant differences were detected in these parameters between fish species, so the analysis was conducted with data pooled at the family level. The weighted average obtained with the random effects model was 0.61. The families Merlucciidae, Nototheniidae, Ophidiidae, Scombridae and Trachichthyidae showed a value of 0.66. The average for the Bramidae was 0.69, and for Carangidae, Clupeidae and Engraulidae was 0.46, 0.56 and 0.51 respectively. These results showed that the theoretical value of the invariant Lm/L∞ = 0.66 as proposed by Jensen, is not general to the commercially important fishes of the Eastern South Pacific."