The weakfish is omnivorous and feeds on crabs, shrimp, other crustaceans, mollusks and small fishes like herring, menhaden, silversides, killifish and butterfish which it may catch in midwater or at the surface. These fish may be taken at any level from the bottom to the surface by chumming from a drifting or anchored boat or by trolling, jigging, or surf fishing. Conventional, spinning, and fly tackle may be used. They may also be taken from bridges, docks, and piers. When hooked on light tackle the weakfish is prone to give a long initial run with sudden, unpredictable changes in direction. It is reputed to be the gamest species of the Cynoscion genus. The following are fishing methods used to catch this fish:
The lower jaw of the weakfish clearly projects beyond the upper jaw. Two large, recurvate canine teeth in the front of the upper jaw stand out noticeably. The first dorsal fin has 10 spines. The second has one spine and 26-29 soft rays. The anal fin has two spines and 11-12 rays. The scales are ctenoid and extend onto the soft dorsal and anal fins. In the similar looking spotted seatrout (Cynoscion nebulosus) the scales do not extend onto the fins. Also, there are 11-13 gill rakers on the lower limb of the first gill arch in the weakfish, but only 8-9 in the spotted seatrout. Numerous small spots of black, olive or bronze are set close together on the upper flanks of the weakfish and seem to form wavy diagonal lines. The spots do not extend onto the tail or the second dorsal fin as they do in the spotted seatrout, nor are they as large or as widely spaced. There is sometimes a black margin on the tip of the tongue.