The smooth lumpfish is a mysterious species of which
very little is known. Only a few specimens have ever been caught and so nothing
is known of its biology.
This species can be distinguished from other lumpfish by the gill opening above
its pectoral fin, and by the five blunt tubercles found on the anterior part of
its body. Its first dorsal fin is rounded and fleshy with 6 spines while the second
has 1213 soft rays. The caudal and anal fins are rounded, with the anal
fin containing 1012 rays. Its pectoral fins are large and fan-like with
2324 rays. Its body is shaped much like a tennis ball with fins, mouth and
eyes. Its overall body colour is likely brownish-grey, and it grows to a length
of just 6.1 cm.