This week’s featured species is a relatively common species found on coral reefs and shallow lagoons of the Indian and Pacific oceans. The Blacktip reef shark (Carcharhinus melanopterus) is a medium sized shark, typically reaching up to 6.5 feet (2.0 m) in length. They have a slender body, with a short, broad, rounded snout (Ebert, Fowler, & Dando, 2015). To match their slender bodies, they have relatively narrow pectoral fins and their dorsal fins have smooth, rounded tips. Characteristic of the blacktip reef shark are their black tipped fins, highlighted by a band of white around the caudal fin and dorsal fins. They also have a distinctive pale band that runs along either side of their bodies beginning at their pectoral fins (Ebert, Fowler, & Dando, 2015).
Often times, the blacktip reef shark can be mistaken for the blacktip shark (Carcharhinus limbatus). Both are members of the Carcharhinidae family, however the blacktip shark is a larger bodied shark than the blacktip reef shark. While both species do have characteristic black caudual and pectoral fin tips, the blacktip reef shark has the white band that highlights these band marks, as well as the black dorsal tips. The blacktip shark lacks the dorsal fin markings (Tricas, et al., 1997). Both sharks exhibit counter-shading camouflage, where the top of the shark shaded grey or brown grey, and the belly of the shark is white. This helps the shark blend with the surrounding water column when looking down on the shark from above, or looking up at the shark from underneath (Parker, 2008). The blacktip reef shark is only found in the warm temperate and tropical waters of the Indian and Pacific Oceans, and in the Eastern Mediterranean via the Suez Canal. The blacktip shark has a much wider home range. It can be found worldwide in warm temperate and tropical waters in many of the same reef and lagoon habitats as the blacktip reef shark (Burgess, & Branstetter, 2009). Due to all of their similarities and overlapping habitat preferences, these two species can cause some confusion when trying to identify species.
The blacktip reef shark is a nimble reef predator. Their diet consisted primarily of teleost reef fishes, though examinations of their stomach contents have also shown that they are capable of eating crustaceans, cephalopods, molluscs, and even other elasmobranchs (Lyle, 1987; Last & Stevens, 2009). Their teeth are ideally designed to handle their fish heavy diet. The teeth in their upper jaws have a wide base that quickly become narrow, and they are strongly serrated for cutting through their prey. The teeth in their lower jaws are much more narrow and more finely serrated than their upper jaw. These help with piercing and holding their prey (Tricas, et al., 1997).
And these guys mean business when they are hunting! It is frequently reported that blacktip reef sharks will hunt in waters as shallow as 1 foot (30 cm) (Tricas, et al., 1997). In water this shallow their dorsal fins will breach the water as they chase after their prey! Forgive the audio of this video! But it is the perfect example of how close to shore these sharks are willing to go for a meal!
Joe Edmondson (Videographer). (2012 Feb). Blacktip Reef Sharks Hunting – Maldives [Video Clip]. Retrieved from https://www.youtube.com/
Despite being a relatively common species in the Indo-Pacific, the blacktip reef shark is currently listed as Near Threatened by the International Union for Conservation of Nature (IUCN). The major reason for this is due to the overwhelming fishing pressures in this region over the last several decades and it still continues today. While the blacktip reef shark is not directly targeted by these fisheries, they are regularly caught by inshore fisheries in India and Thailand, as well as in gillnets in Australia (Compagno, 2001; Last & Stevens, 2009). Sadly, these sharks have little commercial use, so when they are caught, they bring little to no value. They are sometimes use for their liver oil and rarely the meat is consumed, but mostly they are bycatch in commercial fisheries that is ultimately wasteful (Last & Stevens, 2009). Like many species of elasmobranch, the blacktip reef shark has low fecundity, only having 2 to 4 pups at a time. They also have long gestation periods of up to 16 months and reproduction cycles of 2 years. They also take several years to reach sexual maturity (Stevens, 2001). Due to the nature of their life history characteristics and the current pressures from fisheries industries in the Indo-Pacific, the blacktip reef shark is a threatened species and should continued to be monitored closely for signs of population decline.
Prof. Dr. Sc. Norman Ali Bassam Ali Taher Khalaf (Videographer). (2017 December). Black Tip Reef Sharks at Abu Dhabi Fish Market 02.11.2017 [Video Clip]. Retrieved from https://www.youtube.com/
I’m delighted to announce a partnership with the wonderfully talented Julius Csotonyi! Julius creates stunning shark coloring sheets that are fun and educational for all ages. From time to time you’ll see Julius’ work featured right here and on my other social media platforms! You are welcomed to download these beautiful sheets and enjoy them with family and friends.
Authority: Quoy & Gaimard, 1824
Family: Carcharhinidae; 59+ species
Length: Up to 6.5 feet (2 m)
Weight: Up to 40 lbs (18.1 kg)
Habitat: Shallow coral reefs
Depth: Surface to 262 feet (80 m)
Reproduction: Placental Viviparous
Gestation: Likely 10-11 months, potentially as long as 16 months
Litter Range: 2 – 4 pups
Home Range: Warm temperate waters and tropical waters of the Western Pacific, Indian Ocean, and Eastern Mediterranean via the Suez Canal
Diet: Teleost fishes, crustaceans, cephalopods, molluscs, and the rare small elasmobranch
IUCN Status: Near Threatened
(Lyle, 1987; Stevens, 2001; Heupel, 2009; Last & Stevens, 2009; Ebert, Fowler, & Dando, 2015)
Thanks so much for checking out the Blacktip Reef Shark! If you missed last week’s featured species, please be sure to check out the shocking Great Torpedo Ray! If there is a species of elasmobranch you’d love to know more about, leave me a comment or send me a message! I would love to do a feature on your favorite species. So connect with me on Instagram and Facebook for even more elasmo fun!
The new Ocean For Sharks Shop is open! There’s handmade ocean inspired plush animals, canvas paintings, and of course my children’s book, Winifred the Wondrous Whale Shark, available in print and PDF. Be sure to stop by. Remember proceeds benefit shark research and conservation with a donation to Project AWARE!
Conservation legislation needs public support in order to become law and help protect the environment and wildlife. Tell your representatives that you care about environmental and wildlife conservation. It only takes a moment to make a change that will last a lifetime. Until next time finactics!
Featured Image Source
Monterey Bay Aquarium (Photographer). (n.d.). Blacktip Reef Shark [Digital Image]. Retrieved from https://www.montereybayaquarium.org/
Burgess, H. G. & Branstetter, S. (2009). Carcharhinus limbatus. The IUCN Red List of Threatened Species. Retrieved from https://www.iucnredlist.org/species/3851/10124862
Compagno, L. J. (2001). Sharks of the world: an annotated and illustrated catalogue of shark species known to date (Vol. 1). Food & Agriculture Org..
Ebert, D. A., Fowler, S. L., & Dando, M. (2015). Sharks of the world: a fully illustrated guide. Wild Nature Press.
Heupel, M. (2009). Carcharhinus melanopterus. The IUCN Red List of Threatened Species. Retrieved from https://www.iucnredlist.org/species/39375/10219032
Last, P. R., & Stevens, J. D. (2009). Sharks and rays of Australia.
Lyle, J. M. (1987). Observations on the biology of Carcharhinus cautus (Whitley), C. melanopterus (Quoy & Gaimard) and C. fitzroyensis (Whitley) from northern Australia. Marine and Freshwater Research, 38(6), 701-710.
Parker, S. (2008). The encyclopedia of sharks (2nd ed.). Buffalo, NY: Firefly Books Ltd.
Stevens, J. D. (2001). Life-history and ecology of sharks at Aldabra Atoll, Indian Ocean. Proc. R. Soc. Lond. B, 222(1226), 79-106.
Tricas, T. C., Deacon, K., Last, P., McCosker, J. E., Walker, T. I., & Taylor, L. (1997). The Nature Company Guides: Sharks and Rays. (L. Taylor, Ed.). Hong Kong: The Nature Company, Time Life Books.