REDUNDANCY IN MORPHOLOGICAL COVARIATION PATTERNS BETWEEN Colossoma macropomum AND Piaractus orinoquensis

Currently, great importance has been given to the study of external morphology, especially in fish, when it is used as a means of identifying hybrids. However, in fish morphometry, multicollinearity, which refers to redundant information, that is, overlapping covariates (distances between homologous points) is a problem generally present in morphological covariation patterns. In order to have an overview of the existing collinearity diagnostic measures together with critical values commonly used to evaluate existence of collinearity among the covariates, this research considers the study of multicollinearity in the truss protocol on 92 specimens of Colossoma macropomum and Piaractus orinoquensis. The diagnostic measures used were those included in the R mctest package; classified into general and individual measures. Multicollinearity (redundant measurements in the "truss protocol") was detected in morphological covariation patterns between C. macropomum and P. orinoquensis specimens. Only distances associated with morphological covariation patterns that make a difference in the head area, in the area of the bases of the fins of the abdomen and in the anterior part of the fish, did not constitute redundant morphological information in the morphological covariation patterns of this species. The use of VIF is recommended as a measure to identify redundant information associated with the external morphology of C. macropomum and P. orinoquensis.