Rhinobatos whitei Last, Corrigan & Naylor, 2014, sp. nov.
Creators: name: Last, Peter R.
name: Corrigan, Shannon
name: Naylor, Gavin
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Rajiformes
Rhinobatidae
Rhinobatos
Rhinobatos whitei

description: Rhinobatos whitei sp. nov.
[English Name: Philippine Guitarfish] (Figs 1–8, Tab. 1)
Rhinobatos schlegelii: Casto de Elera, 1895, 619; Manila, Luzon. Fowler, 1941, 308; listing of Casto de Elera’s record without new material. Compagno & Last, 1999, 1429. Western Central Pacific, Philippines (misidentifications)? Rhinobatos cf. schlegelii Müller & Henle, 1841: Compagno et al., 2005.
Holotype. PNM 15189 (formerly SUML F1086 and JPAG 079), adolescent male 597 mm TL, Dipolog City Public Market, collected J.A. Gaudiano, 10 April 1999.
Paratypes. 10 specimens, Suba, Pasil and Pasil Fish Port I, Cebu City; Dipolog City Public Market; Palapala Fish Port, Bacolod City; Palapala Fish Port, Cadiz City; Punta Miray, Baliangao; Silliman Beach, Dumaguete City, PNM 10318 (formerly SUML JPAG 277), female, 620 mm TL, 6 April 2000; CSIRO H 7542–01 (formerly SUML JPAG 300), mature male, 641 mm TL, 10 April 2000; CSIRO H 7542–02 (formerly SUML JPAG 301), female, 494 mm TL, 10 April 2000; CSIRO H 7542–03 (formerly SUML JPAG 306, mature male, 556 mm TL, 10 April 2000; CSIRO H 7542–04 (formerly SUML JPAG 308), mature male, 636 mm TL, 10 April 2000; SUML JPAG 309, immature male, 471 mm TL, 10 April 2000; CSIRO H 7542–05 (formerly SUML JPAG 310), mature male, 617 mm TL, April 10, 2000; SUML BRU 144, immature male, 317 mm TL, 28 March 2000; SUML MMLM 0 0 1, female, 764 mm TL, 1 March 1999; SUML F1 (formerly MMLM 012), female, 686 mm TL, 1 April 1999.
Other material. 11 specimens. SUML RSE 0 0 5, mature male, 705 mm TL, 4 March 1999; SUML JPAG 047a, male, 556 mm TL, 21 March 1999; SUML JPAG 278, female, 690 mm TL, 6 April 2000; SUML JPAG 307, immature male, 497 mm TL, 10 April 2000; SUML JPAG 311, female, 473 mm TL, 10 April 2000; SUML JPAG 0 43, mature male, 643 mm TL, 21 March 1999; SUML JPAG 0 45, female, 661 mm TL, 21 March 1999; SUML BRU 0 71, female, 820 mm TL, 15 April 1999; SUML BRU 0 72, female, 820 mm TL, 15 April 1999; SUML BRU 0 73, mature male, 720 mm TL, 15 April 1999; SUML BRU 0 74, female, 844 mm TL, 15 April 1999.
Diagnosis. A species of the genus Rhinobatos distinguished by the following combination of adult characters: wedge-shaped disc with an moderately concave anterior snout margin, width 31–35% TL, disc length 1.3–1.4 times width; snout length 3.0–3.4 times interspiracular distance, 3.9–5.2 times interorbital width; medium-sized orbit, 1.4–1.7 times spiracle length; weakly oblique nostrils, their length 1.3–1.6 times internarial distance; preoral length 6.8–7.8 times internarial distance; anterior nasal flaps penetrating slightly into internarial space but well separated at their insertion; posterior nasal flaps broad; large spiracles with two folds, outermost fold distinctly longer than inner fold; ridges of rostral cartilage almost parallel, converging slightly anteriorly but not constricted medially; anterior cartilage subtriangular; distance between fifth gill slits 3.0–3.4 times in ventral head length; prebranchial sensory pore patch obvious, extending to just behind first gill slit; postscapular sensory canal obvious, with exposed lateral pores, grooved; thorn patches on supraorbit, nuchal and scapular regions, and dorsal midline rudimentary, not conspicuous; pelvic-fin inner margin longer than its base in males, subequal in females; interdorsal distance 2.6–3.2 times length of first dorsal-fin base; dorsal caudal margin 2.1–2.6 times preventral margin; upper jaw with ca. 65–92 tooth rows; 173–179 post-synarcual centra; 50–53 nasal lamellae; dorsal surface of adults brownish, covered with diffuse orange and dusky blotches, and indistinct pale spots; melanophores pronounced on dorsal surface, and dorsal fins largely pale anteriorly, darker posteriorly with a blackish blotch above the free rear tip when fresh.
Description. Disc broadly wedge shaped, bluntly angular anteriorly and mildly bottlenose shaped, margin concave near tip then almost straight to its apex; snout angle before eyes 56o (56–60o in 4 paratypes); outer margins broadly rounded, more narrowly rounded distally; females slightly broader than males, length 1.37 in holotype (1.31–1.37 in adult male paratypes, 1.27–1.30 in adult-sized females) times width. Pelvic fins elongate, shortbased, base length 0.84 (0.85–1.06 in all paratypes) of inner margin length; total length 2.12 (1.81–2.29) times their base length, 2.69 (2.15–2.58) times width; anterior margin double concave, strongly concave anteriorly, apex broadly rounded, posterior margin noticeably convex. Tail elongate, slender anteriorly, tapering gradually; in crosssection nearly flat below, rounded slightly above; tail length from anterior cloaca 1.38 (1.28–1.46) times precloacal length, 1.35 (1.21–1.44) times disc length, 6.26 (5.90–6.10, 4.98–6.44) times its width at pelvic-fin insertions; tail width sexually dimorphic anteriorly, 2.09 (2.16–2.20, 2.28–2.51) times depth at pelvic-fin insertions, 2.52 (2.40–2.50, 2.39–2.73) at first dorsal-fin origin, 2.03 (1.90–2.12, 1.93–2.17) at second dorsal-fin origin. Dermal fold lateral on tail, originating forward of free rear tip of pelvic fin, reaching just behind ventral caudal-fin origin; fold moderately well developed, maximum width at about at end of interdorsal space; width about half width of Head elongate, its ventral length 29.2 (27.4–31.3)% TL; snout moderately long and bluntly pointed; preoral length 3.41 (2.92–3.31) times mouth width, 7.43 (7.26–7.79, 7.11–7.52) times internarial distance, 1.45 (1.21–1.46) times dorsal caudal-fin margin, 5.44 (5.45–6.44, 4.60–5.48) times distance from nostril to margin of disc; preorbital snout length (direct) 3.40 (2.95–3.31) times interspiracular length, 4.69 (3.90–4.80) times orbit diameter, 5.22 (3.94–5.01) times interorbital width; interorbital space weakly concave to flat, rather broad; eye dorsolateral, not elevated or protruding, orbit relatively small, diameter 1.58 (1.35–1.68) times spiracle length, 1.11 (0.82–1.21) times interorbital distance. Spiracles narrowly bean-shaped, relatively large; two strongly compressed folds on posterior margin, length of innermost spiracular fold 0.8 (0.7–0.9) of outer fold length; distance between bases of folds 0.7 (0.5–0.8) length of shortest fold. Nostril moderately large, oblique, nasal flaps well developed; anterior aperture suboval, width slightly exceeding length; nostril length 3.22 (2.93–3.49) times anterior aperture width, 1.35 (1.30–1.57) times anterior nasal-flap base 0.94 (1.14–1.18, 0.93–1.05) times distance from nostril to edge of disc, 1.29 (1.30–1.61) times internarial distance. Anterior nasal flap moderate with long, slender process anteriorly; flap base length 1.86 (1.90–2.09, 1.28–1.70) times its width at process, 2.38 (2.03–2.47) times anterior aperture width; inserted by about length of longest spiracular fold into internarial space; distance between insertions of flaps 3.38 (3.27–3.88) in greatest distance across nostrils anteriorly, 1.05 (1.00–1.09) in minimum internarial distance; process of flap about twice as long as wide, bluntly pointed distally, abutting posterolateral nasal flap and determining hind margin of anterior aperture. Posterolateral nasal flap lobe-like, broadest medially, length 4.99 (3.06–6.27) times width; originating just behind lateral extremity of anterior nasal aperture, extending postero-medially as a free fold to about level of insertion of anterior nasal flap and almost to inner edge of posterior nasal flap. Posterior nasal flap strongly lobe-like, base length 2.22 (1.85–2.74) times its width, its innermost edge well short of innermost margin of nostril; width 0.98 (0.80–1.07) times anterior aperture width, 1.65 (1.02–2.19) times posterolateral nasal-flap width.
Mouth width 1.69 (1.50–1.79) times nostril length, 7.06 (6.61–7.26) in precloacal length; positioned over hind margin of orbit. Upper jaw weakly convex, upper lip arched slightly; lower lip pronounced, separated from oral groove by ridges of strongly corrugated skin; deep, short lateral grooves around corners of mouth. Teeth very small, rhomboidal, quincuncial; crowns blunt or with weak posterior cusps; cusps most prominent near jaw angle; ca. 78 (65–92) rows in upper jaw; upper and lower jaw teeth similar in shape and size, similar between sexes, slightly larger toward symphysis. Gill openings s-shaped, fifth less so; length of third gill slit 2.52 (2.51–2.90, 2.00–2.34) in nostril length, 6.15 (5.83–6.41, 5.31–5.76) in distance between fifth gill slits; distance between first gill slits 1.42 (1.41–1.51) times distance between fifth gill slits; distance between fifth gill slits 3.14 (3.17–3.73) times internarial distance, 1.44 (1.42–1.61) times mouth width, 0.29 (0.29–0.34) of ventral head length.
Dorsal fins variable in shape and height, upright, broad to falcate; apices narrowly rounded to almost angular; anterior margins weakly convex, more extremely convex in some individuals; posterior margins weakly to deeply concave; free rear tips almost forming right angle, not produced; first dorsal fin marginally taller than second, length of first 1.05 (0.84–1.02) times its height, base length 1.38 (1.58–1.81) times inner margin length; second dorsal-fin length 1.15 (1.02–1.28, 0.95–1.12) times its height, base length 2.06 (1.96–2.54) times inner margin length. First dorsal fin well behind pelvic-fin rear tip, interspace 0.78 (0.74–0.96) times interdorsal distance; interdorsal space moderate, 2.12 (1.79–1.98, 1.68–1.97) times second dorsal-fin height, 3.19 (2.63–2.91) times base of first dorsal fin, 1.43 (1.33–1.41, 1.11–1.37) times tail width at origin of first dorsal fin, 1.71 (1.64–1.81) times interspace between second dorsal-fin insertion and upper origin of caudal fin. Caudal fin medium-sized, deep; dorsal caudal margin 2.28 (2.05–2.57) times preventral margin length.
Dermal denticles of holotype mostly minute, narrowly arrow-shaped with prominent ridges on an elevated crown, not close-set, covering entire body and fins; most of surface uniformly finely granular, but denticles becoming enlarged along dorsal midline and infraorbit, enlarged slightly (barely evident without magnification) on midline of tail between dorsal fins, and on precaudal midline, snout tip, lateral margin of disc anteriorly, and lateral fold; enlarged denticles often irregular in shape, globular with flattened crowns and/or crenulate anterior margins; a dense covering of small denticles over nasal lamellae. Prebranchial sensory pore patch concealed, extending to just behind level of first gill slit. Postscapular sensory canals embedded, weakly undulated anteriorly, terminating just forward of pectoral-fin insertions; sensory pores minute; sensory canal not forming a shallow groove.
Rostral cartilage in paratype SUML MMLM 0 12 (sex, size) broad, its shaft barely increasing in width in a posterior direction; rostral node very broadly expanded and elongate, rounded apically, not angular, axis at widest part of node 27.1% of length of rostral cartilage from snout tip; precerebral cavity broad and uniformly convex posteriorly, converging to a point anteriorly at rostral node, dorsolateral edges of cartilage surrounding cavity (rostral ridges on surface of snout) slightly separated posteriorly, not constricted medially; rostral cartilage about 65% of length of neurocranium, ventral edges of rostral cartilage united; nasal capsules large, their transverse axes anterolaterally directed; maximum width across capsules 1.25 times nasobasal length of cranium (base of rostrum to occipital condyles); length of nasal capsule about equal to its width; basal plate narrow, its minimum width 4.78 times in nasobasal length; cranial roof with small oval fenestra, located well behind precerebral cavity (separated by 1.4 times its length); anterior cartilage broadly triangular, posterior apex narrowly rounded, without an anterior lobe extending beyond nasal capsules; preorbital processes indistinct; postorbital processes well developed, strongly bifurcate, posterior process most pronounced; greatest width across processes 1.49 times in nasobasal length.
Nasal lamellae 51 (50–53). Pectoral skeleton with 29 (30–32, n = 5) propterygial, 7–8 (6–8) mesopterygial, 1–2 (1–2) neopterygial, 25 (26–29) metapterygial and 63 (66–70) total radials; anterior radials of propterygium (in paratype SUML F1) extending forward of nasal capsules by about 12.7% of rostral length. Total pelvic radials 25 (24–26 in males, n = 3) excluding clasper; 25–26 in females (n = 2). Vertebral column with 192 (185–191, n = 5 paratypes) total segments (synarcual and free), 178 (173–179) post-synarcual centra; 146 (138–147) total precaudal centra (including synarcual); 14 (11–14) synarcual segments; 25 (23–27) monospondylous precaudal centra, all posterior centra of holotype with ribs; 107 (101–107) diplospondylous precaudal centra; 46 (43–48) diplospondylous caudal centra.
Colour. Fresh (based on image of holotype, PNM 15189). Dorsal surface medium greyish brown, covered with a complex (but subtle) mottled pattern of poorly defined white spots and large diffuse dusky and orange blotches; white spots scattered, small, similar in size to spiracular folds, most obvious on central disc and anterior tail; snout apex slightly darker than rest of snout; dusky blotches similar in size to eye diameter, most pronounced near outer part of disc; narrow white margins along pelvic fins and anterior disc; orange blotches most evident on central disc and near margins of tail; orbital membrane dusky. Ventral surface mostly white; pinkish to translucent beside rostral cartilage; broad dusky margins on both posterior disc and pelvic fins. First dorsal fin pale brownish and weakly blotched anteriorly, its posterior half darker, dusky to blackish; second dorsal and caudal fins dark brownish near fin origin, becoming pale yellowish medially, then semi translucent with dusky blotches posteriorly; an obvious subcircular blotch over inner margins of both dorsal fins; margin of ventral lobe of caudal fin white.
In preservative. Dark greyish brown dorsally, orange blotches more obvious (each about eye size or slightly smaller, becoming increasingly more evident as skin dries, see Fig. 5 A); blotches most strongly contrasted with pale area of snout lateral to rostral cartilage; white spots barely detectable in most types; melanophores large, densely packed and prominent over most of surface (see Fig. 8 B–D for paratype CSIRO H 7542–04); dorsal fins pale anteriorly with darker areas posteriorly, large dark spot evident above inner margins of holotype and most paratypes; caudal fin blotched, dusky, darkest near fin apex. Ventral surface creamy white; posterior disc and pelvic fins with white-edged dark margin still evident in holotype, less so in some paratypes.
Size. Available material consists of 12 males and 10 females; adult males ranged from 556–720 mm TL, and the holotype was adolescent at 593 mm TL; adult females probably larger than males, several exceeded 720 mm TL with the largest being 844 mm TL; birth size and reproductive information unknown.
Distribution. Collected from fish markets in the central and southern Philippines at Danao and Cebu Cities (Cebu), Baliangao and Dipolog City (Mindanao), and Bacolod, Cadiz and Dumaguete Cities (Negros). Probably more widely distributed in seas of the Philippine Archipelago but exact information available from fishermen.
Etymology. Epithet in recognition of the considerable efforts of colleague Dr William White who has contributed so much to the taxonomic and biological knowledge of sharks and rays of the Western Central Pacific over the past decade. The vernacular name, Philippine guitarfish, follows Compagno et al. (2005) with reference to its known distribution in the Philippines, and where it was first collected as part of a WWF–funded project to investigate the biodiversity of chondrichthyans of the region.
Molecular analysis. The analysis of the NADH2 data suggests that Rhinobatos whitei represents a monophyletic lineage that is distinct from, but closely related to, R. jimbarensis and that these two species, in turn, are sister to a clade containing R. punctifer from the Arabian Sea and R. penggali from Indonesia. We caution however that this inference is based on a single mitochondrial marker. Inclusion of multiple nuclear markers could affect the presented inference. A closely related form from nearby Borneo differs slightly from R. whitei and may be another undescribed species.
Comparisons. Several guitarfishes in the Western Central Pacific have been confused with Rhinobatos schlegelii Müller & Henle. Herre (1953) did not report a ray referable to R. whitei in his checklist of Philippine fishes. The Philippine species, subsequently referred to by Compagno et al. (2005) as Rhinobatos cf. schlegelii, is distinct from R. schlegelii (occurring off Japan and Taiwan) in morphology (i.e. body form, squamation, and colour pattern) and its NADH2 gene sequence. The types of R. schlegelii were examined recently by Bernard Seret and the first author as part of a broader investigation of Rhinobatos of the western North Pacific. Rhinobatos schlegelii differs from R. whitei in some meristic and morphological details. Rhinobatos whitei has a much lower free precaudal centra count (126–133 vs. 142–148 centra in R. schlegelii) but typically more caudal centra (43–48 vs. 31–43 centra), fewer pelvic rays (24–26 vs. 27–30 elements in males, excluding the clasper), a broader pectoral disc (width 30.9–34.6% vs. 27.9–30.8% TL) and mouth (width 5.7–6.5% vs. 5.5–5.6% TL), and larger spiracles (width 2.4–2.8% vs. 1.9–2.2% TL). Rhinobatos schlegelii has a more bottlenose shaped snout with a black teardrop marking on its ventral surface (most obvious in young and absent in R. whitei).
Rhinobatos whitei belongs to a group of plain or weakly patterned (rather than distinctly white spotted) guitarfishes of the genus that includes two other valid nominal species in the Western Central Pacific, R. jimbaranensis and R. sainsburyi. Another nominal species considered valid by several authors (see Fricke & Eschmeyer, 2014), R. formosensis, is thought to be a synonym of R. schlegelii (Seret et al., in prep).
Rhinobatos whitei differs from R. jimbaranensis from nearby Indonesia in its NADH2 sequence (see Fig. XX). Both species are covered with rusty brown blotches but unlike R. jimbaranensis, R. whitei is also covered with faint white spots and has bicoloured dorsal fins. Rhinobatos whitei has fewer pelvic radials (females 25–26 vs. 27–29 in R. jimbaranensis), slightly fewer monospondylous precaudal centra (23–27 vs. 26–29, although the total counts of centra were similar), and the pelvic-fin inner margin is longer than (rather than shorter than or equal to) its base in males, and the anterior cartilage is broadly triangular (rather than sickle-shaped). There are also differences in other morphometric rations: snout length 3.0–3.4 (vs. 3.4–3.6 in R. jimbaranensis) times interspiracular distance; preoral length 6.8–7.8 (vs. 7.7–8.1) times internarial distance, 2.0–3.4 (vs. about 3.7 in 5 types) times mouth width and 1.2–1.5 (1.5–1.7) times dorsal caudal-fin margin; nostril length 0.9–1.2 (vs. 0.8–0.9) times distance from nostril to edge of disc; distance between insertions of anterior nasal flaps 3.3–3.9 (vs. 3.0–3.3) in greatest distance across nostrils anteriorly, 1.00–1.09 (vs. 0.89–0.97) in minimum internarial distance; and mouth width 6.6–7.3 (7.8–8.0) times in precloacal length.
Rhinobatos sainsburyi from Australian seas is quite different in body shape. It has a very short snout compared to R. whitei (preorbital length 2.5–2.6 vs. 3.0–3.4 times interspiracular distance), a larger eye (orbit diameter 1.6–1.9 vs. 1.4–1.7 times spiracle length), its ventral head is 2.5–2.9 vs. 2.9–3.4 times distance been the 5th gill slits, and has fewer post-synarcual centra (162–171 vs.173–179). R. sainsburyi is variable in coloration, being either plain yellowish brown or with dark blotches but always lacking white spots.
Of the other species of Rhinobatos in the Western Central Pacific, it differs from R. hynnicephalus (Taiwan and Japan) in lacking dark spots and ring-like markings in adults, more pectoral radials (66–70 vs. 60–64), typically higher vertebral count (total free centra 173–179 vs. 165–175), and several morphometric differences. Another Indonesian species, Rhinobatos pengalli clusters away from the other Western Pacific Rhinobatos together with R. punctifer from the western Indian Ocean. Both of these species have prominent white spots over a very broad disc (width of pectoral disc in R. pengalli 36–37% vs. 31–35% TL in R. whitei). It also has fewer post-synarcual centra (166–170 vs. 173–179) than R. whitei.
NJ tree
R. whitei Sulu Sea Philippines GN2253 R. whitei Sulu Sea Philippines GN2254 R. whitei South China Sea Philippines GN4326 R. whitei Sulu Sea Philippines GN2244 R. whitei South China Sea Philippines GN4388 R. sp. 1 Sabah South China Sea GN3605 R. sp. 1 Sarawak South China Sea GN2906 R. jimbaranensis Indonesia GN 11251
R. jimbaranensis Indonesia GN 11253
R. jimbaranensis Indonesia GN 11254
R. jimbaranensis Indonesia GN 11255
R. punctifer Oman GN 9643
R. punctifer Oman GN 9504
R. punctifer Oman GN 9644
R. punctifer Oman GN 7654
R. punctifer Oman GN 7653
R. punctifer Oman GN 7655
R. punctifer Oman GN 9646
R. punctifer Oman GN 7650
R. penggali Indonesia GN 11258
R. penggali Indonesia GN 11259
R. penggali Indonesia GN 11256
R. hynnicephalus Tashi Taiwan GN 10259 R. hynnicephalus Wuchi Taiwan GN 10245 R. hynnicephalus Wuchi Taiwan GN 10244 R. hynnicephalus Tashi Taiwan GN 10258 R. hynnicephalus Tashi Taiwan GN 10260 R. hynnicephalus Ariake Bay Japan GN 12938 R. hynnicephalus Wuchi Taiwan GN 10247 R. hynnicephalus Wuchi Taiwan GN 10243 R. hynnicephalus Wuchi Taiwan GN 10246 R. hynnicephalus Wuchi Taiwan GN 10242 R. hynnicephalus Wuchi Taiwan GN 10241 R. hynnicephalus Ariake Bay Japan GN 12936 R. hynnicephalus Ariake Bay Japan GN 12937 R. schlegeli Ariake Bay Japan GN 12935
R. schlegelii Tashi Taiwan GN 10256
R. schlegelii Tashi Taiwan GN 10257
R. schlegelii Yilan Taiwan GN 13862
R. schlegelii Tashi Taiwan GN 10038
R. schlegelii Taiwan Strait Taiwan GN6187
R. schlegelii Tashi Taiwan GN 10039
R. schlegelii Tashi Taiwan GN 10252
R. schlegelii Tashi Taiwan GN 10253
0.005 substitutions/site
Holotype Adult males Large females Immature males MIN MAX MIN MAX MIN MAX ......continued on the next page Holotype Adult males Large females Immature males MIN MAX MIN MAX MIN MAX Remarks. Our material displays a high level of intraspecific variability in some anatomical features. For example, the dorsal fins of the adolescent male holotype (PNM 15189, 597 mm TL) and paratype female (SUML F1, ca 686 mm TL) differ in shape from paratypes (SUML JPAG 300, 301, 306, 308 and 310, 471– 641 mm TL) to an extent that they might be considered different species (broad fins with rounded apices compared to narrow and strongly falcate). These differences do not appear to be related to growth or sexual dimorphism, as morphometrics and NADH2 analysis support only a single taxon.
Coloration in this species is varies intraspecifically, but also in a major way before and after preservation. Aspects of pattern, such a feeble white spotting and indistinct darker blotches on the dorsal surface, if detectable, are barely evident after preservation.
description: Published as part of Last, Peter R., Corrigan, Shannon & Naylor, Gavin, 2014, Rhinobatos whitei, a new shovelnose ray (Batoidea: Rhinobatidae) from the Philippine Archipelago, pp. 31-47 in Zootaxa 3872 (1) on pages 33-45, DOI: 10.11646/zootaxa.3872.1.3, http://zenodo.org/record/287210