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Sharks of Onslow County
Dusky Shark

Taxonomy & Biology

Taxonomy

Common Name(s): Dusky shark, black whaler, common whaler

Scientific Name: Carcharhinus obscurus

Classification

  • Kingdom:  Animalia
  • Subkingdom: Bilateria
  • Infrakingdom: Deuterostomia
  • Phylum: Chordata
  • Subphylum: Vertebrata
  • Infraphylum: Gnathostomata
  • Class: Chondrichthyes
  • Subclass: Elasmobranchii
  • Superorder: Euselachii
  • Order: Carcharhiniformes
  • Family: Carcharhinidae
  • Genus: Carcharhinus
  • Species: obscurus

Biology

Population

Dusky sharks are a wide ranging coastal and pelagic shark species. They prefer temperate and tropical waters of temperatures between 7.6 to 30.2 degrees Celcius (Corrigan, Naylor & Knickle, 2025; Kroetz, Gulak & Carlson, 2021). They occur along shallow inshore waters to the outer continental shelf. They have been observed in surface waters to depths greater than 300 meters.

Dusky sharks are slow growing, late maturation and have small litters that make them very vulnerable to exploitation. Age at maturity varies with location but is typically between 16-23 years old for males and 16-22 years old for females.

Body Size

The maximum size for dusky sharks is 11.8 feet. Size at birth ranges from 33 to 39 inches.

Dusky sharks are a requiem shark. They have low rounded dorsal fins, large falcate pectoral fins, a low interdorsal ridge,  nose, dark grey coloration, and a front dorsal fin that originates slightly before the free tips of their pectoral fins (Corrigan, Naylor & Knickle, 2025). They are counter shaded with bluish gray above and a white underside. They can often be confused for other sharks such as the silky shark (Carcharhinus falciformis) and sandbar shark (Carcharhinus plumbeus).

Feeding & Diet

Their prey consists mainly of bony and cartilginous fishes, crustaceons, and cephalopods.

Position in the Food Web

Dusky sharks are a large apex predator that is considered a generalist predator. They eat a variety of prey that includes bony and cartilginous fishes, as well as invertebrates. They help to maintain the ecosystem balance by controlling species populations beneath it in the food web.

Reproduction

Dusky sharks are live-bearing with a yolk-sac placenta. They have 3-16 pups after a 18-22 month gestation period (Corrigan, Naylor & Knickle, 2025). Size at birth ranges from 33 to 39 inches. They breed every 2-3 years and go inshore to pup.

Natural Mortality

Natural mortality is low. However, dusky shark populations declined in the 1970-1980s due to fishing pressures (Bangley, 2014). The National Marine Fisheries Service (NMFS) included these sharks on their prohibited species list and closed off areas to protect juveniles in 2000. Species recovery is projected to take about 100 years to recover from these fishing pressures.

Biodiversity

The dusky shark is a highly migratory species that is very data poor in terms of research and information (Bangley et al., 2020). Recent research has found that dusky sharks spend time along the North Carolina coast in June and from September through November. Water temperatures ranged from 16 to 25 degrees Celcius.

Demographics

Research has shown that despite protected areas along North Carolina coastlines, there is continued overlap during the Mid-Atlantic time-area closure for bottom longline fisheries between January 1 to July 31 and pelagic longline fisheries between February 1 to April 30 (Kroetz, Gulak & Carlson, 2021).

Migratory Pattern

Dusky sharks are highly migratory and coastal-pelagic inhabiting temperate, subtropical and tropical waters worldwide (Kroetz, Gulak & Carlson, 2021). They make large scale migrations that often cover thousands of kilometers per event.

They can be found in the western North Atlantic ocean from Cape Cod, Massachusetts to the Florida Keys. The North Carolina coastline is an aggregation location and nursery for this species.

They also segregate by sex and size.

Ecological Relationships

The ecological relationships of dusky sharks in North Carolina are centralized around predator-prey interactions and human activities. Juvenile dusky sharks primarily prey on ray-finned fishes from the open ocean that are found within the water column and cephalopods. As they grow larger, they consume more shark and ray species. Humans are their biggest predator through direct targeted catch or bycatch. Other sharks may consume juvenile dusky sharks. Dusky sharks utilize nearshore coastal waters as nursery habitats during the summer months. They are susceptible to fishing pressures though they are a prohibited species in commercial and recreational fisheries. As climate shifts, dusky sharks are expected to shift their distribution in search of cooler waters within their temperature tolerance.

Danger to Humans

Dusky sharks are potentially dangerous to humans. They have been implicated in human-shark interactions due to their occurrence in shallow waters and large size (Corrigan, Naylor & Knickle, 2025).

Fishing Regulations

As of June 2025, in North Carolina, dusky sharks are not allowed to be harvested as they are a protected and prohibited species for any size (Rawls, 2024). Due to their protections, they cannot be retained or landed, and, if caught, they are to be released immediately without removal from the water with minimal injury.

Please Note: The fishing regulations and information provided on this website are for general information purposes only. While we strive to ensure the accuracy and timeliness of the content, fishing laws and regulations can change frequently and vary by location. It is the responsibility of each angler to verify the current local, state, and federal fishing laws before fishing. Always consult the official website or contact the appropriate wildlife and fisheries agency for the most up-to-date rules and regulations.

We are not liable for any penalties, fines, or legal issues that may arise from the use or misuse of the information on this site.

References

Bangley, C. (2014, December 16). No endangered listing for dusky sharks (and that’s a good thing). Southern Fried Science. https://www.southernfriedscience.com/no-endangered-listing-for-dusky-sharks-and-thats-a-good-thing/

Bangley, C. W., Curtis, T. H., Secor, D. H., Latour, R. J., & Ogburn, M. B. (2020). Identifying important juvenile dusky shark habitat in the Northwest Atlantic ocean using acoustic telemetry and spatial modeling. Marine and Coastal Fisheries, 12(5), 348-363. https://doi.org/10.1002/mcf2.10120

CITES. (2022). Dusky shark. CITES Species+. Retrieved November 8, 2022, from https://www.speciesplus.net/species#/taxon_concepts/94496/legal

Corrigan, S., Naylor, G., & Knickle, C. (2025, February 3). Dusky shark. Florida Museum - Discover Fishes. https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/dusky-shark/

IUCN. (2022). Dusky shark. IUCN Red List of Threatened Species. Retrieved November 8, 2022, from https://www.iucnredlist.org/species/3852/2872747

Kroetz, A. M., Gulak, S. J., & Carlson, J. K. (2021). Horizontal and vertical movements of immature dusky sharks Carcharhinus obscurus in relation to commercial longline fisheries in the western North Atlantic Ocean. Animal Biotelemetry, 9(1). https://doi.org/10.1186/s40317-021-00258-8

Rawls, K. (2024). Proclamation Re: Shark - Commercial and Recreational - Opening Date and Harvest Restrictions (FF-2-2024). NC Division of Marine Fisheries. https://files.nc.gov/deq/documents/2023-12/FF-2-2024_Shark_Opening.pdf?VersionId=ojmPIaCH.7VqI6F8cf_GTAY1fy80NCYY#:~:text=H.,Isurus%20oxyrinchus)%20for%20recreational%20purposes
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