Dasyatis centrourarough-tailed stingray(Also: clam cracker; stingaree)

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Geographic Range

Roughtail stingrays, Dasyatis centroura, reside in tropical and temperate waters of the coastal Atlantic Ocean, ranging from the coast of Massachusetts to Brazil, the Mediterranean Sea, the Bay of Biscay, and Angola. During summer months, roughtail stingrays are more prevalent in bays, estuaries and coastal waters. From December to May, they tend to migrate to northern waters away from the coast but not beyond the continental shelf. (Mitchill, 2008)

Habitat

Roughtail stingrays usually reside in benthic environments and in marine and brackish waters. They prefer areas with sandy bottoms. In the summer, they favor bays, estuaries, and coastal waters, and in winter, they move away from the coast but not beyond the continental shelf. They generally swim at depths of 50 to 200 m, but they have been seen at depths of 274 m in the Bahamas. In the eastern Atlantic Ocean, roughtail stingrays remain near shore and are found at an average depth of 60 m, while rays in the western Atlantic are found deeper at 200 m. (MacEachran, 2004)

  • Range depth
    50 to 274 m
    164.04 to 898.95 ft

Physical Description

Male roughtail stingrays have an average width of 1.5 m while females have an average width of 1.6 m. Their disc length can be as long as 2.2 m. The body of roughtail stingrays is diamond-shaped, and a long tail trails from their backside. Their whiplike tail has many rows of venomous barbs and can grow up to 2.5 times the length of the body. Body color ranges from dark brown to an olive tone. The underside is white, while the tail is black. The outer edges of their disc bear distinctive conical tubercles. Roughtail stingrays do not have a dorsal finfold, and their snout is fairly long and angular. They can weigh as much as 300 kg. (Capape, 1993; Mitchill, 2008)

  • Sexual Dimorphism
  • female larger
  • Range mass
    300 (high) kg
    660.79 (high) lb
  • Range length
    221 (high) cm
    87.01 (high) in

Development

Rays in the family Dasyatidae, including roughtail stingrays, produce relatively few young. Stingrays in general have 1 litter a year, producing between 2 and 6 young. Embryos developing in their mother's womb receive most of their nutriment from the histotroph, a milky substance secreted by the mother’s uterine lining. Embryos absorb nutriment through their skin and spiracles. During this time, embryos absorb the yolk sack and stalk. Roughtail stingrays are born fully developed and relatively large (up to half the size of a full grown adult), increasing their chances of survival. (Capape, 1993; The IUCN Red List of Threatened Species, 2010; Weinheimer and Jonna, 2003)

Reproduction

Little is known about the natural mating behavior and mating system of roughtail stingrays. They, like other stingrays, do not form monogamous pairs, and they may be polygynous like southern sting rays (Dasyatis americana). Rays practice internal fertilization; a male inserts one of his two claspers into the female’s cloaca to deposit sperm. (Weinheimer and Jonna, 2003)

Male roughtail stingrays reach sexual maturity at a length of 130 to 150 cm and females at 140 to 160 cm. In females ready to reproduce, their left ovary is commonly more developed than the right. Roughtail stingrays generally breed in Autumn or early winter. Gestation lasts 4 months, and females usually give birth in April. Stingrays have one litter a year, producing between 2 and 6 young. Roughtail stingrays measure between 34 at 37 cm at birth. (Ribeiro-Prado and Amorim, 2008; The IUCN Red List of Threatened Species, 2010; Weinheimer and Jonna, 2003)

  • Breeding interval
    Roughtail Stingrays breed once a year.
  • Breeding season
    Roughtail Stingrays breed in Autumn or early winter.
  • Range number of offspring
    2 to 6
  • Average gestation period
    4 months

Pregnant female roughtail stingrays provide nutritional support to their developing offspring. While young are in the embryonic sac, their stomachs and intestine develop first. This helps them to digest the milky fluid (histotroph) secreted by their mother's uterus. After birth, young rays receive no further investment from their mother and are able to find food on their own. (Weinheimer and Jonna, 2003)

  • Parental Investment
  • no parental involvement
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Little information is known regarding the lifespan and longevity of roughtail stingrays. Some sharks and rays do not reach full maturity for 20 to 30 years. Large rays live about 70 years, some living for more than 100 years. (Weinheimer and Jonna, 2003)

Behavior

Rays, including roughtail stingrays, spend most of their time partially buried in sand in shallow warm waters. Rays often migrate vast distances, often in large groups. (Dulcic, et al., 2003; Weinheimer and Jonna, 2003)

Home Range

LIttle information is available regarding the home range of roughtail stingrays.

Communication and Perception

Roughtail stingrays use touch, taste, sight, hearing, and smell to perceive their enviornment. Furthermore, like other cartilaginous fish, they can detect electical waves produced by other organisms. They use this ability to find infaunal prey buried within the substrate.

Food Habits

Roughtail stingrays are opportunistic carnivores, adapting their diet to include the most available prey. Crustaceans, such as vernal crabs Liocarcinus vernalis and callianassid shrimp Upogebia affinis, are an integral part of their diet. Stomach content analyses indicate that roughtail stingrays eat cephalopods such as squid Loligo and cuttlefish Sepia latimanus. Other prey include bony fishes, like sand lance Ammodytes dubius and scup Stenotomus chrysops. Infaunal polychaete worms (Glycera dibranchiata) are also consumed. (Ribeiro-Prado and Amorim, 2008)

  • Animal Foods
  • fish
  • mollusks
  • aquatic or marine worms
  • aquatic crustaceans
  • cnidarians

Predation

Sharks are the main predators of stingrays, including rougtail stingrays. To avoid visual detection, rays conceal themselves just below the surface of muddy and sandy bottoms. Their barbed spine serves as a defense against certain predators; however, it is not always successful, as stingray spines are found in the mouths of many types of sharks. Great hammerhead sharks have a unique method of eating rays: they pin down a ray to the seafloor using their uniquely shaped head, then pivot around to bite the ray's disc. Some humans also eat roughtail stingrays. (Grey, et al., 2006)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Rays, such as roughtail stingrays, are avid hunters of benthic mollusks, fish, crustaceans and worms, and they may help regulate infaunal benthic community structure. Rays are also prey for sharks, such as great hammerhead sharks. (Chisholm, et al., 2004)

Economic Importance for Humans: Positive

Roughtail stingrays are commonly eaten by Australian Aborigines. The Aborigines use stingray spines to make spears tips, daggers, and whips. Rays are also consumed in Europe and Asia, and the fins of some rays are harvested in Asia for traditional medicinal purposes. (Weinheimer and Jonna, 2003)

Economic Importance for Humans: Negative

Roughtail stingrays have an excruciating venomous sting, which serves as their primary defense if stepped on or threatened. In some cases, their sting has been fatal to humans. Although rays are more commonly found in water depths of 50 to 200 m, they occasionally travel to shallower waters, posing a threat to humans. (Mitchill, 2008; The IUCN Red List of Threatened Species, 2010)

  • Negative Impacts
  • injures humans

Conservation Status

Although roughtail stingrays are not considered threatened, their large size and low fecundity make them vulnerable to population decreases. They are sometimes taken as bycatch or are accidentally caught through trawl fishing, artisanal fisheries and other fishing practices. (The IUCN Red List of Threatened Species, 2010)

Contributors

Eric Brown (author), San Diego Mesa College, Jared Pasquarella (author), San Diego Mesa College, Michelle Thompson (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, Gail McCormick (editor), Animal Diversity Web Staff.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

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Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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acoustic

uses sound to communicate

benthic

Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

brackish water

areas with salty water, usually in coastal marshes and estuaries.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

electric

uses electric signals to communicate

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

induced ovulation

ovulation is stimulated by the act of copulation (does not occur spontaneously)

internal fertilization

fertilization takes place within the female's body

magnetic

(as perception channel keyword). This animal has a special ability to detect the Earth's magnetic fields.

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

ovoviviparous

reproduction in which eggs develop within the maternal body without additional nourishment from the parent and hatch within the parent or immediately after laying.

piscivore

an animal that mainly eats fish

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

venomous

an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

References

Capape, C. 1993. New data on the reproductive biology of the thorny stingray, Dasyatis centroura from off the Tunisian coasts. Pp. 73-80 in J Wourms, L Demski, eds. Environmental Biology of Fishes. Netherlands: Eugene K. Balon.

Chisholm, L., I. Whittington, A. Fischer. 2004. A review of Dendromonocotyle (Monogenea: Monocotylidae). Folia Parasitologica, 51: 123-130.

Dulcic, J., I. Jardas, V. Onofri, J. Bolotin. 2003. The roughtail stingray Dasyatis centoura (Pisces: Dasyatidae) and spiny butterfly ray Gymnura altavela (Pisces: Gymnuridae) from the southern Adriatic. Journal of the Marine Biological Association of the United Kingdom, 83: 871-872.

Grey, M., A. Blais, B. Hunt, A. Vincent. 2006. The USA's international trade in fish leather, from a conservation perspective. Environmental Conservation, 33: 100-108.

MacEachran, J. 2004. Rajiformes (Skates and Rays). Pp. 173-188 in M Hutchins, A Evans, J Jackson, eds. Grzimek's Animal Life Encyclopedia, Vol. 4, 2 Edition. Detroit: Gale. Accessed April 13, 2010 at http://go.galegroup.com/ps/retrieve.do?retrieveFormat=PDF_FROM_CALLISTO&inPS=true&prodId=GVRL&userGroupName=san28139&workId=grze_04_01661-p.pdf|grze_04_01676-p.pdf&docId=GALE|CX3406700248&callistoContentSet=GALE&isAcrobatAvailable=true.

Mitchill, 2008. "Florida Museum of Natural History Ichthyology Department" (On-line). Roughtail Stingry. Accessed April 03, 2010 at http://www.flmnh.ufl.edu/fish/Gallery/Descript/RtailStingray/RtailStingray.html.

Ribeiro-Prado, C., A. Amorim. 2008. "FISHERY BIOLOGY ON PELAGIC STINGRAY PTEROPLATYTRYGON" (On-line). Accessed April 25, 2010 at http://www.iccat.int/Documents/CVSP/CV062_2008/no_6/CV062061883.pdf.

The IUCN Red List of Threatened Species, 2010. "Dasyatis centroura" (On-line). Accessed March 15, 2010 at http://www.iucnredlist.org/apps/redlist/details/63152/0.

Weinheimer, M., R. Jonna. 2003. "ADW: Dasyatidae: Information" (On-line). Accessed May 04, 2010 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Dasyatidae.html.