[2] The flattened pectoral fin disc of the Pacific white skate is slightly wider than long, with broadly rounded tips.

Adult males possess alar spines (on the dorsal surface of the pectoral fins near the tips).

Like other skates they are oviparous; the egg cases are olive green in color and longitudinally striated, with horn-like projections on the shell.

Its species name, spinosissima, comes from the Latin spinosus meaning "thorny", referring to its covering of dermal denticles.

[3] In 2018, scientists found numerous bag-shaped eggs in proximity to hydrothermal vents near the Galapágos Islands.