“He described it as looking like a giant pleco.”
Turns out the fish was a northern kingfish.
"Northern kingfish are part of the drum family, Sciaenidae, which also includes weakfish, spot, Atlantic croaker, red drum and black drum. Since they lack an air bladder, Northern kingfish do notmake typical "drumming" sounds like other members of the drum family, but they can vocalize somewhat by grinding their pharyngeal (throat) teeth.
"Notable characteristics are the long spine on the first dorsal fin and a barbel on the chin. Dark, irregular bars are present along the body of the fish. The first two bars form two distinct V-shapes. The bold markings and a dark longitudinal stripe behind the pectoral fins distinguish it from the two other species of kingfish. The markings on Southern kingfish and Gulf kingfish are not nearly as prominent and do not form the V-shaped pattern.
"Northern kingfish can grow 18 inches long and can weigh up to three pounds, but greater lengths and weights have been reported. Commonly, these fish range from 10 to 14 inches long and weigh from one-half to 1.5 pounds. The largest ever recorded anywhere, a three-year-old female caught in a commercial gill net, was more than 21 inches long and weighed 3.3 pounds."
Description from: NJFishandWildlife.com