The caudal fin is crescent-shaped, strengthened at the base by two short ridges on each side.
This type of caudal fin must be regarded as secondary, the Gadidae being, no doubt, derived from fishes in which the homocercal fin of the typical Teleostean had been lost.
The variety most highly prized has an extremely short snout, eyes which almost wholly project beyond the orbit, no dorsal fin, and a very long threeor four-lobed caudal fin (Telescope-fish).
The dorsal crest is continued round both extremities, becoming expanded to form the rostral fin in front and the caudal fin behind.
The infection has reached the fish's body A extreme example of fin rot of the caudal fin.
