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Black-spotted whipray
The black-spotted whipray (''Himantura astra'') is a species of stingray in the family Dasyatidae, found in coastal waters off southern New Guinea and northern Australia. Long thought to be a variant of the related brown whipray (''H. toshi''), this species has an angular, diamond-shaped pectoral fin disc and a whip-like tail without fin folds. It is characterized by its dorsal color pattern, which consists of a variably extensive covering of small, close-set dark, and sometimes also white, spots on a grayish brown background. In addition, the tail has alternating light and dark saddles past the stinging spine. This species reaches a maximum recorded width of .
Crustaceans are the main type of food consumed by the black-spotted whipray. It is aplacental viviparous, with females gestating 1–3 young at a time, supplying them with histotroph ("uterine milk"). Most of the black-spotted whipray's range lies within Australian waters, where it faces minimal conservation threats since the widespread deployment of bycatch-reducing measures on commercial trawlers. It is caught in small numbers for meat, skin, and cartilage by Indonesian fishers, as well as by prawn seine fishers off Papua New Guinea. A 2004 assessment of the brown whipray by the International Union for Conservation of Nature (IUCN), which also included data on the black-spotted whipray, listed them under Least Concern.
==Taxonomy==
The black-spotted whipray was traditionally thought to be the same species as the brown whipray (''H. toshi'').〔 In 1994, Commonwealth Scientific and Industrial Research Organisation (CSIRO) researchers Peter Last and John Stevens tentatively identified a spotted variant of ''H. toshi'' as "''Himantura'' sp. A". However, it was not until more specimens became available for study in the mid-2000s that the black-spotted whipray was confirmed as distinct, albeit closely related, species to ''H. toshi''. Last, Mabel Manjaji-Matsumoto, and John Pogonoski formally described it in a 2008 CSIRO publication, giving it the specific epithet ''astra'' after the Latin ''astrum'' ("constellation"). The type specimen is an adult male across, collected from the Gulf of Carpentaria. Like ''T. toshi'', this species belongs to the 'uarnak' species complex, which also contains ''H. fai'', ''H. gerrardi'', ''H. jenkinsii'', ''H. leoparda'', ''H. uarnak'', and ''H. undulata''. Other common names for the black-spotted whipray include coachwhip ray, Tosh's longtail ray, and wulura.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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