Distinguishing between the abyssal macrourids Coryphaenoides yaquinae and C. armatus from in situ photography

► In situ images of Coryphaenoides yaquinae and C. armatus were compared. ► Image-specific morphometric characters were inadequate to distinguish species. ► Reflection of artificial light off the body revealed interspecific differences. ► Reflection characteristics were sufficiently consistent to differentiate the species. ► These data were corroborated by known bathymetric and geographic distributions.