Dasyatis brevicaudata

Giant black ray

(Also: Giant stingray; New Zealand short-tail stingaree; Schreiners ray; Short-tail stingray)

Features
By Robert Krebs

Geographic Range

Short-tail stingrays ( Dasyatis brevicaudata ) are found in the Indian Ocean, off the coasts of Australia and New Zealand. Along the African coast, these stingrays are limited to south of the Tropic of Capricorn. Their breeding grounds and nurseries are concentrated on the northwestern side of Poor Knights Island, New Zealand.

Habitat

Short-tail stingrays are bottom-dwellers in temperate waters. They are found on the seafloor in harbors, coastal bays, large inlets, and coastal reefs. Away from the coasts, they have typically been found at depths around 150 m, and as deep as 476 m. Sometimes they are found in underwater caves and under large overhangs.

Research of gene flow in short-tail stingrays revealed that they do not migrate long distances; environmental effects limit mobility for mating and nursing.

  • Other Habitat Features
  • caves

Physical Description

Short-tail stingrays are grey on their dorsal sides and white on their ventral sides. Their bodies are similar to an oblong disc or a blunt diamond shape. There is a lack of detailed physical measurements comparing male and female short-tail stingrays. Reports state that male short-tail stingrays can weigh up to 350 kg; females can measure up to 109 cm and weigh up to 45.34 kg. These stingrays are the largest rays in the world, with males measuring up to 4.3 m long and 3 m wide.

Offspring are about 36 cm disc width at birth. Le Port et al. (2012) report juveniles with a disc width range of 1.0 to 1.5 m. Their bodies are smooth, except for their tails, which are skinny and serrated. Their tails average 22 cm long, with a thick base that narrows out. Their tails are venomous. They can have multiple venomous tails, but there is always one main tail that can grow up to 30 cm. Short-tail stingrays have tails made of cartilage. The venom that these tails contain is a neurotoxin that consists of phosphodiesterases, 5’ nucleotidases, serotonin and other proteins.

The eyes of short-tail stingrays are small and medial lateral to each other. They have oval-shaped nostrils on their anterior sides, about 13 cm from the ventral view to the mouth. The ratio of rods to cones in their retina is 10:1, indicating that short-tail stingrays are diurnal. However, the low amount of cones suggests a preference for nocturnal activity.

Short-tail stingrays have 10 gill slits, which are positioned in diagonal lines and form an incomplete "V" shape. The gill slits closest to their mouths are the most distal. They also have other forms of respiratory holes, known as spiracles, located behind and adjacent to their eyes. There are usually 25 series of teeth and about 45 to 50 rows of teeth across their jaw lines.

  • Sexual Dimorphism
  • male larger

Development

Short-tail stingrays are ovoviviparous, which means offspring start out as eggs, hatch inside the bodies of their mothers, and are born live. Newborns stay within the area of seafloor in which they were born and will being to migrate as they age and grow larger.

There is limited birthing information on short-tail stingrays, but there is information on closely-related round stingrays ( Urolophus halleri ). Once pups are born, they will travel to the sea floor and remain within 180 m from land. When the offspring are old enough (when their body growth as ceased), they will start traveling farther out, where other adults are, and search for larger prey items. Short-tail stingray offspring are about 36 cm disc width at birth. Juveniles with disc widths of 1.0 to 1.5 m have been reported. The rate of growth is not published, but they are suspected to exhibit indeterminate growth (similar to all cartilaginous fish).

Reproduction

Leport et al. (2012) established that temperature and daylight are triggers to short-tail stingray reproduction cycles and, if those are altered, then reproduction is lacking. While mating, male short-tail stingrays will swim upside down, underneath females, and will bite the discs of females. Then male stingrays insert their claspers into the cloacae of females, and also nudge their abdomens.

Female short-tail stingrays are suspected to have a similar mating system as other related stingrays. Southern stingrays ( Dasyatis americana ) will mate with several males (polyandrous), one at a time. Males swim posterior to a single female in a cluster. A male will then grab onto the pectoral disc of the female (the whole body) and the male will copulate by inserting his clasper into her cloaca. The claspers leave scars on the underside of the female stingray.

There is little information for short-tail stingrays, but they may be comparable to closely-related rough-tail stingrays ( Dasyatis centroua ), black stingrays ( Dasyatis thetidis ), and southern stingrays ( Dasyatis americana ). These related stingrays have similar physiological features as well as reproductive features. The gestational period for these relatives has not been determined, but frequent mating occurrences and frequent births are documented. Breeding months span from late spring to autumn (approximately May to August). The number of offspring for rough-tail stingrays is typically 6 to 10 offspring (12 at most).

Due to the difficulty of determining age in living stingrays, disc width is used instead of age. Therefore, age of first reproduction is unreported.

Short-tail stingrays are lipid histotrophs, meaning mothers produce uterine milk for their offspring. Short-tail stingray offspring are born at about 36 cm disc width at birth. There is no parental care after birth, and offspring are immediately independent.

There is no recorded evidence of parental investment in short-tail stingrays. Offspring are born either inshore or offshore, on the outer shelf and uppermost slope; offspring travel straight to the sea floor. Sometimes they are birthed in caves, but the offspring can be found in sandy bays, estuaries, harbors, or at rocky reefs for protection and food. Females provide no further care for their young beyond pre-hatching sustenance. Males provide no parental investment beyond the act of mating.

  • Parental Investment
  • pre-hatching/birth
    • provisioning
      • female

Lifespan/Longevity

The expected life span for short-tail stingrays in captivity is 70 to 80 years, while short-tail stingrays have a life span of 15 to 25 years in the wild. The oldest short-tail stingray has been recorded to be 30 years of age in the wild.

Behavior

Short-tail stingrays are natatorial and diurnal. However, their rod-to-cone ratio suggests that they may be active nocturnally as well. They tend to stay in certain coastal areas near where they are born, but have been frequently found to migrate to other coasts within temperate waters. Short-tail stingrays are defensive by nature and harmless unless they feel threatened. They can defensively sting with their venomous tail or tails.

Home Range

Short-tail stingrays have no specific home range and do not defend a territory.

Communication and Perception

Short-tail stingrays have pores and canals, or lateral lines, that consist of mechanoreceptors that have a mechano-tactile function. These are located on the ventral sides of this elasmobranch species. These lateral lines deal with vibrations mainly for predation, but they are also capable of conducting electricity for communication, defense, and detecting partners. They also use these mechanoreceptors to detect water movement around them. It has been discovered in elasmobranch species that lateral lines are for detecting other organisms, either to catch prey or avoid predators. For short-tail stingrays there have been discoveries that the nonporous ventral sides of their bodies are 2 to 10 times more sensitive to physical contact compared to vibrations or noncontact pressure.

When mating, males and females interact via tactile communications. Male claspers are involved in internal reproduction.

Short-tail stingrays have small eyes. The ratio of rods to cones is 10:1 in their retina, indicating that short-tail stingrays are diurnal. However, the low amount of cones suggests a preference for nocturnal activity.

Food Habits

Short-tail stingrays consume various types of crustaceans, cephalopods, arthropods, and small fish (bony and non-bony). They also eat smaller cnidarians and sometimes they consume plants.

  • Animal Foods
  • fish
  • mollusks
  • aquatic crustaceans
  • cnidarians
  • other marine invertebrates

Predation

Humans ( Homo sapiens ) catch short-tail stingrays for food. They are considered a prize by commercial fisheries. Other animals that prey on short-tail stingrays include sharks and killer whales ( Orcinus orca ). Stingrays, in general, use lateral lines to detect water movement and avoid predation. Short-tail stingrays also use cryptic camouflage in order to eat or avoid being eaten.

Ecosystem Roles

Short-tail stingrays prey on crustaceans, cephalopods, cnidarians, arthropods, and small fish. Sharks, killer whales ( Orcinus orca ), and humans are known predators of short-tail stingrays.

Common parasites that have been found to associate themselves with short-tail stingrays include monogeneans ( Heterocotyle tokoloshei and Dendromonocotyle tsutsumii ) and tapeworms ( Acanthobothrium adlardi , Dollfusiella ocallaghani , Eutetrarhynchus ocallaghani , Prochristianella mooreae , Pterobothrium lintoni , Pterobothrium platycephalum , Rhinebothrium dasyatidis , and Trimacracanthus aetobatidis ). The only isopod parasites known thus far are of the genus Gnathia .

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Short-tail stingrays usually do not attack people, so they are often visited by people generating tourism. There is a market for short-tail stingrays in the food industry.

Economic Importance for Humans: Negative

Short-tail stingrays have venomous tails that can be lethal to humans, but they only sting as a defensive measure. Their stingers are made of cartilage and are shaped like a tapered whip with doubly-serrated sides. These tails can reach up to 30 cm in length. The venom consists mainly of neurotoxins (phosphodiesterases, 5’ nucleotidases, serotonin) and other proteins. Symptoms of the venom include weakness, severe pain, necrosis, nausea, headaches, hypotension, fasciculation, dysrhythmia, and vertigo (because of the neurotoxins). The respiratory and circulatory systems are at the biggest risk when this venom enters the body. Common measures for treating a stingray victim are use of opioids for pain relief and then surgery. A hot water bath, saline solution, and surgical removal of fragments from the stinger are usual steps for patients. Using heat reduces toxin potency.

  • Negative Impacts
  • injures humans

Conservation Status

Short-tail stingrays are listed as a species of “Least Concern” on the IUCN Red List. They have no special status on the US Federal List, State of Michigan list, and CITES. In 1994, short-tail stingrays were of concern, but not endangerment, due to overfishing. Some issues were the time periods of sexual maturity and the fertility of short-tail stingrays. Leport et al. (2012) found that temperature and daylight are triggers to the reproduction cycle of short-tail stingrays; if those are altered, then reproduction gets delayed. Rizzari et al. (2017) found a negative correlation between boat activity and short-tail stingray health. Boats are capable of harming short-tail stingrays and people on boats sometimes fish for stingrays for food. Main threats to short-tail stingrays are predators, like sharks and killer whales ( Orcinus orca ), and commercial fishing.

Legal regulations exist along the coast of Poor Knights Island (New Zealand) and parts of Australia in order to control human tourism and short-tail stingray harvesting. Attempts have been made to save the species by means of captive breeding at aquatic centers in South Africa, Australia, and New Zealand; however, it has been difficult for them to reproduce and not kill their mates. Le Port et al. (2012) suggest that protecting and encouraging breeding and nursery grounds would be an act of conserving short-tail stingrays.

Other Comments

Short-tail stingrays are the species of stingray responsible for killing Steve Irwin ("The Crocodile Hunter") while filming in 2006.

Encyclopedia of Life

Contributors

Robert Krebs (author), Radford University, Lauren Burroughs (editor), Radford University, Layne DiBuono (editor), Radford University, Lindsey Lee (editor), Radford University, Karen Powers (editor), Radford University, Galen Burrell (editor), Special Projects.

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

native range

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

native range

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

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

native range

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

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical

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

saltwater or marine

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

pelagic

An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

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.

reef

structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ectothermic

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

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.

venomous

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

indeterminate growth

Animals with indeterminate growth continue to grow throughout their lives.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

sexual

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

fertilization

union of egg and spermatozoan

internal fertilization

fertilization takes place within the female's body

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.

natatorial

specialized for swimming

diurnal
  1. active during the day, 2. lasting for one day.
nocturnal

active during the night

motile

having the capacity to move from one place to another.

nomadic

generally wanders from place to place, usually within a well-defined range.

migratory

makes seasonal movements between breeding and wintering grounds

visual

uses sight to communicate

tactile

uses touch to communicate

chemical

uses smells or other chemicals to communicate

electric

uses electric signals to communicate

vibrations

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

visual

uses sight to communicate

tactile

uses touch to communicate

vibrations

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

electric

uses electric signals to communicate

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.

food

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

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

venomous

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

carnivore

an animal that mainly eats meat

piscivore

an animal that mainly eats fish

molluscivore

eats mollusks, members of Phylum Mollusca

omnivore

an animal that mainly eats all kinds of things, including plants and animals

References

Adams, S. 2007. Bites and stings: Marine stings. Journal of the Accident and Medical Practitioners Association (JAMPA) , 4/1: 1-10. Accessed June 22, 2019 at https://pdfs.semanticscholar.org/4d77/905c64e485589f1733325e0f7def57e13d62.pdf .

Babel, J. 1967. Reproduction, life history, and ecology of the round stingray, Urolophus halleri Cooper. State of California, the Resources Agency, Department of Fish and Game Fish Bulletin , 137: 1-104. Accessed February 28, 2019 at http://content.cdlib.org/view?docId=kt6t1nb1vn&brand=calisphere .

Babington, C., A. Gunther, W. Dallas, W. Francis. 1875. Dasyatis brevicaudata. The Annals and Magazine of Natural History , 16: 1.

Baker, J., K. Rodda, S. Shepherd. 2006. Chapter 27: Sharks and rays of Gulf St Vincent. Pp. 367-382 in Natural History Of Gulf St Vincent . North Terrace, Adelaide, Australia: Royal Society of South Australia.

Basusta, N., J. Sulikowaski. 2012. The oldest estimated age for roughtail stingray [Dasyatis centroura (Mitchill, 1815)] from the Mediterranean Sea. Journal of Applied Ichthyology , 28: 641–642.

Bester, C. 2018. "Dasyatis brevicaudata" (On-line). Discover Fishes. Accessed February 06, 2019 at https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/dasyatis-brevicaudata/ .

Braekevelt, C. 1995. Retinal photoreceptor fine structure in the short-tailed stingray (Dasyatis brevicaudata). Histology and Histopathology , 9/3: 507-514.

Branco-Nunes, I., D. Veras, P. Oliveira, F. Hazin. 2016. Vertical movements of the southern stingray, Dasyatis americana (Hildebrand & Schroeder, 1928) in the Biological Reserve of the Rocas Atoll, Brazil. Latin American Journal of Aquatic Reserach , 44/2: 216-227.

Bray, D. 2018. "Bathytoshia brevicaudata" (On-line). Fishes of Australia. Accessed February 05, 2019 at http://fishesofaustralia.net.au/home/species/2020 .

Butcher, P., V. Peddemors, J. Mandelman, S. McGrath, B. Cullis. 2015. At-vessel mortality and blood biochemical status of elasmobranchs caught in an Australian commercial longline fishery. Global Ecology and Conservation , 3: 878-889.

Carrier, J., J. Musick, M. Heithaus. 2012. Biology of Sharks and their Relatives . Boca Raton, Florida: CRC press. Accessed March 05, 2019 at ISBN: 9781439839249 .

Chapman, D., M. Corcorana, G. Harvy, S. Malan, M. Shivjia. 2003. Mating behavior of southern stingrays, Dasyatis americana (Dasyatidae). Environmental Biology of Fishes , 68: 241–245.

Chishom, L., I. Whittington, A. Fischer. 2004. A review of Dendromonocotyle (Monogenea: Monocotylidae) from the skin of stingrays and their control in public aquaria. Folia Parasitologica , 51: 123-130.

Dodrill, J., C. Richardson. 1981. Inshore occurrence and nuptial behavior of the roughtail stingray, Dasyatls centroura (Dasyatidae), on the continental shelf, east central Florida. Northeast Gulf Science , 5/1: 59-62.

Duffy, C., M. Francis, B. Finucci, M. Dunn, R. Ford, J. Rolfe. 2017. Conservation status of New Zealand chondrichthyans (chimaeras, sharks and rays). New Zealand Threat Classification Series 23 , None: 1-13. Accessed June 22, 2019 at https://www.doc.govt.nz/Documents/science-and-technical/nztcs23entire.pdf .

Garman, S. 1913. The Plagiostomia: Sharks, skates, and rays. Memoirs of the Museum of Comparative Zoology at Harvard College , 36: 1-515. Accessed June 22, 2019 at https://www.biodiversitylibrary.org/bibliography/43732#/summary .

Garrick, J. 1954. Studies on New Zealand elasmobranchii. Part II. A description of Dasyatis brevicaudatus (Hutton), Batoidei, with a review of records of the species outside New Zealand. Transactions and Proceedings of the Royal Society of New Zealand , 82: 189-198.

Gilliam, D., K. Sullivan. 1993. Diet and feeding habits of the southern stingray Dasyatis americana in the central Bahamas. Bulletin of Marine Science , 52/3: 1007-1013.

Hadhazy, A. 2006. "I thought stingrays were harmless, so how did one manage to kill the “Crocodile Hunter?”" (On-line). ScienceLine. Accessed June 13, 2019 at https://scienceline.org/2006/09/ask-grant-irwin/ .

Hart, N., T. Lisney, S. Collin. 2006. Visual communication in elasmobranchs. Pp. 338-392 in Communication in Fishes . Enfield, NJ: Science Publishers Inc..

Jordan, L., S. Kaliura, M. Gordon. 2009. Functional consequences of structural differences in stingray sensory systems, Part I: Mechanosensory lateral line canals. The Journal of Experimental Biology , 212: 3037-3043.

Last, P., Fahmi, G. Naylor. 2010. Pastinachus stellurostris sp. nov., a new stingray (Elasmobranchii: Myliobatiformes) from Indonesian Borneo. Pp. 129-139 in Descriptions of New Sharks and Rays from Borneo , Vol. Paper 032. Clayton, Australia: CSIRO Marine and Atmospheric Research. Accessed February 21, 2019 at https://www.cmar.csiro.au/docs/Descriptions-of-sharks-and-rays-from-Borneo-small.pdf .

Le Port, A., S. Lavery. 2011. Population structure and phylogeography of the short-tailed stingray, Dasyatis brevicaudata (Hutton 1875), in the southern hemisphere. Journal of Heredity , 103/2: 174-185.

Le Port, A., S. Lavery, J. Montgomery. 2012. Conservation of coastal stingrays: Seasonal abundance and population structure of the short-tailed stingray Dasyatis brevicaudata at a marine protected area. ICES Journal of Marine Science , 69/8: 1427-1435.

Lim, K., P. Lim, V. Chong, K. Loh. 2015. Molecular and morphological analyses reveal phylogenetic relationships of stingrays focusing on the family Dasyatidae (Myliobatiformes). PLoS ONE , 10/5: e0120518. Accessed February 13, 2019 at https://doi.org/10.1371/journal.pone.0129411 .

Lockett, M., D. Hoese. 2018. "Bathytoshia brevicaudata" (On-line). Australian Government Department of Energy and Conservation. Accessed February 04, 2019 at https://biodiversity.org.au/afd/taxa/Bathytoshia_brevicaudata .

Maruska, K., T. Tricas. 1998. Morphology of the mechanosensory lateral line system in the Atlantic stingray, Dasyatis sabina: The mechanotactile hypothesis. Journal of Morphology , 238/1: 1-22.

Molteno, T., W. Kennedy. 2009. Navigation by induction-based magnetoreception in elasmobranch fishes. Journal of Biophysics , 2009: Article ID 380976.

Musick, J., J. Ellis. 2005. Reproductive evolution of Chondrichthyans. Pp. 45-79 in Reproductive Biology and Phylogeny of Chondrichthyes: Sharks, Batoids, and Chimaeras, Volume 3 . Boca Raton, FL: CRC Press.

Oldfield, R. 2005. Biology, husbandry, and reproduction of freshwater stingrays. Tropical Fish Hobbyist , 53/12: 114-116.

Ramsden, S., C. Cotton, M. Curran. 2017. Using acoustic telemetry to assess patterns in the seasonal residency of the Atlantic stingray Dasyatis sabina. Environmental Biology of Fishes , 100/2: 89-98.

Rizzari, J., J. Semmens, A. Fox, C. Huveneers. 2017. Observations of marine wildlife tourism effects on a non-focal species. Journal of Fish Biology , 91/3: 981-988.

Schieber, N., S. Collin, N. Hart. 2012. Comparative retinal anatomy in four species of elasmobranch. Journal of Morphology , 273/4: 423-440.

Summers, A. 2000. Stiffening the stingray skeleton - An investigation of durophagy in myliobatid stingrays (Chondrichthyes, Batoidea, Myliobatidae). Journal of Morphology , 243/2: 113-126.

Vaughan, D., L. Chisholm. 2010. Heterocotyle tokoloshei sp. nov. (Monogenea, Monocotylidae) from the gills of Dasyatis brevicaudata (Dasyatidae) kept in captivity at Two Oceans Aquarium, Cape Town, South Africa: Description and notes on treatment. Acta Parasitologica , 55/2: 108-114.

Visser, I. 2005. First observations of feeding on thresher (Alopias vulpinus) and hammerhead (Sphyrna zygaena) sharks by killer whales (Orcinus orca) specialising on elasmobranch prey. Aquatic Mammals , 31/1: 83-88.

Yeldan, H., A. Manasirh. 2009. Age, growth and feeding of the common stingray (Dasyatis pastinaca, L., 1758) in the Cilician coastal basin, northeastern Mediterranean Sea. Journal of Ichthyology , 25/S1: 98-102.

Yopak, K. 2012. Neuroecology of cartilaginous fishes: The functional implications of brain scaling. Journal of Fish Biology , 80/5: 1968-2023.

van der Westhuizen, A., P. van der Westhuizen. 2016. Extension of known distribution range: Short-tail stingray Dasyatis brevicaudata. Biodiversity Observations , 7: 1-3.

US Department of Energy. Ecological characterization of the lower Everglades, Florida Bay, and the Florida Keys. NTIS No. PB83-141978. FWS/OBS-82/58.1. Contract No. 14-12-0001-30036.. Metairie, LA: U.S. Fish and Wildlife Service. 1982.

To cite this page: Krebs, R. 2020. "Dasyatis brevicaudata" (On-line), Animal Diversity Web. Accessed {%B %d, %Y} at https://animaldiversity.org/accounts/Dasyatis_brevicaudata/

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