Taiwanese Wedgefish

Rhynchobatus immaculatus Last, Ho & Chen 2013

Rhynchobatus immaculatus Last, Ho & Chen, 2013 [this issue] Type locality: Keelung, Taiwan The two samples of Rhynchobatus immaculatus n. sp. included in our analysis represent a distinct lineage, sister to a clade comprising several Rhynchobatus species from Malaysia and Australia, i.e. R. australiae (GN2996), R. cf. laevis (GN2065), R. laevis (GN3004) and R. palpebratus (GN2044) (Supplementary Material 1). This species was determined as a new and previously undescribed species during this study based on both, the molecular results and morphological information.

A DNA sequence-based identification checklist for Taiwanese chondrichthyans

description

Description. Body relatively robust; snout in front of eyes bluntly angular to obtusely wedge-shaped, angle about 50 ° in holotype (52 – 53 ° in paratypes). Lateral margin of snout slightly convex beside orbit, otherwise almost straight. Preorbital length 3.3 in holotype (3.3 – 3.4 in paratypes) times interorbital width. Preoral length 3.4 (3.0 – 3.3) times mouth width. Disc width across pectoral-fin apices 75 % (75 – 77 %) of disc length from snout tip to pectoral-fin free rear tips. Head strongly depressed, trowel-shaped, disc thickness 1.5 (1.6 – 1.7) times in interorbital space; ventral head length 3.2 (3.2 – 3.4) times in total length; surface between eyes and spiracles almost flat. Precloacal length 85 % (86 – 88 %) of length of tail from anterior vent to caudal-fin tip. Tail moderately depressed; in cross section, arched dorsally, almost flat ventrally, angular ventrolaterally at lateral keels, tapering evenly from pelvic-fin insertions. Width of tail at first dorsal-fin insertions of holotype 1.8 (1.6 – 1.9) times interspiracular distance. Lateral keels extended forward as a thickened angular edge along precaudal tail, reaching forward to below posterior half of first-dorsa

A new species of wedgefish, Rhynchobatus immaculatus (Chondrichthyes, Rhynchobatidae), from Taiwan

description

Non-types. 6 specimens: ASIZP 63513, immature male 408 mm TL, Ao-di, Taipei county, northeastern Taiwan, ca. 25 ° 03 ’ N, 121 ° 56 ’ E, 17 Jul. 2001, coll. Z. - H. Wu; ASIZP 66972, female 835 mm TL, Da-xi, northeastern Taiwan, 5 Feb 2007; NMMB – P 16225, immature male 744 mm TL, Da-xi, Yilan County, northeastern Taiwan, ca. 24 ° 56 ’ N, 121 ° 54 ’ E, 13 Mar 2012, purchased from market by P. Last; NMMB – P 16224, immature female 915 mm TL, Wu-chi fish market, Taichung, Taiwan Strait, western Taiwan, ca. 24 ° 18 ’ N, 120 ° 29 ’ E, 10 Apr 2012, purchased from the market by H. Ho; NMMB – P 15684, immature male 992 mm TL, collected together with CSIRO H 7418 – 01; NMMB – P 15661, immature male 591 mm TL, Wu-chi fish market, Taichung, Taiwan Strait, western Taiwan, ca. 24 ° 18 ’ N, 120 ° 29 ’ E, 11 Sep 2011, purchased from the market by H. Ho.

A new species of wedgefish, Rhynchobatus immaculatus (Chondrichthyes, Rhynchobatidae), from Taiwan

diagnosis

Diagnosis. A medium-sized species of the genus Rhynchobatus with the following combination of characters: a broad, wedge-shaped snout; preoral snout 19 – 21 % TL; eye small, length 4.1 – 4.5 in preorbital snout; interorbital space 2.6 – 2.9 in preorbital snout; tooth rows about 48; spines absent from snout; supraorbital spines small, well differentiated, extending from preorbit to beyond end of spiracle; predorsal spines relatively well developed; two disjunct rows of 6 – 9 small scapular spines on each side of disc; predorsal space 48 – 49 % of total length; origin of first dorsal fin well behind origin of pelvic-fin bases; dark greenish brown dorsally with a few white spots scattered on pectoral disc; black pectoral marking absent; prominent row of white spots commencing just forward of a single white spot (above pelvic-fin origin) and coalescing posteriorly to form a white mid-lateral line on tail; orbital membrane white with dark bar over eye; no alternating light and dark markings on interorbital space; total pectoralfin radials 65 – 68; vertebrae with 28 – 30 monospondylous precaudal centra, 124 – 131 precaudal free centra, 38 – 42 diplospondylous caudal (free) centra, 165 –

A new species of wedgefish, Rhynchobatus immaculatus (Chondrichthyes, Rhynchobatidae), from Taiwan