Banded stingaree
Encyclopedia
The crossback stingaree or banded stingaree (Urolophus cruciatus) 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
.. This bottom-dwelling fish generally inhabits sand and reef habitat
s deeper than 100 m (328.1 ft) off Victoria, and muddy habitats in shallow bay
s and estuaries off Tasmania. Befitting its name, the crossback stingaree has a distinctive dark pattern on its back, consisting of a midline stripe that is crossed by three transverse bars. It has an oval pectoral fin disc with a blunt snout and a skirt-shaped curtain of skin between the nostrils. Its tail is short with no skin fold along the sides, and a deep, leaf-shaped caudal fin. The youngest rays may have a small dorsal fin
in front of the stinging tail spine. This species reaches 50 cm (19.7 in) in length.
During the day, the crossback stingaree can usually be found resting partially or completely buried on the sea floor. Its diet consists primarily of isopods and other small crustacean
s, and to a lesser extent polychaete worms. It is aplacental viviparous, with the developing embryo
s sustained to term by histotroph ("uterine milk") produced by the mother. Females bear litters of up to four pups every other year, after a gestation period
of at least six months. This species is closely related to, and may hybridize with, the yellowback stingaree
(U. sufflavus). The venom
ous sting of the crossback stingaree is potentially injurious to humans. This common species is seldom caught by commercial fisheries
other than in the northernmost extent of its range. Thus, its population is largely secure and the International Union for Conservation of Nature (IUCN) has listed it under Least Concern
.
Bernard Lacépède originally described the crossback stingaree as Raja cruciata, in an 1804 volume of the scientific journal
Annales du Muséum d'Histoire Naturelle Paris. The specific epithet means "cross-like" in Latin
, referring to the distinctive markings on its back. The origin of the type specimen was given simply as New Holland
(Australia). In their 1938–41 Systematische Beschreibung der Plagiostomen, German biologists Johannes Müller
and Jakob Henle
placed this species in the newly created genus Urolophus.
The Victoria
n and Tasmania
n subpopulations of the crossback stingaree differ markedly in habitat preferences and merit further taxonomic investigation, according to the International Union for Conservation of Nature (IUCN). This ray is closely related to the yellowback stingaree
(U. sufflavus). In addition to morphological
similarities, the two may also hybridize (see below) and, in a 2007 study of 388 fishes by Robert Ward and Bronwyn Holmes, were the only species that could not be distinguished on the basis of their cytochrome c
gene sequences, attesting to a close evolutionary relationship.
in New South Wales
, and as far west as Beachport
in South Australia
. Bottom-dwelling in nature, this species has been reported from the intertidal zone
to a depth of 210 m (689 ft) on the upper continental slope. Rays of the Victorian subpopulation prefer sandy flats and rocky reef
s and are seldom seen in less than 25 m (82 ft) of water, occurring most commonly at depths greater than 100 m (328.1 ft). By contrast, rays of the Tasmanian subpopulation are usually found over muddy bottoms in very shallow bay
s and large estuaries, occasionally penetrating into brackish water
.
s, which have rounded to angular posterior rims. The outer rim of each nostril may form a small knob at the back. Between the nostrils is a skirt-shaped curtain of skin with a deeply fringed posterior margin. The mouth is small and strongly arched, containing 3–6 papillae (nipple-like structures) on the floor and an additional patch of papillae is present on the outside of the lower jaw. Both upper and lower teeth are small with roughly oval bases, and are arranged in a quincunx
pattern. The five pairs of gill slit
s are short. The pelvic fins are small, with rounded margins.
The rather short tail measures 63–84% of the disc's length and is a flattened oval in cross-section, without lateral skin folds. A single serrated, stinging spine is positioned on top, about halfway along the tail's length. In newborns, the sting is preceded by a small dorsal fin
; the fin is lost with age, though it may be evidenced by a small ridge or scar. At the end of the tail is a very short, deep, leaf-shaped caudal fin. The skin is entirely devoid of dermal denticles. The crossback stingaree is grayish to yellowish brown above with a pattern of dark markings, including a stripe running along the midline and crossed by three transverse bars: one near the eyes, one over the gill region, and one over the center of the disc. The pattern is strongest in rays from the southern portion of its range. A few dark brown or black individuals have been recorded. The underside is off-white, sometimes becoming slightly darker at the disc margin. The caudal fin is more grayish than the body, and there may be dusky blotches on the tail. This species attains a maximum known length of 50 cm (19.7 in). Females generally grow larger than males.
Generally nocturnal, the crossback stingaree spends long stretches of the day lying motionless on the sea floor, partially or completely buried in sediment. It has been known to form groups of varying size, sometimes mixing with other stingaree species. This ray is a generalist
predator that forages for small organisms on or buried in the bottom. Off Victoria, over three-quarters of prey consumed are crustacean
s, of which isopods (particularly Natalolana woodjonesi and N. wowine) comprise the majority and amphipods and decapod
s the remainder. Polychaete worms are also eaten in significant quantities, while priapulids and the burrowing squid
Euprymna tasmanica are infrequently taken. Young rays under 30 cm (11.8 in) across feed mainly on smaller isopods, amphipods, and shrimp
s; with age a progressively greater diversity of larger prey, such as penaeid prawn
s, priapulids, and polychaetes, are incorporated into its diet.
The broadnose sevengill shark
(Notorynchus cepedianus) is known to prey on the crossback stingaree. When threatened, this ray raises its tail warningly above its body in a scorpion
-like fashion. Parasites documented from this species include a tapeworm in the genus Acanthobothrium, and the monogenea
n Calicotyle urolophi. Like other stingrays, the crossback stingaree is aplacental viviparous: when the developing embryo
s exhaust their supply of yolk, their mother provisions them with nutrient
-rich histotroph ("uterine milk") through specialized extensions of the uterine epithelium
called "trophonemata". Females produce litters of 1–4 pups every other year. Embryonic development proceeds rapidly over a six-month period, though the total gestation period
may be much longer if there is a period of dormancy for the eggs after fertilization, as has been reported in other stingarees. Off Tasmania, large estuaries such as at the mouth of the Derwent River
serve as nursery areas.
Different authors have variously reported the birth length at between 10 and 15 cm (3.9 and 5.9 in), and the maturation
length at between 20 and 32 cm (7.9 and 12.6 in), with females usually maturing at a slightly larger size than males. This range of sizes may reflect life history differences in crossback stingarees across different parts of its range. Both sexes mature at around six years of age, and can live to at least 11 years. The crossback stingaree may hybridize naturally with the closely related yellowback stingaree off southern New South Wales, where the distributions of the two species overlap and apparent hybrid offspring with intermediate color patterns have been found. If true, this would represent one of the few known cases of hybridization among cartilaginous fishes.
ous sting, that may require surgical intervention if the serrated tip of the sting breaks off inside the wound. The base of its tail is highly flexible, allowing it to strike a person touching any part of its body. In the 19th century, the hazard posed by this species led to persecution by fishery
workers in the form of "spiking", in which a metal spike is used to pierce the ray's cranium and remove it from the net. The IUCN has listed the crossback stingaree under Least Concern
, as it is exposed to minimal fishing activity in the Bass Strait
and off western Tasmania, which constitute most of its distribution. The impact of Tasmanian inshore fisheries is unquantified but unlikely to be severe. Off New South Wales, it is caught incidentally
in otter trawls and gillnet
s used by the Southern and Eastern Scalefish and Shark Fishery (SESSF). Captured rays likely experience high mortality, and also tend to abort any unborn young. While the SESSF has caused an overall decline in deepwater stingarees within its area of operations, it only affects a small portion of this species' range.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of stingray
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
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Urolophidae. It is endemic to southeastern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, mainly off Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
and Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
but also marginally 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...
and South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
.. This bottom-dwelling fish generally inhabits sand and reef 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 deeper than 100 m (328.1 ft) off Victoria, and muddy habitats in shallow bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
s and estuaries off Tasmania. Befitting its name, the crossback stingaree has a distinctive dark pattern on its back, consisting of a midline stripe that is crossed by three transverse bars. It has an oval pectoral fin disc with a blunt snout and a skirt-shaped curtain of skin between the nostrils. Its tail is short with no skin fold along the sides, and a deep, leaf-shaped caudal fin. The youngest rays may have a small 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...
in front of the stinging tail spine. This species reaches 50 cm (19.7 in) in length.
During the day, the crossback stingaree can usually be found resting partially or completely buried on the sea floor. Its diet consists primarily of isopods and other small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, and to a lesser extent polychaete worms. It is aplacental viviparous, with the developing embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s sustained to term by histotroph ("uterine milk") produced by the mother. Females bear litters of up to four pups every other year, after a gestation period
Gestation period
For mammals the gestation period is the time in which a fetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.-Duration:...
of at least six months. This species is closely related to, and may hybridize with, the yellowback stingaree
Yellowback stingaree
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...
(U. sufflavus). The venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
ous sting of the crossback stingaree is potentially injurious to humans. This common species is seldom caught by 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...
other than in the northernmost extent of its range. Thus, its population is largely secure and the International Union for Conservation of Nature (IUCN) has listed it under Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
.
Taxonomy
French naturalistNaturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
Bernard Lacépède originally described the crossback stingaree as Raja cruciata, in an 1804 volume of the scientific journal
Scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of scientific journals in publication, and many more have been published at various points in the past...
Annales du Muséum d'Histoire Naturelle Paris. The specific epithet means "cross-like" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, referring to the distinctive markings on its back. The origin of the type specimen was given simply as New Holland
New Holland (Australia)
New Holland is a historic name for the island continent of Australia. The name was first applied to Australia in 1644 by the Dutch seafarer Abel Tasman as Nova Hollandia, naming it after the Dutch province of Holland, and remained in use for 180 years....
(Australia). In their 1938–41 Systematische Beschreibung der Plagiostomen, German biologists Johannes Müller
Johannes Peter Müller
Johannes Peter Müller , was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge.-Early years and education:...
and Jakob Henle
Friedrich Gustav Jakob Henle
Friedrich Gustav Jakob Henle was a German physician, pathologist and anatomist. He is credited with the discovery of the loop of Henle in the kidney. His essay "On Miasma and Contagia" was an early argument for the germ theory of disease...
placed this species in the newly created genus Urolophus.
The Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
n and Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
n subpopulations of the crossback stingaree differ markedly in habitat preferences and merit further taxonomic investigation, according to the International Union for Conservation of Nature (IUCN). This ray is closely related to the yellowback stingaree
Yellowback stingaree
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...
(U. sufflavus). In addition to morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
similarities, the two may also hybridize (see below) and, in a 2007 study of 388 fishes by Robert Ward and Bronwyn Holmes, were the only species 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.
Distribution and habitat
The distribution of the crossback stingaree mainly encompasses the coastal waters of Victoria and Tasmania, where it is quite abundant; it ranges as far east as Jervis BayJervis Bay
Jervis Bay is a large bay bounded by the state of New South Wales, the Jervis Bay Territory, and a detached enclave of the Australian Capital Territory. HMAS Creswell is located between Jervis Bay Village and Greenpatch in the Jervis Bay Territory.-History:...
in 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...
, and as far west as Beachport
Beachport, South Australia
Beachport is a small coastal town 379 kilometres south-east of Adelaide, South Australia, located in the Wattle Range Council. Known for its 772 metre long jetty , Beachport is located on the northern end of Rivoli Bay...
in South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
. Bottom-dwelling in nature, this species has been reported from the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
to a depth of 210 m (689 ft) on the upper continental slope. Rays of the Victorian subpopulation prefer sandy flats and rocky reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s and are seldom seen in less than 25 m (82 ft) of water, occurring most commonly at depths greater than 100 m (328.1 ft). By contrast, rays of the Tasmanian subpopulation are usually found over muddy bottoms in very shallow bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
s and large estuaries, occasionally penetrating into brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
.
Description
The crossback stingaree's pectoral fin disc is slightly wider than long and oval in shape, with the anterior margins nearly straight and converging at a very obtuse angle. The snout is fleshy and blunt, generally not protruding from the disc. The eyes are small and immediately followed by teardrop-shaped spiracleSpiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
s, which have rounded to angular posterior rims. The outer rim of each nostril may form a small knob at the back. Between the nostrils is a skirt-shaped curtain of skin with a deeply fringed posterior margin. The mouth is small and strongly arched, containing 3–6 papillae (nipple-like structures) on the floor and an additional patch of papillae is present on the outside of the lower jaw. Both upper and lower teeth are small with roughly oval bases, and are arranged in a quincunx
Quincunx
A quincunx is a geometric pattern consisting of five points arranged in a cross, that is five coplanar points, four of them forming a square or rectangle and a fifth at its center...
pattern. The five pairs of gill slit
Gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of Cartilaginous fish such as sharks, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...
s are short. The pelvic fins are small, with rounded margins.
The rather short tail measures 63–84% of the disc's length and is a flattened oval in cross-section, without lateral skin folds. A single serrated, stinging spine is positioned on top, about halfway along the tail's length. In newborns, the sting is preceded by a small 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...
; the fin is lost with age, though it may be evidenced by a small ridge or scar. At the end of the tail is a very short, deep, leaf-shaped caudal fin. The skin is entirely devoid of dermal denticles. The crossback stingaree is grayish to yellowish brown above with a pattern of dark markings, including a stripe running along the midline and crossed by three transverse bars: one near the eyes, one over the gill region, and one over the center of the disc. The pattern is strongest in rays from the southern portion of its range. A few dark brown or black individuals have been recorded. The underside is off-white, sometimes becoming slightly darker at the disc margin. The caudal fin is more grayish than the body, and there may be dusky blotches on the tail. This species attains a maximum known length of 50 cm (19.7 in). Females generally grow larger than males.
Biology and ecology
Generalist and specialist species
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources . A specialist species can only thrive in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either...
predator that forages for small organisms on or buried in the bottom. Off Victoria, over three-quarters of prey consumed are crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, of which isopods (particularly Natalolana woodjonesi and N. wowine) comprise the majority and amphipods and decapod
Decapoda
The decapods or Decapoda are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crayfish, crabs, lobsters, prawns and shrimp. Most decapods are scavengers. It is estimated that the order contains nearly 15,000 species in around 2,700 genera, with...
s the remainder. Polychaete worms are also eaten in significant quantities, while priapulids and the burrowing squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
Euprymna tasmanica are infrequently taken. Young rays under 30 cm (11.8 in) across feed mainly on smaller isopods, amphipods, and shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
s; with age a progressively greater diversity of larger prey, such as penaeid prawn
Penaeidae
Penaeidae is a family of prawns, although they are often referred to as penaeid shrimp. It contains many species of economic importance, such as the tiger prawn , whiteleg shrimp, Atlantic white shrimp and Indian prawn. Many prawns are the subject of commercial fishery, and farming, both in marine...
s, priapulids, and polychaetes, are incorporated into its diet.
The broadnose sevengill shark
Broadnose sevengill shark
The broadnose sevengill shark is the only extant member of the genus Notorynchus, in the family Hexanchidae. It is recognizable because of its seven gill slits, while most shark species have five gill slits, with the exception of the members of the order Hexanchiformes and the sixgill sawshark.The...
(Notorynchus cepedianus) is known to prey on the crossback stingaree. When threatened, this ray raises its tail warningly above its body in a scorpion
Scorpion
Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger...
-like fashion. Parasites documented from this species include a tapeworm in the genus Acanthobothrium, and the monogenea
Monogenea
Monogenea are a group of largely ectoparasitic members of the flatworm phylum Platyhelminthes, class Monogenea.-Characteristics:Monogenea are very small parasitic flatworms mainly found on skin or gills of fish....
n Calicotyle urolophi. Like other stingrays, the crossback stingaree is aplacental viviparous: when the developing embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s exhaust their supply of yolk, their mother provisions them with nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
-rich histotroph ("uterine milk") through specialized extensions of the uterine epithelium
Epithelium
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...
called "trophonemata". Females produce litters of 1–4 pups every other year. Embryonic development proceeds rapidly over a six-month period, though the total gestation period
Gestation period
For mammals the gestation period is the time in which a fetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.-Duration:...
may be much longer if there is a period of dormancy for the eggs after fertilization, as has been reported in other stingarees. Off Tasmania, large estuaries such as at the mouth of the Derwent River
Derwent River (Tasmania)
The Derwent is a river in Tasmania, Australia. It was named after the River Derwent, Cumbria by British Commodore John Hayes who explored it in 1793. The name is Brythonic Celtic for "valley thick with oaks"....
serve as nursery areas.
Different authors have variously reported the birth length at between 10 and 15 cm (3.9 and 5.9 in), and the maturation
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
length at between 20 and 32 cm (7.9 and 12.6 in), with females usually maturing at a slightly larger size than males. This range of sizes may reflect life history differences in crossback stingarees across different parts of its range. Both sexes mature at around six years of age, and can live to at least 11 years. The crossback stingaree may hybridize naturally with the closely related yellowback stingaree off southern New South Wales, where the distributions of the two species overlap and apparent hybrid offspring with intermediate color patterns have been found. If true, this would represent one of the few known cases of hybridization among cartilaginous fishes.
Human interactions
The crossback stingaree can inflict an excruciating injury on an unwary human with its venomVenom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
ous sting, that may require surgical intervention if the serrated tip of the sting breaks off inside the wound. The base of its tail is highly flexible, allowing it to strike a person touching any part of its body. In the 19th century, the hazard posed by this species led to persecution by fishery
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
workers in the form of "spiking", in which a metal spike is used to pierce the ray's cranium and remove it from the net. The IUCN has listed the crossback stingaree under Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
, as it is exposed to minimal fishing activity in the Bass Strait
Bass Strait
Bass Strait is a sea strait separating Tasmania from the south of the Australian mainland, specifically the state of Victoria.-Extent:The International Hydrographic Organization defines the limits of the Bass Strait as follows:...
and off western Tasmania, which constitute most of its distribution. The impact of Tasmanian inshore fisheries is unquantified but unlikely to be severe. Off New South Wales, it is caught incidentally
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 used by the Southern and Eastern Scalefish and Shark Fishery (SESSF). Captured rays likely experience high mortality, and also tend to abort any unborn young. While the SESSF has caused an overall decline in deepwater stingarees within its area of operations, it only affects a small portion of this species' range.