Morphometric Differences between Golden Redfish ( Sebastes marinus ) and Beaked Redfishes ( S. mentella and S. fasciatus )

Abstract

Morphometric characters were investigated to provide criteria, in addition to morphological differences that are presently employed, for species identification of Atlantic redfishes (genus Sebastes). The study involved the analysis of morphometric data for a sample of redfish which was collected in the Labrador-Newfoundland region in 1958 and initially separated into two groups (Sebastes marinus and beaked redfish) on the basis of color, eye size and beak shape. Standard length was used as a covariate to adjust the morphometric data because S. marinus were on the average largerthan beaked redfishes. Discriminant analyses of (a) 17 morphomet-ric characters resulted in an 11-variable discriminant function where 65% of the variability was explained by the groups, (b) the two traditional discriminatiors (length of symphyseal tubercle and width of orbit) resulted in a function where 56% of the variability was explained by the groups, and (c) the remaining 15 morphometric characters resulted in a 9-variable function where 58% of the variability was explained by the groups. The results demonstrated good (87-90%) separation of golden redfish (S. marinus) and beaked redfishes (S. mentella and S. fasciatus). Length of symphyseal tubercle (beak), orbit width, body depth at the position of the pectoral fins, interorbital width, depth of caudal peduncle, and width of pectoral fin base were determined as good morphometric discriminators.