Sinobatis brevicauda
Weigmann & Stehmann, 2016
Shorttail Legskate
Classification: Elasmobranchii Rajiformes Anacanthobatidae
Reference of the original description
Sinobatis brevicauda n. sp., a new deep-water legskate (Rajiformes, Anacanthobatidae) and first generic record from the western Indian Ocean. Zootaxa, 4137(4), 478–500
Sinobatis brevicauda n. sp., a new deep-water legskate (Rajiformes, Anacanthobatidae) and first generic record from the western Indian Ocean. Zootaxa, 4137(4), 478–500
Description :
Citation: Sinobatis brevicauda Weigmann & Stehmann, 2016: In: Database of modern sharks, rays and chimaeras, www.shark-references.com, World Wide Web electronic publication, Version 11/2024
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Sinobatis brevicauda, presumably adult, female, paratype (ZMH 26159), 546mm TL; © Dr. Simon Weigmann, Elasmo-Lab, Elasmobranch Research Laboratory
Sinobatis brevicauda, presumably adult, female, paratype (ZMH 26159), 546mm TL; © Dr. Simon Weigmann, Elasmo-Lab, Elasmobranch Research Laboratory
Common names
Shorttail Legskate
Shorttail Legskate
Short Description
Original diagnosis after WEIGMANN & STEHMANN, 2016 [24300]: A large western Indian Ocean anacanthobatid species growing to about 591 mm TL, with an extremely depressed pear-shaped, broad and long disc (width 71–73% TL, length 76% TL), 0.9–1.0 times as wide as long and with rounded outer corners. Head (dorsal length 34% TL, ventral length 41% TL) and snout (preorbital length 28–29% TL, preoral length 30% TL, prenasal length 28% TL) long; snout angle 90–93°; snout terminally expanded as a rostral lobe that is 12–13% of preorbital snout length and with a short, thin rostral filament. Interorbital distance rather wide, 4% TL. Inner margin of posterior pelvic lobe fused to root of tail along most of its length with a short, pointed free tip. Tail very short, length from mid-vent to tail tip 35–36% TL and about half of body length from tip of rostral lobe to mid-vent; tail tapering from anterior part towards about mid-length of tail, but becoming slightly broader and flattened in posterior third through lateral keels, and tapering again towards tip from about 2 cm before tip. Caudal fin rudimentary with very short and low epichordal and without hypochordal lobe. Upper and lower surfaces of disc and tail entirely naked and without papillae. Upper surface pale grayishbrown, ventral side anteriorly whitish to level of lower jaw and interbranchially, posterior part of disc and underside of tail pale grayish-brown with irregular pale brown blotches at transition from white to brown, underside of posterior pelvic lobe medium grayish-brown, anterior lobes dark brown with an indistinct white blotch near the tip and a distinct white blotch at anterior origin. Upper jaw tooth rows 25–27, monospondylous vertebral centra 29, diplospondylous centra 102–112, total centra 131–141. Scapulocoracoid subrectangular, with rear corner sharply marked; moderately large oval anterior fenestra without anterior bridge, one very large oval postdorsal and at least three small postventral fenestrae. Pelvic girdle with massive ischiopubic bar with almost straight anterior and broad, shallow trapezoid posterior contour; prepelvic processes very long and slightly inclined outwards, their length from axis of pelvic girdle maximum width 77.5–90.9% of pelvic girdle maximum width and 4.9–5.6 times median thickness of ischiopubic bar. The new species differs from all other described anacanthobatids in the short tail, which also discriminates it from its morphologically closest congener, the allopatric Sinobatis bulbicauda. Sinobatis brevicauda n. sp. is further distinguished from the other anacanthobatid legskates in the western Indian Ocean, Anacanthobatis marmorata and Indobatis ori, by its large size and light coloration.
Original diagnosis after WEIGMANN & STEHMANN, 2016 [24300]: A large western Indian Ocean anacanthobatid species growing to about 591 mm TL, with an extremely depressed pear-shaped, broad and long disc (width 71–73% TL, length 76% TL), 0.9–1.0 times as wide as long and with rounded outer corners. Head (dorsal length 34% TL, ventral length 41% TL) and snout (preorbital length 28–29% TL, preoral length 30% TL, prenasal length 28% TL) long; snout angle 90–93°; snout terminally expanded as a rostral lobe that is 12–13% of preorbital snout length and with a short, thin rostral filament. Interorbital distance rather wide, 4% TL. Inner margin of posterior pelvic lobe fused to root of tail along most of its length with a short, pointed free tip. Tail very short, length from mid-vent to tail tip 35–36% TL and about half of body length from tip of rostral lobe to mid-vent; tail tapering from anterior part towards about mid-length of tail, but becoming slightly broader and flattened in posterior third through lateral keels, and tapering again towards tip from about 2 cm before tip. Caudal fin rudimentary with very short and low epichordal and without hypochordal lobe. Upper and lower surfaces of disc and tail entirely naked and without papillae. Upper surface pale grayishbrown, ventral side anteriorly whitish to level of lower jaw and interbranchially, posterior part of disc and underside of tail pale grayish-brown with irregular pale brown blotches at transition from white to brown, underside of posterior pelvic lobe medium grayish-brown, anterior lobes dark brown with an indistinct white blotch near the tip and a distinct white blotch at anterior origin. Upper jaw tooth rows 25–27, monospondylous vertebral centra 29, diplospondylous centra 102–112, total centra 131–141. Scapulocoracoid subrectangular, with rear corner sharply marked; moderately large oval anterior fenestra without anterior bridge, one very large oval postdorsal and at least three small postventral fenestrae. Pelvic girdle with massive ischiopubic bar with almost straight anterior and broad, shallow trapezoid posterior contour; prepelvic processes very long and slightly inclined outwards, their length from axis of pelvic girdle maximum width 77.5–90.9% of pelvic girdle maximum width and 4.9–5.6 times median thickness of ischiopubic bar. The new species differs from all other described anacanthobatids in the short tail, which also discriminates it from its morphologically closest congener, the allopatric Sinobatis bulbicauda. Sinobatis brevicauda n. sp. is further distinguished from the other anacanthobatid legskates in the western Indian Ocean, Anacanthobatis marmorata and Indobatis ori, by its large size and light coloration.
Dentition
27 (25) tooth rows in upper and 26 (25) in lower jaws, set in quincunx pavement pattern; individual tooth with low, broadly ovoid base, flat crown, and with very short and stout, conical cusp at inner edge [24300]
27 (25) tooth rows in upper and 26 (25) in lower jaws, set in quincunx pavement pattern; individual tooth with low, broadly ovoid base, flat crown, and with very short and stout, conical cusp at inner edge [24300]
Remarks
shark-references Species-ID=14610;
shark-references Species-ID=14610;