Featured Species: Caribbean Reef Shark (Carcharhinus perezi)

 

This week’s featured species is one of the more common species throughout the Caribbean Sea. The Caribbean Reef Shark (Carcharhinus perezi) is a moderately large bodied shark with a short, bluntly rounded snout and small nasal flaps (Ebert, Fowler, & Dando, 2015). The Caribbean reef shark has large, narrow pectoral fins and a comparatively small first dorsal fin with an even shorter second dorsal fin. These sharks tend to be dark gray or silver ventrally, flanked by a white stripe, before fading to a white belly (Ebert, Fowler, & Dando, 2015). Their pectoral fins, anal, and lower lobe of the caudal fin are slightly dusky in color (Compagno, 2001).

sharks swimming through a coral reef
Skerry, B. (Photographer). (n.d.). Caribbean Reef Sharks over reef [Digital Image]. Retrieved from https://ocean.si.edu/

Like many reef dwelling species, Caribbean reef sharks are generalized predators. They feed on small bony reef fishes, smaller sharks and rays,  and even soft bodies cephalopods (Tricas et al., 1997). They are one of the few species throughout the Caribbean that have been observed feeding on the invasive lionfish; though these predations do not appear to be a regular occurrence.

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Gross, S. (Photographer). (2016). Caribbean Reef Shark Eating Lionfish [Digital Image]. Retrieved from https://www.stocksy.com/

The Caribbean reef shark has a jaw that exhibits heterodonty, or having different teeth, which helps them tackle the wide variety of prey items in their diet. Their top teeth are well serrated with broad bases and narrow cusps. While the teeth in the lower jaw have much narrower bases, smaller serrations, with straight and narrow cusps (Tricas et al., 1997).

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Left: Robertson, D. R. (Photographer). (2016). C. perezi upper jaw [Digital Image]. Retrieved from https://en.wikipedia.org/ Center: Robertson, D. R. (Photographer). (2016). C. perezi jaw [Digital Image]. Retrieved from https://en.wikipedia.org/ Right: Robertson, D. R. (Photographer). (2016). C. perezi lower jaw [Digital Image]. Retrieved from https://en.wikipedia.org/

When a shark seizes its prey, it’s over in a flash! But if we were to slow down the sequence, we would see four distinct, but continuous, behaviors that the Caribbean reef shark, like many other ram feeding sharks, exhibit in less than a second (Klimley, 2013).

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Fig. 12.4. Ram feeding by the Caribbean reef shark (Klimley, 2013).
  1. The first of these phases is the Preparatory Phase. In this phase, the Caribbean reef shark opens its mouth slightly, while water passes over its gills to extract oxygen.
  2. The second phase is the Expansive Phase. In this phase, the Caribbean reef shark raises its head and the mouth drops open as the labial cartilage that attaches to the upper and lower jaws moves apart. The branchial chamber also expands.
  3. The third phase is the Compressive Phase. This phase begins when the Caribbean reef shark’s mouth is open at its widest. The lower jaw begins to elevate and the upper jaw protrudes forward and down. The head lowers. By the end of this phase, the Caribbean reef shark has either seized its prey between its teeth or has drawn its prey down into its mouth, when successful of course.
  4. The final phase is the Recovery Phase. In this phase, the Caribbean reef shark’s upper jaw has retracted and the rest of the jaw has returned to the original resting position (Klimley, 2013).

 

Shark wildlife tourism has been expanding globally for the last several decades (Cisneros-Montemayor, Barnes-Mauthe, Al-Abdulrazzak, Navarro-Holm, & Sumaila, 2013). In 2013, shark watching activities grossed $215 million (USD) in reporting countries! It is estimated that within 20 years shark ecotourism will gross $785 million (USD) annually (Cisneros-Montemayor, et al., 2013)! Throughout the Caribbean, many shark species, including Caribbean reef sharks, are regularly fed as a part of shark diving tours for the benefit of tourists (Parker, 2008). Some biologists have expressed concerns that shark feeding practices could lead to sharks associating humans with food, potentially leading to an increase in negative shark-human encounters. There is evidence to suggest that sharks participating in these feedings are capable of associating human activity in the water with food. Observational studies have shown that sharks participating in feedings learn the routine, and will approach the dive site at the sound of the approaching boat (Parker, 2008). On the other hand, when ecotourism is executed correctly, can have long reaching positive benefits for both sharks and local community. The shark tourism industry generates substantial revenues that can manage and protect sharks and their habitats, and also raises awareness for the need for conservation of both habitat and species (De Los Monteros, 2002; Goodwin, 1996).

Fintastic Films [Vidoegrapher]. (2018). Caribbean Reef Shark Feeding Frenzy [Video Clip]. Retrieved from https://www.youtube.com/

The Caribbean reef shark is one of the most common reef sharks throughout the Caribbean Sea, and yet they are categorized as a Near Threatened species by the International Union for the Conservation of Nature (IUCN). Current tag and recapture studies suggest that their populations are declining throughout their range (Graham, & Burgess, 2004; Pikitch, Chapman, Babcock, & Shivji, 2005). Caribbean reef sharks are taken as bycatch in artisanal and commercial longline and gillnet fisheries and faces particularly heavy fishing pressures in regions like Brazil (Amorim, Arfelli, & Fagundes, 1998; Rosa, Mancini, Caldas, & Graham, 2006). When the Caribbean reef shark is taken by fisheries, they are utilized for human consumption in a number of ways. Their liver is utilized for its oil; a gallon of shark liver oil can fetch $40 to $50 (USD).  Their meat is only occasionally used as it is not easily marketed. Their jaws can also be sold for $50 to $60 (USD) depending on the size. Their fins are valuable in the fin trade, fetching $45 to $55 (USD) per 1 lb (0.45 kg) (Caldas Aristizábal, 2017). Luckily, the Caribbean reef shark is protected in several marine protected areas (MPA’s) throughout its home range. Enforcement of fishing regulations within MPA’s remains a tough challenge, if not the toughest challenge. Illegal fishing does continue with MPA’s, and sharks are known to be taken within these regions; however, the numbers are significantly lower than unprotected regions (Rosa, Macini, Caldas, & Graham, 2006).

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Zenato, C. (Photographer). (2019). Next time someone tells me that hooks do not affect sharks I would like to invite them on these dives and see how these animals are actually extremely affected by them. This hook is way deep and I am not sure I will be able to reach that far down and remove it without any risk [Digital Image]. Retrieved from https://www.instagram.com/

Shark Stats

Authority: Poey, 1876

Family: Carcharhinidae, 59+ species

Length: 9,67 feet (2.95 m)

Weight: Up to 150 lbs (70 kg)

Habitat: Commonly found along coral reefs throughout the Caribbean Sea

Depth: 100 feet (30 m) (+/-)

Reproduction: Placental Viviparous

Gestation: Approximately 1 year

Litter Range: 3 – 6 pups

Home Range: Subtropics and tropics of the Caribbean from as far North as the United States to as far south as Brazil, and ranging from the Bahamas in the east to Belize in the West

Diet: Small bony reef fishes, other sharks, rays, and cephalopods

IUCN Status: Near Threatened

(Tricas, et al., 1997; Rosa, Macini, Caldas, & Graham, 2006; Ebert, Fowler, & Dando, 2015)

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. Proceeds benefit shark research and conservation with a donation to Project AWARE!

Thanks so much for checking out the Caribbean Reef Shark! If you missed last week’s featured species, please be sure to check out the bizarre Birdbeak Dogfish! 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. Also connect with me on Instagram and Facebook for even more elasmo fun!

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!

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Featured Image Source

Stewart, R. (Photographer). (2015). Caribbean reef shark, Freeport, Bahamas [Digital Image]. Retrieved from https://www.sharkwater.com/wp-content/uploads/2015/02/pr17.jpg

 

Literature Cited

Amorim, A. F., Arfelli, C. A., & Fagundes, L. (1998). Pelagic elasmobranchs caught by longliners off southern Brazil during 1974–97: an overview. Marine and Freshwater Research49(7), 621-632.

Caldas Aristizábal, JP (2017). Ichthyofauna companion of the industrial fishing with horizontal longline in the banks and basses of the north zone of the archipelago of San Andrés, Providencia and Santa Catalina, Colombian Caribbean (Bachelor’s thesis, University of Bogotá Jorge Tadeo Lozano).

Cisneros-Montemayor, A. M., Barnes-Mauthe, M., Al-Abdulrazzak, D., Navarro-Holm, E., & Sumaila, U. R. (2013). Global economic value of shark ecotourism: implications for conservation. Oryx, 47(3), 381–388.

Compagno, L. J. (2001). Sharks of the world. An annotated and illustrated catalogue of shark species known to date, vol 2. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). FAO species catalogue for fishery purposes1, viii+-1.

De Los Monteros, R. L. E. (2002). Evaluating ecotourism in natural protected areas of La Paz Bay, Baja Clifornia Sur, Mexico: ecotourism or nature-based tourism? Biodiversity & Conservation, 11(9), 1539–1550.

Ebert, D. A., Fowler, S. L., & Dando, M. (2015). Sharks of the world: a fully illustrated guide. Wild Nature Press.

Goodwin, H. (1996). In pursuit of ecotourism. Biodiversity and Conservation, 5(October 1995), 277–291.

Graham, R. T., & Burgess, G. (2004). Abundance and Diversity of Reef-Associated Sharks at the Gladden Spit Marine Reserve, Belize-Preliminary Results.

Klimley, A. P. (2013). The biology of sharks and rays. University of Chicago Press.

Parker, S. (2008). The encyclopedia of sharks (2nd ed.). Buffalo, NY: Firefly Books Ltd.

Pikitch, E. K., Chapman, D. D., Babcock, E. A., & Shivji, M. S. (2005). Habitat use and demographic population structure of elasmobranchs at a Caribbean atoll (Glover’s Reef, Belize). Marine Ecology Progress Series302, 187-197.

Rosa, R.S., Mancini, P., Caldas, J.P. & Graham, R.T. (2006). Carcharhinus pereziThe IUCN Red List of Threatened Species. Retrieved from https://www.iucnredlist.org/species/60217/12323052

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.

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Featured Species: Sicklefin Weasel Shark (Hemigaleus microstoma)

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Featured Species: Birdbeak Dogfish (Deania calcea)

 

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