Biology:Kuhl's maskray

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Short description: Species of cartilaginous fish


Kuhl's maskray
Blue-spotted Stingray (Neotrygon kuhlii) (8465011759).jpg
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Batoidea
Order: Myliobatiformes
Family: Dasyatidae
Genus: Neotrygon
Species:
N. kuhlii
Binomial name
Neotrygon kuhlii
(J. P. Müller & Henle, 1841)

Kuhl's maskray (Neotrygon kuhlii), also known as the blue-spotted stingray, blue-spotted maskray, or Kuhl's stingray, is a species of stingray of the family Dasyatidae. It was recently changed from Dasyatis kuhlii in 2008 after morphological and molecular analyses showed that it is part of a distinct genus, Neotrygon.[2] The body is rhomboidal and colored green with blue spots. Maximum disk width is estimated 46.5 cm (18.3 in).[3] It is popular in aquaria, but usually not distinguished from the blue-spotted ribbontail ray. The ribbontail has a rounded body, is a brighter green with brighter blue and more vivid spots, but Kuhl's maskray is larger.[4] The stingray's lifespan is estimated at 13 years for females and 10 years for males.[5] The blue-spotted stingray preys on many fish and small mollusks. It is also generally found from Indonesia to Japan, and most of Australia. Kuhl's maskray also is targeted by many parasites, such as tapeworms, flatworms, and flukes.

Taxonomy

Kuhl's maskray was discovered by Heinrich Kuhl in Java, Indonesia. The population size of this species is greatly debatable due to the five different species of rays in Indonesia. Also, two different subgroups are known, the Java and Bali forms.[6] The distinct difference between the two strains is their size, with the Bali being much larger than the Java.[7] On the familial level, the family Dasyatidae is made up of 9 genera and 70 species. The species in Neotrygon are called maskrays, because of the color pattern around their eyes.

Description and behavior

The full body of a blue-spotted stingray, showing the black-and-white-striped tail

Kuhl's maskrays have a flat, disc-like, rhomboid body up to 47 cm (19 in) in diameter and 70 cm (28 in) in total length.[7][8] Their coloring is a dark green with blue spots with a light white underbelly, also known as countershading. Their snouts are very short and broadly angular along with an angular disc.[7] The rays' bright coloration serves as a warning for their venomous spines. The rays have a very long tail accommodating two venomous spines on its base. Their tails are about twice as long as their bodies, and the barbs or spines are two different sizes, one being very large and the other medium in size. Kuhl's maskrays have bright yellow eyes that are positioned to allow them a wide angle of view. Since their gills are located ventrally, the spiracles allow water to reach the gills while resting or feeding on the benthos. The spiracles are located directly behind the eyes. The mouth is located on the ventral side of the body, which promotes the unique foraging technique of stingrays.[9] Rays are normally solitary individuals, but can occur in groups. One unique characteristic of Kuhl's maskrays is that they bury themselves in the sand only to hide from predators, unlike most stingrays, which bury themselves regularly to hunt.[9]

Shrimp, one of the blue-spotted stingray's food sources

Diet

Kuhl's maskray feeds on shrimp, small bony fish, mollusks, crabs, and worms. Because this ray is a shallow-bottom feeder, it has a small variety of marine life on which to prey. It overpowers its prey by pinning it to the bottom of the seafloor with its fins. This ray has numerous tiny teeth, with the lower jaw being slightly convex. Like most stingrays, it has plate-like teeth to crush prey.

Reproduction

Kuhl's maskray is ovoviviparous. The embryos are retained in eggs within the mother's body until they are ready to hatch. The embryos receive nourishment from the mothers' uterine fluid. Mothers give birth to up to seven pups per litter; these pups range from 6 to 13 in (150 to 330 mm) long at birth.[10] The blue-spotted stingray passes its offspring 32 sets of chromosomes.[7] The female also has an annual reproductive cycle. The mating season is in October and November, and the ovulating season is in the Australian summer (December 1- February 28/29), which coincides with the embryonic development.[11]

Habitat

Blue-spotted maskray range map

The blue-spotted stingray is commonly found in waters of depths above 90 m (295 ft), being commonly found in sand and mudflats, but is also encountered near rocky coral reefs and sea grass beds. This stingray is found in a tropical climate at 29°N to 31°S, and 20°E to 171°W.[7] At high tide, the blue-spotted stingray moves into the shallow lagoons and reef flats.[6] It is found in northern Australia , Kenya, Madagascar , Mauritius, Somalia, the east coast of South Africa , and India , and in almost the entire continental waters of Asia, including the Sea of Japan, Yellow Sea, East China Sea, Philippine Sea, Sulu Sea, Java Sea, Banda Sea, Celebes Sea, Andaman Sea, the Bay of Bengal, and the Arabian Sea.[12]

The body of a Kuhl's maskray is more angular, which distinguishes it from the blue-spotted ribbontail ray.

Threats and protected areas

Queensland, Australia, has many areas for high protection of Kuhl's maskrays, three being the Shoalwater, Corio Bay's Area Ramsar Site, and the Great Barrier Reef Marine Park. A major threat to this stingray is the destruction of coral reefs mainly in the north-western Pacific. The rays dwell in these reefs and the destruction and pollution from fertilizers and pesticides hurt them.[9] The ray is commonly caught in the Java Sea by fishermen trawling and by Danish seine boats in large quantities. The blue-spotted stingray is the second-most significant species of the shark, ray, and skate family to be fished, contributing to about 700 kg (1,500 lb) per boat in 2006–2007.[13]

Predators

Larger elasmobranchs, such as hammerhead sharks, prey on Kuhl's maskrays. The rays' coloration is a warning for the highly venomous barbs, thus few animals attempt to overpower them.[10][14] The hammerhead shark uses its head to pin down this stingray, while it is in shock and much weaker.[15]

Human interaction

Due to the unique characteristics of this ray, it is commonly found in pet trade, but many people ignore the fact that the fully mature size of the ray exceeds the capacity of many household aquaria.[9] Kuhl's maskray is generally fished for its meat, being either smoked and salted or dried for local markets, but inexpensive due to its small size.[7][13] It is caught in mass in bottom trawl, trammel, and fish traps. Kuhl's maskray is very venomous and it has a barb about 12 in (300 mm) long. The venom contains serotonin, 5' nucleotidase, and phosphodiesterase.[16]

The skin of the blue-spotted stingray is often used for drums, such as on the Arab and Turkish darbuka goblet drum and riq tambourine.

Parasites

Many parasites can inhabit the blue-spotted stingray:[17]

Common Class Group Parasite
Tapeworms Cestodes, Cephalobothriidae Cephalobothrium longisegmentum and Tylocephalum kuhli
Tapeworms Cestodes, Mixodigmatidae Trygonicola macroporus
Tapeworms Cestodes, Onchobothriidae Acanthobothrium bengalens, Acanthobothrium confusum, Acanthobothrium herdmani, and Acanthobothrium pingtanensis
Tapeworms Cestodes, Phyllobothriidae Echeneibothrium trygonis, Phyllobothrium ptychocephalum, Rhinebothrium shipleyi, Scalithrium shipleyi, and Scalithrium trygonis
Flatworms Monogeneans, Monocotylidae Dendromonocotyle kuhlii, Heterocotyle chinensis, Monocotyle kuhlii, and Monocotyle tritestis
Flukes Trematodes, Monocotylidae Prosorhynchus clavatum
Flukes Trematodes, Didymozoidae Didymozoid larva
External video
Blue spotted stingray swimming YouTube
Hand feeding a blue spotted stingrayYouTube
How Whales Eat Sharks[|permanent dead link|dead link}}] National Geographic

Applications

Two short peptides identified from the hydrolyzed proteins of this species showed protective effects against the oxidation of lipids, DNA and proteins. The potential application of the peptides as functional food ingredients or nutraceuticals has been proposed.[18]

References

  1. Kyne, P.M.; Finucci, B. (2018). "Neotrygon kuhlii". IUCN Red List of Threatened Species 2018: e.T116847578A116849874. doi:10.2305/IUCN.UK.2018-2.RLTS.T116847578A116849874.en. https://www.iucnredlist.org/species/116847578/116849874. Retrieved 12 November 2021. 
  2. Last, P. R.; White, W. T. (2008). "Resurrection of the genus Neotrygon Castelnau (Myliobatoidei: Dasyatidae) with the descriptions of Neotrygon picta sp. nov., a new species from northern Australia". CSIRO Marine & Atmospheric Research. http://bionames.org/bionames-archive/issn/1833-2331/22/315.pdf. 
  3. Pierce, S. J.; Pardo, S. A.; Bennett, M. B. (2009). "Reproduction of the Blue-spotted maskray Neotrygon kuhlii (Myliobatoidei: Dasyatidae) in southeast Queensland, Australia". Journal of Fish Biology 74 (6): 1291–1308. doi:10.1111/j.1095-8649.2009.02202.x. PMID 20735632. 
  4. (Randall 2005)
  5. Pierce, S. J.; Bennett, M. B. (2009). "Validated annual band-pair periodicity and growth parameters of blue-spotted maskray Neotrygon kuhlii from southeast Queensland, Australia". Journal of Fish Biology 75 (10): 2490–2508. doi:10.1111/j.1095-8649.2009.02435.x. PMID 20738504. 
  6. 6.0 6.1 "Dasyatis kuhlii". IUCN Red List of Threatened Species 2007. 2007. https://www.iucnredlist.org/details/161590/0. Retrieved November 28, 2011. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 "Dasyatis kuhlii- Blue-spotted stingray (Müller & Henle, 1841)". FishBase. 2010. http://www.fishbase.org/Summary/speciesSummary.php?ID=4508&genusname=Dasyatis&speciesname=kuhlii. 
  8. "Species Fact Sheet-- Rays". Shark Bay Ecosystem Research Project. http://www2.fiu.edu/~heithaus/SBERP/pdfs/species/raysfs.pdf. 
  9. 9.0 9.1 9.2 9.3 "Blue Spot Stingray". John G. Shedd Aquarium. http://sea.sheddaquarium.org/sea/fact_sheets.asp?id=109#. 
  10. 10.0 10.1 Bester, Cathleen (November 11, 2011). "Blue Spotted Stingray". Ichthyology Department, Florida Museum of Natural History. http://www.flmnh.ufl.edu/fish/gallery/Descript/bluespottedsray/bluespottedsray.html. 
  11. Pierce, S. J.; Pardo, S. A.; Bennett, M. B. (2009). "Reproduction of the blue-spotted maskray Dasyatis kuhlii (Myliobatoidei: Dasyatidae) in southeast Queensland, Australia". Journal of Fish Biology 74 (6): 1291–308. doi:10.1111/j.1095-8649.2009.02202.x. PMID 20735632. 
  12. "Dasyatis kuhlii (Müller & Henle, 1841)". World Register of Marine Species. 2009. http://www.marinespecies.org/aphia.php?p=taxdetails&id=398330. 
  13. 13.0 13.1 "Dasyatis kuhlii (Bluespotted Stingray)". IUCN Red List of Threatened Species December 20, 2011. December 20, 2011. https://www.iucnredlist.org/details/161590/0. 
  14. Pablico, Grace Tolentino (June 23, 2006). "Predator Summary — Dasyatis Kuhlii". FishBase. http://www.fishbase.tw/TrophicEco/PredatorSummary.php?vpredatstage=juv.%2Fadults&genusname=Dasyatis&speciesname=kuhlii&vstockcode=5631&vpreystage=juv.%2Fadults&vpredatorgroup=Delphinidae&vpredatorname=Orcinus+orca. 
  15. "Hammerhead Shark". Aquatic Community. 2006. http://www.aquaticcommunity.com/sharkfish/hammerheadshark.php. 
  16. Auerbach, M.D., Paul S. (April 20, 2009). "The Tragic Death of Steve Irwin". Divers Alert Network. http://www.diversalertnetwork.org/default.aspx?a=news&id=845. 
  17. "Host-parasite Database". Natural History Museum. November 13, 2011. http://www.nhm.ac.uk/research-curation/research/projects/host-parasites/database/results.jsp?location=&paragroup=&showparasites=on&paraspecies=&fmhostgenus=Contains&fmparagenus=Starts+with&showrefs=on&fmsubgroup=Starts+with&search=Search&groupby=parasite&pstatus=&showhosts=on&paragenus=&fmparaspecies=Starts+with&subgroup=&showgrouping=on&fmhostspecies=Starts+with&hstate=&hostgenus=Dasyatis&hostspecies=kuhlii. 
  18. Wong, Fai-Chu; Xiao, Jianbo; Ong, Michelle G-Ling; Pang, Mei-Jing; Wong, Shao-Jun; Teh, Lai-Kuan; Chai, Tsun-Thai (2019). "Identification and characterization of antioxidant peptides from hydrolysate of blue-spotted stingray and their stability against thermal, pH and simulated gastrointestinal digestion treatments". Food Chemistry 271: 614–622. doi:10.1016/j.foodchem.2018.07.206. PMID 30236723. https://doi.org/10.1016/j.foodchem.2018.07.206. Retrieved 2022-01-13. 

Further reading


External links

Wikidata ☰ Q950415 entry