To about 6.5 ft (2m).
- First and second dorsal fins, pectoral fins, and lower lobe of caudal fin black-tipped (black markings may fade in adults; may be indistinct in juveniles)
- Anal fin white
- First dorsal fin fairly large with short free tip, originating slightly over or behind insertion of pectoral fins along inner margin, apex pointed
- Color dark gray, bluish-gray, to dusky bronze above, with light, conspicuous wedge-shaped band or Z-shaped line on sides beginning near pectoral fins, gradually widening rearward to pelvic fins to merge with white on belly
- No interdorsal ridge
Massachusetts to Brazil, including Gulf of Mexico and Caribbean Sea. Rare north of Delaware.
Shallow coastal and continental shelf waters; surface offshore. Common near river mouths, bays, and estuaries.
Sandbar shark, bignose shark, and silky shark have interdorsal ridges. Finetooth shark has unmarked fins. Spinner shark, most difficult to distinguish, has fairly small first dorsal fin originating at or just behind free tips of pectoral fins, black-tipped anal fin in specimens >2.6 ft (0.8m). Bull shark has shorter snout, first dorsal fin rearward sloping; fins not usually black-tipped.
Text descriptions taken from:
Guide to Sharks, Tunas, & Billfishes
of the U.S. Atlantic and Gulf of Mexico