Sharks of Onslow County Logo
Sharks of Onslow County
Bull Shark

Taxonomy & Biology

Taxonomy

Common Name(s): Bull shark, shovelnose, square-nose shark, river shark, slipway grey shark, cub shark.

Scientific Name: Carcharhinus leucas

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: leucas

Biology

Population

Bull sharks prefer shallow coastal waters less than 100 feet deep (Curtis, French & Naylor, 2025). They commonly enter estuaries, sounds, harbors, lagoons, and river mouths. They can spend long periods of time in freshwater systems. They can also tolerate very high salinity, up to 53 parts per thousand (ppt).

Nursery populations of bull sharks were rarely captured or detected by the NC Division of Marine Fisheries in the Pamlico Sound in North Carolina between 1965-2011. However, between 2011 to 2016, they were present. Their presence is linked to early warming summer temperatures and late summer salinities (Bangley et al., 2018).

Nursery habitats are associated in areas with limited access to he ocean and highly variable salinity that correlate to North Carolina's barrier islands and narrow inlets. The historical rarity of bull sharks in the area has been attributed to temperature preferences or philopatry - the tendency to remain or return to the area of one's birth.

They are not a targeted species for commercial fisheries, however, are often caught as bycatch of bottom longline gear (Curtis, French & Naylor, 2025).

Body Size

At maturity, between 15-20 years old, bull sharks grow to between 5-7 feet for males, and 6-7.5 feet for females (Curtis, French & Naylor, 2025). Juveniles range between 2-3 feet at birth. Their known lifespan is 25 years old.

They have a heavy body that lacks an interdorsal ridge. Their snout is very short and broadly rounded (NC Fishes, 2021). The first dorsal fin is large and triangular, and the second dorsal fin is much smaller (Curtis, French & Naylor, 2025). They have smaller eyes which suggests that their vision is not their primary sense since they tend to reside in more turbid waters.

They have countershading which means they are pale to dark grey above and fades to a pale, cream color on their underside. Juvenile species have dark-tipped fins that fade into a more dusky color.

Feeding & Diet

Bull sharks typically feed on bony fishes, like mullet, tarpon, menhaden, gar, mackerel, snapper, and other schooling fishes (Curtis, French & Naylor, 2025). They will also consume other sharks and stingrays.

Bull sharks cruise along the seafloor and may appear sluggish. However, they are known to do very quick bursts to catch more agile prey. They can move up to 11 mph over short distances.

Position in the Food Web

Bull sharks are considered apex predators with very few predators (Curtis, French & Naylor, 2025). As jureniles, bull sharks can be prey of tiger sharks, sandbar sharks, and other bull sharks.

Bull sharks often have parasites. Copepods (Pandarus sinatus and Perissopus dentatus) attach to their body surface in the axil range and pectoral and pelvic fins.

Humans pose the largest threat to bull sharks from fishing, habitat degradation, and as an international target for fins.

Reproduction

Females reach reproduction age at approximately 18 years old and between 6-7.5 feet long (Curtis, French & Naylor, 2025). Males reach reproduction age between 14-15 years old and between 5.1 to 7.41 feet long.

Bull sharks bear live young with between 1-13 pups per litter. Developing pups are nourished by a yolk-sac placenta. The gestation period is between 10-11 months.

Mating and birthing occurs year-round in their warmest parts of their range. But, in places like the Gulf of Mexico, mating occurs in the summer months, with birth in April-June. Females will often display mating scars on their flanks. Common nurseries are in coastal lagoons, low-salinity estuaries, or river mouths.

Natural Mortality

Bull sharks known lifespan is greater than 25 years old.

Biodiversity

Adult bull sharks tend to migrate long distances from New Jersey to North Carolina (Bangley, 2018). Juveniles are more selective with their environment and spend most of their time in brackish estuarine water. They have a significant relationship to temperature and salinty. Since 2012, bull shark nurseries in the North Carolina have become a preference over Florida.

Demographics

Bull sharks can be found in both saltwater and freshwater, however, they are most connonly found in marine and estuarine environments. They occur in tropical and subtropical waters, as well as in river systems and freshwater lakes around the world (Curtis, French & Naylor, 2025).

Migratory Pattern

Bull sharks migrate north along the Atlantic coastline during the summer. They can migrate as far north as Massachusetts, and return to tropical climates and warmer waters when sea temperatures cool (Curtis, French & Naylor, 2025).

Juveniles are born between May and August. They show a strong preference to remain in an area until maturation and return to breed and give birth. It is believed that they leave the Pamlico Sound area between October and April when water temperatures drop below 22 degrees Celcius and mean salinity drops below 9 ppt (Bangley et al., 2018).

Ecological Relationships

Tolerance to very high salinity to freshwater/low-salinity environments makes the bull shark very adaptable to many environments. They prefer higher temperature thresholds and shallow waters. They tend to return to the place of their birth to breed and give birth, however, this is dependent on salinity and water temperatures. This makes this species susceptible to short-term, localized changes in weather and long-term climate change impacts.

Danger to Humans

Bull sharks are considered aggressive and harmful to humans. It's large size, proximity to human populations, and abundance in freshwater and/or low salinity environments make this shark a potential threat (Curtis, French & Naylor, 2025).

It has been reported that nine negative encounters with humans occurred in North Carolina between 1990 and 2011, with eight surviving (Schwartz, 2012).Attacks occurred in water temperatures between 30-31 degrees Celcius in July and August.

This is the shark that the book and movie "Jaws" is based upon from its attacks in 1916 in New Jersey (Curtis, French & Naylor, 2025).

Fishing Regulations

As of June 2025, in North Carolina, bull sharks are regulated under the Large Coastal Sharks restrictions. Minimum size for recreational anglers are 54 inches(Rawls, 2024). Only one (1) large coastal shark on the allowable species list is allowed per vessel OR per person (for shore anglers). There are gear and natural bait requirements. The head, tail, and all fins must remain intact, with no filleting, until they are landed at the dock or on shore. 

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. (2018, April 16). Is a changing environment bringing baby bull sharks to North Carolina? Southern Fried Science. https://www.southernfriedscience.com/is-a-changing-environment-bringing-baby-bull-sharks-to-north-carolina/

Bangley, C. W., Paramore, L., Shiffman, D. S., & Rulifson, R. A. (2018). Increased abundance and nursery habitat use of the bull shark (Carcharhinus leucas) in response to a changing environment in a warm-temperate Estuary. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-24510-z

Curtis, T. Q., French, L., & Naylor, G. (2025, February 3). Bull shark. Florida Museum - Discover Fishes. https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/bull-shark/

IUCN. (2022). Bull shark. IUCN Red List of Threatened Species. Retrieved November 8, 2022, from https://www.iucnredlist.org/species/39372/2910670

NC Fishes. (2021, February 27). Carcharhinus leucas. NCFishes.com. https://ncfishes.com/marine-fishes-of-north-carolina/carcharhinus-leucas/

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

Schwartz, F. J. (2012). Bull sharks in North Carolina. Journal of the North Carolina Academy of Science, 128(3-4), 88-91. https://doi.org/10.7572/2167-5880-128.3.88
© 2024 Sharks of onslow county.