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

The anterior dorsal fin usually possesses spines, while the posterior only has rays.

The legs were yellow, not striped, and possessed thin spines.

Almost all the major fins possess spines and venom glands.

Females possess strong sphenotic and preopercle spines and a highly distensible stomach.

However U. phantasticus possesses more, and longer, spines on the head, body and trunk.

All toadfishes possess sharp spines on the first dorsal fin and on the opercle (gill cover).

They possess spines on the pygidium and short, thick antennae.

Most cacti possess spines, some large enough to cause serious wounds.