Pelvic girdle shape predicts locomotion and phylogeny in batoids

ABSTRACT In terrestrial vertebrates, the pelvic girdle can reliably predict locomotor mode. Because of the diminished gravitational effects on positively buoyant bony fish, the same relationship does not appear to exist. However, within the negatively buoyant elasmobranch fishes, benthic batoids employ pelvic fin bottom‐walking and punting as primary or supplementary forms of locomotion. Therefore, in this study, we employed geometric and linear morphometrics to investigate if their pelvic girdles exhibit shape characteristics similar to those of sprawling terrestrial vertebrates. We tested for correlates of pelvic girdle shape with 1) Order, 2) Family, 3) Swim Mode, and/or 4) Punt Mode. Landmarks and semilandmarks were placed along outlines of dorsal views of 61 batoid pelvic girdles (3/3 orders, 10/13 families, 35/72 genera). The first three relative warps explained 88.45% of the variation among individuals (P