Kuhl's maskray

{{Speciesbox

| image = Blue-spotted Stingray (Neotrygon kuhlii) (8465011759).jpg

| status = DD

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=Kyne, P.M. |author2=Finucci, B. |name-list-style=amp |year=2018 |title=Neotrygon kuhlii |page=e.T116847578A116849874 |doi=10.2305/IUCN.UK.2018-2.RLTS.T116847578A116849874.en |access-date=12 November 2021}}

| genus = Neotrygon

| species = kuhlii

| authority = (J. P. Müller & Henle, 1841)

| synonyms =

| range_map = Bluespotted range map.png

| range_map_caption = Blue-spotted maskray range map

}}

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.{{cite web|title=Resurrection of the genus Neotrygon Castelnau (Myliobatoidei: Dasyatidae) with the descriptions of Neotrygon picta sp. nov., a new species from northern Australia|last1=Last|first1=P. R.|last2=White|first2=W. T.|publisher=CSIRO Marine & Atmospheric Research|year=2008|url=http://bionames.org/bionames-archive/issn/1833-2331/22/315.pdf|access-date=2015-08-26|archive-date=2015-11-20|archive-url=https://web.archive.org/web/20151120221115/http://bionames.org/bionames-archive/issn/1833-2331/22/315.pdf|url-status=live}} The body is rhomboidal and colored green with blue spots. Maximum disk width is estimated {{convert|46.5|cm|abbr=on}}.{{cite journal |doi=10.1111/j.1095-8649.2009.02202.x |title=Reproduction of the Blue-spotted maskray Neotrygon kuhlii (Myliobatoidei: Dasyatidae) in southeast Queensland, Australia |year=2009 |last1=Pierce |first1=S. J. |last2=Pardo |first2=S. A. |last3=Bennett |first3=M. B. |journal=Journal of Fish Biology |volume=74 |issue=6 |pages=1291–1308 |pmid=20735632|bibcode=2009JFBio..74.1291P }} 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.{{Harv|Randall|2005|p=18}} The stingray's lifespan is estimated at 13 years for females and 10 years for males.{{cite journal |doi=10.1111/j.1095-8649.2009.02435.x |title=Validated annual band-pair periodicity and growth parameters of blue-spotted maskray Neotrygon kuhlii from southeast Queensland, Australia |year=2009 |last1=Pierce |first1=S. J. |last2=Bennett |first2=M. B. |journal=Journal of Fish Biology |volume=75 |issue=10 |pages=2490–2508 |pmid=20738504 |bibcode=2009JFBio..75.2490P }} 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.{{cite web|title=Dasyatis kuhlii |url=https://www.iucnredlist.org/details/161590/0|url-status=dead|archive-date=1 March 2018|archive-url=https://web.archive.org/web/20180301000000/https://www.iucnredlist.org/details/161590/0}} The distinct difference between the two strains is their size, with the Bali being much larger than the Java. 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

File:Bluespot stingray.jpg

Kuhl's maskrays have a flat, disc-like, rhomboid body up to {{cvt|47|cm}} in diameter and {{cvt|70|cm}} in total length.{{cite web|title=Species Fact Sheet-- Rays|publisher=Shark Bay Ecosystem Research Project|url=http://www2.fiu.edu/~heithaus/SBERP/pdfs/species/raysfs.pdf|access-date=December 18, 2011|archive-date=August 4, 2010|archive-url=https://web.archive.org/web/20100804141242/http://www2.fiu.edu/~heithaus/SBERP/pdfs/species/raysfs.pdf|url-status=live}} 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. 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.{{cite web|title= Blue Spot Stingray|publisher= John G. Shedd Aquarium|url= http://sea.sheddaquarium.org/sea/fact_sheets.asp?id=109#|access-date= December 18, 2011|url-status= dead|archive-url= https://web.archive.org/web/20120426061435/http://sea.sheddaquarium.org/sea/fact_sheets.asp?id=109|archive-date= April 26, 2012}} 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.

File:Shrimp.jpg

=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 {{convert|6|to|13|in|abbr=on}} long at birth.{{Cite web | last = Bester | first = Cathleen | title = Blue Spotted Stingray | publisher = Ichthyology Department, Florida Museum of Natural History | date = November 11, 2011 | url = http://www.flmnh.ufl.edu/fish/gallery/Descript/bluespottedsray/bluespottedsray.html | access-date = November 11, 2011 | archive-date = May 19, 2012 | archive-url = https://web.archive.org/web/20120519054325/http://www.flmnh.ufl.edu/fish/gallery/Descript/bluespottedsray/bluespottedsray.html | url-status = live }} The blue-spotted stingray passes its offspring 32 sets of chromosomes. 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.{{cite journal |doi=10.1111/j.1095-8649.2009.02202.x |title=Reproduction of the blue-spotted maskray Dasyatis kuhlii (Myliobatoidei: Dasyatidae) in southeast Queensland, Australia |year=2009 |last1=Pierce |first1=S. J. |last2=Pardo |first2=S. A. |last3=Bennett |first3=M. B. |journal=Journal of Fish Biology |volume=74 |issue=6 |pages=1291–308 |pmid=20735632|bibcode=2009JFBio..74.1291P }}

Habitat

The blue-spotted stingray is commonly found in waters of depths less than {{cvt|90|m|0}}, 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.{{FishBase|genus= Neotrygon|species= kuhlii|month= December|year=2011|ID=4508}} At high tide, the blue-spotted stingray moves into the shallow lagoons and reef flats. 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.{{cite WoRMS|author=Bailly, Nicolas|year=2009|id=398330|title= Dasyatis kuhlii (Müller & Henle, 1841)}}

Image:Blue spotted stingray NTB.jpg

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. 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 families to be fished, contributing to about {{cvt|700|kg}} per boat in 2006–2007.

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.{{Cite web| title = Predator Summary — Neotrygon kuhlii| author = Pablico, Grace Tolentino| publisher = FishBase| date = June 23, 2006| access-date = December 27, 2011| url = http://www.fishbase.tw/TrophicEco/PredatorSummary.php?vpredatstage=juv.%2Fadults&genusname=Dasyatis&speciesname=kuhlii&vstockcode=5631&vpreystage=juv.%2Fadults&vpredatorgroup=Delphinidae&vpredatorname=Orcinus+orca| archive-date = September 24, 2015| archive-url = https://web.archive.org/web/20150924013431/http://www.fishbase.tw/TrophicEco/PredatorSummary.php?vpredatstage=juv.%2Fadults&genusname=Dasyatis&speciesname=kuhlii&vstockcode=5631&vpreystage=juv.%2Fadults&vpredatorgroup=Delphinidae&vpredatorname=Orcinus+orca| url-status = live}} The hammerhead shark uses its head to pin down this stingray, while it is in shock and much weaker.{{Cite web|title = Hammerhead Shark|publisher = Aquatic Community|year = 2006|access-date = December 31, 2011|url = http://www.aquaticcommunity.com/sharkfish/hammerheadshark.php|archive-date = January 30, 2019|archive-url = https://web.archive.org/web/20190130105212/http://www.aquaticcommunity.com/sharkfish/hammerheadshark.php|url-status = live}}

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. 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. It is caught in mass in bottom trawl, trammel, and fish traps. Kuhl's maskray is very venomous and it has a barb about {{convert|12|in|abbr=on}} long. The venom contains serotonin, 5' nucleotidase, and phosphodiesterase.{{Cite web| last = Auerbach, M.D.| first = Paul S.| title = The Tragic Death of Steve Irwin| publisher = Divers Alert Network| date = April 20, 2009| access-date = December 31, 2011| url = http://www.diversalertnetwork.org/default.aspx?a=news&id=845| archive-date = May 11, 2012| archive-url = https://web.archive.org/web/20120511021937/http://www.diversalertnetwork.org/default.aspx?a=news&id=845| url-status = live}}

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:{{Cite web| title = Host-parasite Database| publisher = Natural History Museum| date = November 13, 2011| url = http://www.nhm.ac.uk/research-curation/research/projects/host-parasites/database/results.jsp?location=¶group=&showparasites=on¶species=&fmhostgenus=Contains&fmparagenus=Starts+with&showrefs=on&fmsubgroup=Starts+with&search=Search&groupby=parasite&pstatus=&showhosts=on¶genus=&fmparaspecies=Starts+with&subgroup=&showgrouping=on&fmhostspecies=Starts+with&hstate=&hostgenus=Dasyatis&hostspecies=kuhlii| access-date = November 13, 2011| archive-date = September 6, 2023| archive-url = https://web.archive.org/web/20230906151054/https://www.nhm.ac.uk/research-curation/scientific-resources/taxonomy-systematics/host-parasites/database/results.jsp?location=¶group=&showparasites=on¶species=&fmhostgenus=Contains&fmparagenus=Starts+with&showrefs=on&fmsubgroup=Starts+with&search=Search&groupby=parasite&pstatus=&showhosts=on¶genus=&fmparaspecies=Starts+with&subgroup=&showgrouping=on&fmhostspecies=Starts+with&hstate=&hostgenus=Dasyatis&hostspecies=kuhlii| url-status = live}}

Common Class	Group	Parasite
class="wikitable"
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 media

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|width=300px

|video1=[https://www.youtube.com/watch?v=UIif0dGWMt0 Blue spotted stingray swimming] YouTube

|video2=[https://www.youtube.com/watch?v=zeV2KFw6qKA Hand feeding a blue spotted stingray]YouTube

|video3=[http://video.nationalgeographic.com/video/player/nat-geo-wild/wild-all-videos/ngc-how-whales-eat-sharks.html How Whales Eat Sharks]{{dead link|date=January 2025|bot=medic}}{{cbignore|bot=medic}} 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.{{cite journal | url=https://doi.org/10.1016/j.foodchem.2018.07.206 | doi=10.1016/j.foodchem.2018.07.206 | title=Identification and characterization of antioxidant peptides from hydrolysate of blue-spotted stingray and their stability against thermal, pH and simulated gastrointestinal digestion treatments | year=2019 | last1=Wong | first1=Fai-Chu | last2=Xiao | first2=Jianbo | last3=Ong | first3=Michelle G-Ling | last4=Pang | first4=Mei-Jing | last5=Wong | first5=Shao-Jun | last6=Teh | first6=Lai-Kuan | last7=Chai | first7=Tsun-Thai | journal=Food Chemistry | volume=271 | pages=614–622 | pmid=30236723 | s2cid=52309495 | access-date=2022-01-13 | archive-date=2023-09-06 | archive-url=https://web.archive.org/web/20230906151055/https://www.sciencedirect.com/science/article/abs/pii/S0308814618313657?via%3Dihub | url-status=live }}