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Dusky Shark

Carcharhinus obscurus

Distinguishing Characteristics

Illustration of a dusky shark showing important characteristics
  • Back is bronze-gray to blue-gray, fading to a white belly
  • Snout moderately rounded, shorter than or equal to mouth width
  • Second dorsal fin free tip less than twice as long as fin height
  • First dorsal fin is sloping with its origin over the pectoral fin free tip
  • Interdorsal ridge present

Similar Species: Caribbean Reef shark, C. perezii (bluntly rounded snout); Sandbar shark, C. plumbeus (first dorsal fin starts in front of pectoral fin insertion); silky shark, C. falciformis (first dorsal fin starts behind pectoral fin free tip; longer second dorsal fin free tip)


Among the slowest growing of shark species. Maximum size is up to 12.5 feet.  Matures at approximately 20 years of age (about 8.5 feet) and is estimated to live 45+ years.


A cosmopolitan species inhabiting continental nearshore areas and offshore waters.  Adults are known to migrate great distances and avoid estuaries with low salinities.  Juveniles congregate in shallow bays and estuaries.


Feeds on other sharks, skates, rays, fishes, and variety of invertebrates including squid and starfish.


Mating occurs in the spring and after approximately 16 months of gestation, females give birth to live young in shallow bays and coastal lagoons.  Broods contain 6-14 pups.  Size at birth about 3 feet.

Additional Information

Dusky sharks have been federally protected since 1999 and harvest is prohibited from U.S. federal waters.  Since 2006, Florida has included dusky sharks on the state prohibited species list, therefore, it is unlawful to harvest, possess, land, purchase, sell or exchange this species.  Historically, this species was targeted in commercial shark fisheries mainly for their high-quality fins, flesh, skin, and liver oil.  On a global scale, their populations are considered vulnerable (ICUN). Infrequently associated with shark bites on humans.

Recreational Regulations

Image Credit: © Diane Rome Peebles