HADDOCK (Gadus aeglefinus), a fish which differs from the cod in having the mental barbel very short, the first anal fin with 22 to 25 rays, instead of 17 to 20, and the lateral line dark instead of whitish; it has a large blackish spot above each pectoral fin - associated in legend with the marks of St Peter's finger and thumb, the haddock being supposed to be the fish from whose mouth he took the tribute-money.
Genera: Callionymus, Uranoscopus, Trachinus, Gadus, Blennius.
The genus Gadus is characterized by having three dorsal and two anal fins, and a truncated or notched caudal fin.
The cod, Gadus morrhua, possesses, in common with the other members of the genus, three dorsal and two anal fins, and a single barbel, at least half as long as the eye, at the chin.
COAL-FISH (Gadus vixens), also called green cod, black pollack, saith and sillock, a fish of the family Gadidae.