The Caribbean reef shark (''Carcharhinus perezi'') is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
of
requiem shark, belonging to the
family Carcharhinidae. It is found in the tropical waters of the western
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
from
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...
to
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
, and is the most commonly encountered reef shark in the
Caribbean Sea. With a robust, streamlined body typical of the requiem sharks, this species is difficult to tell apart from other large members of its family such as the
dusky shark (''C. obscurus'') and the
silky shark
The silky shark (''Carcharhinus falciformis''), also known by numerous names such as blackspot shark, gray whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the ...
(''C. falciformis''). Distinguishing characteristics include dusky-colored fins without prominent markings, a short free rear tip on the second
dorsal fin, and tooth shape and number.
Measuring up to long, the Caribbean reef shark is one of the largest
apex predators in the reef
ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...
, feeding on a variety of fishes and
cephalopods. They have been documented resting motionless on the sea bottom or inside caves, unusual behavior for an active-swimming shark. If threatened, it may perform a
threat display in which it frequently changes direction and dips its
pectoral fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...
s. Like other requiem sharks, it is
viviparous with females giving birth to 4–6 young every other year. Caribbean reef sharks are of some importance to
fisheries as a source of meat,
leather,
liver oil, and
fishmeal
Fish meal is a commercial product made from whole wild-caught fish, bycatch and fish by-products to feed farm animals, e.g., pigs, poultry, and farmed fish.R. D. Miles and F. A. Chapman.FA122: The Benefits of Fish Meal in Aquaculture DietsFisheri ...
, but recently they have become more valuable as an
ecotourist attraction. In the
Bahamas
The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the a ...
and elsewhere, bait is used to attract them to groups of divers in controversial "shark feedings". This species is responsible for a small number of
attacks on humans. The shark attacks usually happen in spring and summer.
Taxonomy and phylogeny
The Caribbean reef shark was originally described as ''Platypodon perezi'' by
Felipe Poey in 1876, in the
scientific journal ''Anales de la Sociedad Española de Historia Natural''. The
type specimens were six individuals caught off the coast of
Cuba
Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribb ...
. The
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''Platypodon'' was
synonymized with ''Carcharhinus'' by later authors.
Based on
morphological similarities,
Jack Garrick
John Andrew Frank "Jack" Garrick (1928 – August 30, 2018) was a New Zealand ichthyologist. He specialized in elasmobranchs and published many books and articles about shark and ray biology. In 1982, he published a thorough taxonomy on sharks of ...
in 1982 grouped this species with the
bignose shark (''C. altimus'') and the
sandbar shark (''C. plumbeus''), while
Leonard Compagno in 1988 placed it as the
sister species of the
grey reef shark (''C. amblyrhynchos''). A
phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups ...
analysis based on
allozyme data, published by Gavin Naylor in 1992, indicated that the Caribbean reef shark is the sister
taxon to a
clade formed by the
Galapagos shark (''C. galapagensis''),
dusky shark (''C. obscurus''),
oceanic whitetip shark (''C. longimanus''), and the
blue shark (''Prionace glauca''). However, more work is required to fully resolve the interrelationships within ''Carcharhinus''.
Distribution and habitat
The Caribbean reef shark occurs throughout the tropical western
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
, from
North Carolina
North Carolina () is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. The state is the List of U.S. states and territories by area, 28th largest and List of states and territories of the United ...
in the north to
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
in the south, including
Bermuda, the northern
Gulf of Mexico, and the
Caribbean Sea. However, it is extremely rare north of the
Florida Keys. It prefers shallow waters on or around
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of Colony (biology), colonies of coral polyp (zoology), polyps held together by calcium carbonate. Most coral reefs are built from stony corals, wh ...
s, and is commonly found near the drop-offs at the reefs' outer edges.
[Scharfer, A]
Biological Profiles: Caribbean Reef Shark
. ''Florida Museum of Natural History Ichthyology Department''. Retrieved on February 14, 2009. This shark is most common in water shallower than , but has been known to dive to .
Description
A heavy-bodied shark with a "typical" streamlined shape, the Caribbean reef shark is difficult to distinguish from other large requiem shark species. It usually measures long; the maximum recorded length is and the maximum reported weight is .
The coloration is dark gray or gray-brown above and white or white-yellow below, with an inconspicuous white band on the flanks. The fins are not prominently marked, and the undersides of the paired fins, the
anal fin, and the lower lobe of the
caudal fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...
are dusky.
The snout is rather short, broad, and rounded, without prominent flaps of skin beside the nostrils. The eyes are large and circular, with
nictitating membranes (protective third eyelids). There are 11–13 tooth rows in either half of both jaws. The teeth have broad bases, serrated edges, and narrow cusps; the front 2–4 teeth on each side are erect and the others increasingly oblique. The five pairs of
gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In co ...
s are moderately long, with the third gill slit over the origin of the
pectoral fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...
s.
The first
dorsal fin is high and falcate (sickle-shaped). There is a low interdorsal ridge running behind it to the second dorsal fin, which is relatively large with a short free rear tip. The origin of the first dorsal fin lies over or slightly forward of the free rear tips of the pectoral fins, and that of the second dorsal fin lies over or slightly forward of the
anal fin. The pectoral fins are long and narrow, tapering to a point.
The
dermal denticles are closely spaced and overlapping, each with five (sometimes seven in large individuals) horizontal low ridges leading to marginal teeth.
Carcharhinus perezii jaws.jpg, Jaws
Carcharhinus perezii upper teeth.jpg, Upper teeth
Carcharhinus perezii lower teeth.jpg, Lower teeth
Biology and ecology
Despite its abundance in certain areas, the Caribbean reef shark is one of the least-studied large requiem sharks. They are believed to play a major role in shaping Caribbean reef communities. These sharks are more active at night, with no evidence of seasonal changes in activity or
migration. Juveniles tend to remain in a localized area throughout the year, while adults range over a wider area.
Caribbean reef sharks are sometimes seen resting motionless on the sea floor or inside caves; it is the first active shark species in which such a behavior was reported. In 1975,
Eugenie Clark investigated the famed "sleeping sharks" inside the caves at
Isla Mujeres off the
Yucatan Peninsula, and determined that the sharks were not actually asleep as their eyes would follow divers. Clark speculated that freshwater upwellings inside the caves might loosen parasites on the sharks and produce an enjoyable "narcotic" effect.
[Martin, R.A]
Caribbean Reef Shark
''ReefQuest Centre for Shark Research''. Retrieved on February 14, 2009. If threatened, Caribbean reef sharks sometimes perform a
threat display, in which they swim in a short, jerky fashion with frequent changes in direction and repeated, brief (1–1.2 second duration) drops of the pectoral fins. This display is less pronounced than the better-known display of the
grey reef shark (''C. amblyrhynchos'').
Juvenile Caribbean reef sharks are preyed upon by larger sharks such as the
tiger shark (''Galeocerdo cuvier'') and the
bull shark (''C. leucas''). Few
parasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson h ...
s are known for this species; one is a dark variegated
leech often seen trailing from its first dorsal fin.
Off northern Brazil, juveniles seek out cleaning stations occupied by
yellownose gobies (''Elacatinus randalli''), which clean the sharks of parasites while they lie still on the bottom.
Horse-eye jacks (''Caranx latus'') and
bar jack
The bar jack (''Caranx ruber''), also known as the carbonero, red jack, blue-striped cavalla or passing jack, is a common species of inshore marine fish classified in the jack family, Carangidae. The bar jack is distributed through the western ...
s (''Carangoides ruber'') routinely
school
A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes co ...
around Caribbean reef sharks.
Feeding
The Caribbean reef shark feeds on a wide variety of reef-dwelling
bony fishes and cephalopods, as well as some
elasmobranchs such as
eagle rays (''Aetobatus narinari'') and
yellow stingrays (''Urobatis jamaicensis'').
It is attracted to low-frequency
sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by ...
s, which are indicative of struggling fish.
In one observation of a long male Caribbean reef shark hunting a
yellowtail snapper
The yellowtail snapper (''Ocyurus chrysurus'') is an abundant species of snapper native to the western Atlantic Ocean including the Gulf of Mexico and the Caribbean Sea. Although they have been found as far north as Massachusetts, their normal ...
(''Lutjanus crysurus''), the shark languidly circled and made several seemingly "half-hearted" turns towards its prey, before suddenly accelerating and swinging its head sideways to capture the snapper at the corner of its jaws.
Young sharks feed on small fishes, shrimps, and crabs.
Caribbean reef sharks are capable of everting their
stomachs, which likely serves to cleanse indigestible particles, parasites, and mucus from the stomach lining.
Life history
Reproduction is
viviparous; once the developing
embryos exhaust their supply of
yolk
Among animals which produce eggs, the yolk (; also known as the vitellus) is the nutrient-bearing portion of the egg whose primary function is to supply food for the development of the embryo. Some types of egg contain no yolk, for example ...
, the
yolk sac
The yolk sac is a membranous wikt:sac, sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac' ...
develops into a
placental connection through which they receive nourishment from their mother. Mating is apparently an aggressive affair, as females are often found with biting scars and wounds on their sides.
At the Fernando de Noronha Archipelago and Atol das Rocas off Brazil, parturition takes place at the end of the
dry season
The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The ...
from February to April, while at other locations in the Southern Hemisphere, females give birth during the
Amazon
Amazon most often refers to:
* Amazons, a tribe of female warriors in Greek mythology
* Amazon rainforest, a rainforest covering most of the Amazon basin
* Amazon River, in South America
* Amazon (company), an American multinational technolog ...
summer in November and December.
The average litter size is four to six, with a
gestation period of one year. Females become pregnant every other year.
The newborns measure no more than long; males
mature sexually at long and females at .
Human interactions
Normally shy or indifferent to the presence of divers, the Caribbean reef shark has been known to become aggressive in the presence of food and grows sufficiently large to be considered potentially dangerous.
As of 2008, the
International Shark Attack File lists 27 attacks attributable to this species, 4 of them unprovoked, and none fatal, though a fatal attack on the island of St. Martin/St. Maarten in 2020 is being blamed on the species.
This species is taken by
commercial and
artisanal
An artisan (from french: artisan, it, artigiano) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art, ...
longline and
gillnet fisheries throughout its range. It is valued for meat, leather,
liver oil and
fishmeal
Fish meal is a commercial product made from whole wild-caught fish, bycatch and fish by-products to feed farm animals, e.g., pigs, poultry, and farmed fish.R. D. Miles and F. A. Chapman.FA122: The Benefits of Fish Meal in Aquaculture DietsFisheri ...
. The Caribbean reef shark is the most common shark landed in
Colombia (accounting for 39% of the longline catch by occurrence), where it is utilized for its fins, oil and jaws (sold for ornamental purposes). In Belize, this species is mainly caught as
bycatch on hook-and-line intended for
grouper
Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes.
Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" ...
s and
snappers; the fins are sold to the lucrative Asian market and the meat sold in Belize,
Mexico
Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
, and
Guatemala to make "panades", a
tortilla-like confection. A dedicated shark fishery operated in Belize from the mid-1900s to the early 1990s, until catches of all species saw dramatic declines.
The flesh of this species may contain high levels of
methylmercury and other
heavy metals.
Shark feeding
A profitable ecotourism industry has arisen around this species involving organized "shark feeds", in which groups of reef sharks are attracted to divers using bait. Some US$6,000,000 is spent annually on shark viewing in the
Bahamas
The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the a ...
, where at some sites a single living Caribbean reef shark has a value between US$13,000 and US$40,000 (compared to a one-time value of US$50–60 for a dead shark).
This practice has drawn controversy, as opponents argue that the sharks may learn to associate humans with food, increasing the chances of a shark attack, and that the removal of reef fishes for bait may damage the local ecosystem. Conversely, proponents maintain that shark feeds contribute to conservation by incentivizing the protection of sharks and educating people about them. Thus far, there has been little evidence that shark feeds have increased the risk of attack in the surrounding area.
[Murch, A]
Shark Feeding
''Elasmodiver.com''. Retrieved on February 14, 2009 Shark feeding has been outlawed off the coast of Florida, but continues at other locations in the Caribbean.
Conservation
The
International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
(IUCN) has assessed the Caribbean reef shark as
Endangered; its population has declined off Belize and Cuba from
overfishing and exploitation continues in other regions. They are also threatened by the degradation and destruction of their coral reef habitat.
Commercial fishing for this species is prohibited in
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
waters.
They are protected in the Bahamas due to their significance to ecotourism, as well as in a number of
Marine Protected Area
Marine protected areas (MPA) are protected areas of seas, oceans, estuaries or in the US, the Great Lakes. These marine areas can come in many forms ranging from wildlife refuges to research facilities. MPAs restrict human activity for a con ...
s (MPAs) off Brazil and elsewhere. However, enforcement against
illegal fishing
Illegal, unreported and unregulated fishing (IUU) is an issue around the world. Fishing industry observers believe IUU occurs in most fisheries, and accounts for up to 30% of total catches in some important fisheries.
Illegal fishing takes p ...
is lacking in some of these reserves, and many areas in which this species is abundant are not protected.
References
External links
*
* Video o
Caribbean Reef Shark- Video taken in Belize off Ambergris Caye.
{{Good article
Caribbean reef shark
Fish of the Caribbean
Fish of the Dominican Republic
Fish of Brazil
Caribbean reef shark
Fish of Cuba