Yellowback stingaree
Encyclopedia
The yellowback stingaree, Urolophus sufflavus, is a locally abundant but little-known species of stingray
in the family Urolophidae. It is almost endemic to New South Wales
, with a range from Green Cape
northward, extending only barely into Queensland
(Stradbroke Island
). It inhabits soft-substrate habitat
s and has been reported from depths of 45-300 meters (150-980 ft), though it is most common on the outer continental shelf
at depths of 100-160 meters (330-520 ft).
This species attains a maximum length of 42 cm (17 in). It has a flattened pectoral fin disk about as wide as long, with rounded corners and straight anterior margins. There is a skirt
-like nasal curtain in front of the mouth
, without lateral lobes. The tail is short and stout, measuring 64-76% the length of the disk and bearing a serrated spine. The tail ends in a small caudal fin; there are no dorsal fin
s or lateral folds. The skin is devoid of dermal denticles. The coloration is uniformly yellowish above, sometimes with an ill-defined brown stripe running down the back.
The yellowback stingaree is likely ovoviviparous with low fecundity
, as in other stingarees. Males mature at a length of 23 cm (9 in). This species shares the southern extent of its range with the banded stingaree
(U. cruciatus). The two species apparently hybridize, highly unusual for cartilaginous fish, and produce offspring that are intermediate in color pattern. In a 2007 study of 388 fishes, these two species were the only two that could not be distinguished on the basis of their cytochrome c
gene sequences, attesting to a close evolutionary relationship.
Almost the entire range of the yellowback stingaree is under pressure from Australian Commonwealth and State-managed commercial fisheries
. This species is caught as bycatch
in otter trawls and gillnet
s; though it is generally discarded, survival post-capture is believed to be low, and in addition stingarees tend to abort gestating young if captured and handled. From 1966-67 to 1996-97, the capture rate of stingarees in trawl surveys on the New South Wales upper slope, including the yellowback stingaree, declined by some 65%. Trawl surveys off Sydney
found a similar decline of 45%. These negative trends and this species' restricted distribution has led it to be assessed as Vulnerable
by the World Conservation Union
.
Stingray
The stingrays are a group of rays, which are cartilaginous fishes related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes, and consist of eight families: Hexatrygonidae , Plesiobatidae , Urolophidae , Urotrygonidae , Dasyatidae , Potamotrygonidae The...
in the family Urolophidae. It is almost endemic to New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, with a range from Green Cape
Green Cape
Green Cape is a headland or cape on the far south coast of New South Wales. It is located at 37° 15' S 150° 03' E, within Ben Boyd National Park, south of Eden, New South Wales...
northward, extending only barely into Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
(Stradbroke Island
Stradbroke Island
Stradbroke Island, also known as Minjerribah, was a large sand island that formed much of the eastern side of Moreton Bay near Brisbane, Queensland until the late 19th century...
). It inhabits soft-substrate habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s and has been reported from depths of 45-300 meters (150-980 ft), though it is most common on the outer continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...
at depths of 100-160 meters (330-520 ft).
This species attains a maximum length of 42 cm (17 in). It has a flattened pectoral fin disk about as wide as long, with rounded corners and straight anterior margins. There is a skirt
Skirt
A skirt is a tube- or cone-shaped garment that hangs from the waist and covers all or part of the legs.In the western world, skirts are usually considered women's clothing. However, there are exceptions...
-like nasal curtain in front of the mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
, without lateral lobes. The tail is short and stout, measuring 64-76% the length of the disk and bearing a serrated spine. The tail ends in a small caudal fin; there are no dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s or lateral folds. The skin is devoid of dermal denticles. The coloration is uniformly yellowish above, sometimes with an ill-defined brown stripe running down the back.
The yellowback stingaree is likely ovoviviparous with low fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
, as in other stingarees. Males mature at a length of 23 cm (9 in). This species shares the southern extent of its range with the banded stingaree
Banded stingaree
The crossback stingaree or banded stingaree is a species of stingray in the family Urolophidae. It is endemic to southeastern Australia, mainly off Victoria and Tasmania but also marginally to New South Wales and South Australia....
(U. cruciatus). The two species apparently hybridize, highly unusual for cartilaginous fish, and produce offspring that are intermediate in color pattern. In a 2007 study of 388 fishes, these two species were the only two that could not be distinguished on the basis of their cytochrome c
Cytochrome c
The Cytochrome complex, or cyt c is a small heme protein found loosely associated with the inner membrane of the mitochondrion. It belongs to the cytochrome c family of proteins. Cytochrome c is a highly soluble protein, unlike other cytochromes, with a solubility of about 100 g/L and is an...
gene sequences, attesting to a close evolutionary relationship.
Almost the entire range of the yellowback stingaree is under pressure from Australian Commonwealth and State-managed commercial fisheries
Commercial fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions...
. This species is caught as bycatch
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
in otter trawls and gillnet
Gillnet
Gillnetting is a common fishing method used by commercial and artisanal fishermen of all the oceans and in some freshwater and estuary areas. The gillnet also is used by fisheries scientists to monitor fish populations. Because gillnets can be so effective their use is closely monitored and...
s; though it is generally discarded, survival post-capture is believed to be low, and in addition stingarees tend to abort gestating young if captured and handled. From 1966-67 to 1996-97, the capture rate of stingarees in trawl surveys on the New South Wales upper slope, including the yellowback stingaree, declined by some 65%. Trawl surveys off Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
found a similar decline of 45%. These negative trends and this species' restricted distribution has led it to be assessed as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
by the World Conservation Union
World Conservation Union
The International Union for Conservation of Nature and Natural Resources is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." The organization publishes the IUCN Red List, compiling information from a network of...
.