Key to Northeast Pacific Bathyraja skates (Modified after Ebert et al., 2017)

1 Scapular thorns present................................................................................. 2

- Scapular thorns absent................................................................................. 4

2 Dorsal surface with a discontinuous row of median thorns......................... ..Bering Skate, Bathyraja interrupta

- Dorsal surface with continuous row of median thorns......................................................... 3

3 Ventral surface white except for snout, posterior disc margins, pelvic fins, anal area, and underside of tail, which are prominent dark brown or gray…........................................................Aleutian Skate, Bathyraja aleutica

- Ventral surface white with occasional brown blotches on tail….................... Sandpaper Skate, Bathyraja kincaidii

4 Disc thorns present....................................................... Deepsea Skate, Bathyraja abyssicola

- Disc thorns absent..................................................................................... 5

5 Ventral surface coarsely textured, very rough to the touch...................Pacific White Skate, Bathyraja spinosissima

- Ventral surface smooth to the touch....................................................................... 6

6 Dorsal and ventral colors different; dorsal coloration uniformly brown above, ventral surface white except for tail, pectoral fins, and pelvic region, which are brown.................................... Fine-Spined Skate, Bathyraja microtrachys

- Dorsal and ventral colors similar; uniformly plum brown to black, except for occasional white blotches on abdomenRoughtail Skate, Bathyraja trachura