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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 habitats deeper than off Victoria, and muddy habitats in shallow bays 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 in length. During the day the crossback stingaree is usually inactive and can be found partially or completely buried in sand on the sea floor. It is a carnivore and adults forage for crustaceans, polychaete worms and other small invertebrates on the seafloor.〔 Juveniles feed on smaller crustaceans such as isopods, amphipods and shrimps. The species is aplacental viviparous, with the developing embryos 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 venomous 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. ==Taxonomy== French naturalist 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 1838–41 ''Systematische Beschreibung der Plagiostomen'', German biologists Johannes Müller and Jakob Henle placed this species in the newly created genus ''Urolophus''. The Victorian and Tasmanian 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.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Crossback stingaree」の詳細全文を読む スポンサード リンク
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