Careproctus io (Teleostei: Liparidae), a New Snailfish from the Western North Pacific, with Comments on Generic Limits

The new snailfish Careproctus io is described on the basis of three specimens collected from the western North Pacific, off northeastern Honshu Island, Japan. The new species can be distinguished from congeners by the following characters: vertebrae 40–42; dorsal-fin rays 36 or 37; anal-fin rays 30; pectoral fin deeply notched with 28 or 29 rays, lower lobe reaching to anal-fin origin; large pelvic disk 34.2%–34.5% HL (10.3%–10.9% SL); teeth strongly trilobed on both jaws, inner teeth weakly trilobed or shouldered; cephalic pore pattern 2-6-7-2, chin pores paired; gill slit above pectoral-fin base; body bright red, non-variegated in life. Species of Careproctus Krøyer, 1862 typically have fewer pectoral-fin rays than anal-fin rays, although some recently-described species, including the present new species, have similar ray counts in both fins. The relationships between such counts, as well as pelvic disk size, are investigated for various snailfish, genera, and the generic limits of Careproctus discussed.