Black carp and grass carp morphometric measurements

Black carp Mylopharyngodon piceus and grass carp Ctenopharyngodon idella are morphologically similar species imported from eastern Asia to North America as biological control organisms. Preferred identification methods are coloration and pharyngeal tooth form. Grass carp possess serrated teeth and black carp molariform teeth. Examination of pharyngeal teeth causes extensive damage to a specimen, and is labor and time intensive. Coloration can vary within a species and fades with preservation. We present a suite of external characteristics consisting of a truss network canonical variate analysis of distance measurements among landmarks on the lateral view of the head of each fish, the ratio of head length to mouth width, anterior lateral line angles among scales, and the visible presence of the premaxilla viewed from the dorsum that can be applied for identification.