Clown Wedgefish

description

Description. Body relatively delicate; snout in front of eyes narrowly pointed to weakly bottle-shaped, angle of about 45 ° in holotype; lateral margin of anterior half of snout weakly concave, then becoming strongly convex forward of eye to origin of pectoral fin. Preorbital length about 3.5 in holotype (3.4 – 4.0 in all paratypes) times interorbital width; preoral length 3.3 (3.2 – 3.6) times mouth width. Disc width across pectoral-fin apices 77 % (73 – 79 % in adults and subadults exceeding 40 cm TL, 70 – 74 % in juveniles smaller than 40 cm TL) of disc length (from snout tip to pectoral-fin free rear tips). Head strongly depressed, disc thickness 1.1 (0.7 – 1.4) times in interorbital space; ventral head length 3.1 (2.8 – 3.2) times TL; surface between eyes and spiracles almost flat. Tail moderately depressed; in cross section, strongly rounded both dorsally and ventrally, angular laterally, tapering evenly from pelvic-fin insertions; precloacal length 85 % (84 – 105 %) of length of tail from anterior vent to caudal-fin tip; width of tail at first dorsal-fin insertions of holotype 1.8 (1.2 – 2.0) times interspiracular distance. Lateral keels of tail extended forward as a promine

A new species of wedgefish Rhynchobatus cooki (Rhinopristiformes, Rhinidae) from the Indo – West Pacific

diagnosis

Diagnosis. A dwarf species of the genus Rhynchobatus (adults to 81 cm TL) with the following combination of characters: a very long, narrowly pointed snout, preoral snout 21 – 25 % TL; eye small, length 5.1 – 6.6 in preorbital snout; interorbital space 3.2 – 4.0 in preorbital snout; mouth weakly bowed, with a strong indentation on upper jaw near symphysis and strong protuberance on lower jaw; tooth rows in upper jaw 32 – 39; two irregular rows of small rostral spines on distal third of snout, almost extending to snout tip but not distinctly paired; supraorbital spines small but well differentiated, discontinuous (present only on preorbit and beside spiracle); mid-dorsal spine row broken but well-developed in adults; only a few small scapular spines on shoulder (often obscure); origin of first dorsal fin slightly posterior to origin of pelvic-fin base; predorsal length 47 – 51 % TL; colour dark greyish green above (when fresh) with variable pattern of white spots (not arranged in rows), juveniles more densely covered with large white blotches; dark cruciate marking on interorbital but no black pectoral marking; anterior pectoral disc and sides of tail with a broad white margin; a fe

A new species of wedgefish Rhynchobatus cooki (Rhinopristiformes, Rhinidae) from the Indo – West Pacific

distribution

Distribution. Specimens obtained from the Jurong fish market (Singapore) and a Jakarta fish market (probably Muara Angke) (Indonesia). Also observed at Muara Angke fish market (Jakarta, Indonesia) in the early 1990 s. Fishers landing product at these markets operate widely across the Indo – Malay Archipelago so the providence of specimens are unknown. For example, fish landed at Jurong are unlikely to be from Singaporean waters, but may be from the South China, Java or Andaman Seas.

A new species of wedgefish Rhynchobatus cooki (Rhinopristiformes, Rhinidae) from the Indo – West Pacific

etymology

Etymology. Patronym proposed by one of us (LC) to honour the late Sid Cook, a pioneer in shark conservation who participated in surveys of chondrichthyan fishes in South-East Asia at the time specimens were collected. Vernacular: The name proposed here, Clown Wedgefish in recognition of its clown-like colour pattern, was coined by Lim Kok Peng (alias Kelvin) who participated in the collection of most of the types. Also referred to as the Roughnose Wedgefish (Compagno & Last, 1999). Comparisons. Shares with the much larger (to ~ 300 cm TL), Atlantic species Rhynchobatus luebberti, welldeveloped rostral spines, relatively small eyes, nearly straight tooth bands, pelvic fins with rounded apices, disc with a prominent white margin, and a cross-like marking on the interorbit (most obvious in young and subadults). Rhynchobatus luebberti differs from R. cooki sp. nov. in having a shorter, less hastate snout (preoral length 20 – 21 % TL vs. 21 – 25 % in R. cooki sp. nov.); combined lateral margin of head and anterior pectoral fin much less undulate in adults (particularly deeply concave behind eyes in R. cooki sp. nov.); rostral spines more numerous and concentrated on rostral ridges, exte

A new species of wedgefish Rhynchobatus cooki (Rhinopristiformes, Rhinidae) from the Indo – West Pacific