Carcharhinus coatesi ( Whitley, 1939 )

White, William T., 2012, A redescription of Carcharhinus dussumieri and C. sealei, with resurrection of C. coatesi and C. tjutjot as valid species (Chondrichthyes: Carcharhinidae), Zootaxa 3241, pp. 1-34 : 3-10

Carcharhinus coatesi ( Whitley, 1939)

Figs 1 –3; Table 1

Platypodon coatesi Whitley, 1939: 234 , fig. 7 (Type locality: Hinchinbrook Passage, Queensland, Australia). Carcharhinus sealei ( Pietschmann, 1913) — Garrick (1982): 41.

Carcharhinus dussumieri ( Müller & Henle, 1839) — Stevens & McLoughlin (1991): 170.

Holotype. QM I 6226, adult male 790 mm TL, Hinchinbrook Passage, Queensland, Australia, ~ 18°20’ S, 146°08’ E, April 1938, collected by G. Coates.

Other material. 19 specimens: CSIRO CA 707, adult male 703 mm TL, Bickerton Island, Northern Territory, Australia, 13°42’ S, 136°15’ E, 22th March 1979, collected by J. Waddy; CSIRO CA 1655, juvenile male 389 mm TL, northwest of York Sound, Western Australia, 14°03’ S, 124°31’ E, 27th March 1981, 86– 91 m depth; CSIRO CA 3375, subadult male 657 mm TL, North West Shelf, Western Australia, 13th November 1982; CSIRO H 3363– 0 4, female 403 mm TL, west of Cape York Peninsula, Gulf of Carpentaria, Queensland, Australia, 11°16’ S, 140°00’ E, 5th February 1993, 59 m depth, collected by G. Yearsley; CSIRO H 4009–01, adult male 813 mm TL, west of Monte Bello Islands, Western Australia, 20°16’ S, 115°00’ E, 22nd August 1985, 113– 123 m depth, collected by A. Graham and G. Yearsley; CSIRO H 5608–01, female 731 mm TL, south of Tasman Point, Groote Eylandt, Gulf of Carpentaria, Queensland, Australia, 14°29’ S, 136°22’ E, 8th October 1998, 27 m depth, collected by J. Salini; CSIRO H 6582–05, female 728 mm TL, CSIRO H 6582–06, female 791 mm TL, CSIRO H 6582–07, female 709 mm TL, CSIRO H 6582–08, female 732 mm TL, CSIRO H 6582–09, female 708.5 mm TL, northwest of Cape Leveque, Western Australia, 15°04’ S, 121°48’ E, 28th June 2007, 90– 96 m depth, collected by A. Graham and J. Pogonoski; CSIRO H 7169–02, female 733 mm TL, Deception Bay, Western Australia, 15°37’ S, 124°25’ E, 11th August 2005, collected by R. Pillans; CSIRO H 7294–01, female 760 mm TL, west of Deception Bay, Western Australia, 15°40’ S, 124°23’ E, 16th August 2005, collected by R. Pillans & R. McAuley; QM I 17862, female 534 mm TL, off Darwin, Northern Territory, 12°25’ S, 130°48’ E, 15th July 2008, collected by T. White; QM I 27890, female 783 mm TL, Gulf of Carpentaria, Queensland, 11°00’ S, 140°41’ E, 4th December 1990, 47m depth, collected by J. Johnson; QM I 28815, juvenile male 417 mm TL, Gulf of Carpentaria, Queensland, 13°59’ S, 138°42’ E, 10th December 1990, 55 m depth, collected by J. Johnson & S. Cook; QM I 28833, juvenile male 371 mm TL, QM I 28834, female 408 mm TL, Gulf of Carpentaria, Northern Territory, 10°00’ S, 137°41’ E, 13th December 1990, 41 m depth, collected by J. Johnson & S. Cook; QM I 34826, juvenile male 351 mm TL, QM I 34827, juvenile male 357 mm TL, QM I 34828, juvenile male 339 mm TL, Gulf of Carpentaria, Northern Territory, 10°07’ S, 137°42’ E, 10th December 1990, 46 m depth, collected by J. Johnson.

Diagnosis. A small species of Carcharhinus with: a moderately long and narrowly rounded snout; upper anterior teeth oblique and blade-like, coarsely serrated, lateral margin deeply notched and with several large and smooth basal cusplets; lower anterior teeth narrower, slightly oblique, lateral margins notched and usually several smooth basal cusplets; total tooth row counts 24–26/23–25, or 47–51; interdorsal space with ridge on midline, 18.0–23.1% TL; first dorsal fin moderately tall and slightly falcate, origin just anterior to pectoral-fin free rear tip, length 14.8–17.3% TL, 1.5–1.9 times height, inner margin 2.0– 2.8 in base; second dorsal fin much smaller than first, broadly triangular, height 28–37% of first dorsal-fin height, origin about opposite to anal-fin origin; anal fin falcate, height 0.9–1.4 times second dorsal height, base 0.9–1.2 times second dorsal-fin base; colour pale brownish to grey dorsally, whitish ventrally; second dorsal fin with a black blotch on upper one to two thirds of fin, not extending onto upper surface of body and well defined from ground colour; other fins plain or with pale outer margins; total vertebral counts 134–147; monospondylous precaudal counts 42–50; diplospondylous precaudal counts 22–33; diplospondylous caudal counts 64–73; precaudal counts 67–76.

Description. Body slender, trunk oval-shaped to almost pear-shaped in section at first dorsal-fin base, length of trunk from fifth gill slits to vent 1.09 (1.01–1.41) times head length; no predorsal or postdorsal ridges; a moderate to strong interdorsal ridge present; lateral ridges absent. Caudal peduncle moderately stout, roughly hexagonal in section at second dorsal-fin insertion, postdorsal and postventral spaces flattened and usually with a very shallow median groove, lateral surfaces somewhat rounded to angular; no lateral ridges or keels; height of caudal peduncle at 2nd dorsal-fin insertion 1.03 (1.00–1.39) times its width, 2.40 (1.84–2.26) times in dorsal–caudal space. Precaudal pits prominent; upper pit a pronounced, deep, arcuate and crescentic; lower pit smaller but as pronounced.

Head length to 5th gill opening 0.87 (0.80–1.21) times in pectoral–pelvic space; moderately stout, not flattened, ellipsoidal in shape in cross-section at eyes. Outline of head in lateral view slightly undulated dorsally, medially slightly concave on snout, nearly straight above eye, concave at nape and nearly straight and progressively elevated above gills to first dorsal fin; slightly convex to nearly straight ventrally along lower jaws and beneath gills. In dorsoventral view, head anteriorly rounded to parabolic. Snout moderately long, preoral snout length 0.79 (0.83– 1.14) times mouth width; tip narrowly rounded in dorsoventral view and sometimes weakly indented anterior to nostrils; snout acutely rounded in lateral view, slightly convex above and below.

External eye opening of fleshy orbit without anterior or posterior notches. Eyes moderately large, circular in shape (sometimes slightly oval), height 1.16 (1.08–1.41) in length, length 9.52 (7.71–12.11) times in head length; situated very slightly dorsolateral on head, with lower edges almost crossing horizontal head rim in dorsal view; subocular ridges absent. Nictitating lower eyelids internal, with deep subocular pouches and secondary lower eyelids fused to upper eyelids.

Spiracles absent. Gill slits large, first four gill slits subequal in height, third and fourth gill openings subequal and largest, fifth smallest; fifth slit about 0.78 (0.61–0.91) of height of third; height of third 7.81 (6.81–10.29) in head length, 1.22 (0.86–1.61) times eye length; margins of first four gill slits nearly straight to weakly concave, fifth weakly concave; upper edges of gill slits 2 and 3 most elevated, upper ends about level with upper three quarters of eye. Gill filaments not visible from outside in lateral view. Gill-raker papillae absent from gill arches.

Nostrils with moderately large, subcircular incurrent apertures; relatively long, triangular anterior nasal flaps with narrowly pointed tips, posterior nasal flap vestigial, small circular excurrent apertures; well in front of mouth; width 2.93 (2.24–3.07) in internarial width, 1.51 (1.09–1.65) in eye length, 1.78 (1.23–2.08) in longest gill-opening.

FIGURE 3. Dentition of Carcharhinus coatesi ( CSIRO H 7294–01, female 760 mm TL): A. 4th upper anterolateral tooth on left side (image reversed); B. 3rd lower anterolateral tooth on right side.

Mouth moderately large, narrowly arched to somewhat angular; width 2.83 (2.88–3.59) in head length; mouth length 1.57 (1.36–1.67) in mouth width. Lips concealing teeth when mouth is closed. Tongue large, flat and broadly rounded, filling floor of mouth. Maxillary valve narrow, width less than half of eye length, not strongly papillose. No large buccal papillae on floor or roof of mouth behind maxillary valve. Palate, floor of mouth and gill arches covered with buccopharyngeal denticles for most of its length. Labial furrows inconspicuous, restricted to mouth corners and barely visible in ventral view. Labial cartilages appear to be absent.

Teeth relatively few, in 24–26/23–25, or 47–51 total rows (both jaws, n=6). Teeth not arranged in diagonal files, no toothless spaces at symphysis. Teeth highly differentiated in upper and lower jaws and along jaws. Tooth formula (n=6): upper jaw 11–12 + 1–2 + 11–12, lower jaw 11–12 + 1 + 11–12. Upper anterolateral teeth with moderately broad, oblique, blade-like cusps; lateral margins deeply notched; medial margins convex basally, nearly straight distally; several large cusplets basally on lateral margin; medial margin with coarse serrations, lateral margin usually with some coarse to fine serrae; basal cusplets smooth, without serrations (Fig. 3a). Lower anterolateral teeth with narrower, slightly oblique cusps; lateral margins notched, with several small to large, smooth basal serrae; medial margins concave; both margins smooth distally, often with some fine serrations basally (Fig. 3b).

Lateral trunk denticles with flat, rhomboidal crowns wider than long, closely imbricate; crowns with 5 prominent longitudinal ridges that extend its entire length onto the cusps; medial cusp very short but strong, with two pairs of lateral cusps. Denticles absent from insertion of the fins and from dorsal surface and inner sides of claspers in males.

Pectoral fins moderately large, relatively narrow, weakly falcate; anterior margin moderately convex, apices narrowly rounded to pointed; posterior margin moderately concave; free rear tip moderately rounded, inner margin convex; base broad about 54 (46–56)% of fin length; length from origin to rear tip 0.98 (0.90–1.03) times anterior margin length; slightly larger in area to first dorsal fin; origin under fourth gill slit; fin apex just anterior to level of first dorsal-fin insertion when fin is elevated and adpressed to body.

Pelvic fins triangular and not falcate; length of anterior margins 0.43 (0.36–0.47) of pectoral–fin anterior margins; area larger than that of anal fin; anterior margin nearly straight; apices angular; posterior margin nearly straight; free rear tip bluntly rounded to angular, inner margin nearly straight. Claspers of adult males moderately long, outer length 9.0 (7.9–8.6)% of TL, base 18.7 (15.8–20.7) in outer length.

First dorsal fin moderately tall, slightly falcate; anterior margin nearly straight and slightly convex near apex, shallowly concave basally; posterior margin slightly concave to nearly straight (excluding free rear tip), almost perpendicular to horizontal axis to angling slightly anteroventrally from apex; free rear tip acutely pointed, inner margin shallowly concave; origin over or just anterior to pectoral-fin free rear tip; midpoint of base 1.31 (1.02– 1.56) times closer to pelvic origins than pectoral insertions; free rear tip just anterior to pelvic-fin origins by about an eye length. First dorsal-fin base 1.78 (1.53–2.11) in interdorsal space, 2.19 (2.00–2.76) in dorsal caudal margin; height 1.16 (1.00–1.38) in base; inner margin 2.19 (1.70–2.33) in height, 2.55 (2.03–2.83) in base.

Second dorsal fin small, broadly triangular, very weakly falcate; height 0.34 (0.28–0.37) second dorsal-fin height; base 0.59 (0.50–0.70) times first dorsal-fin base; anterior margin concave basally, becoming weakly convex distally; apex moderately rounded; posterior margin slightly concave; free rear tip acutely pointed, inner margin nearly straight; origin well behind pelvic-fin free rear tips and about opposite to slightly posterior to anal-fin origin; rear tip slightly posterior to anal-fin free rear tip, in front of upper caudal-fin origin by 1.28 (0.77–1.23) times its inner margin length; posterior margin curving posteroventrally from apex; insertion slightly posterior to fin apex. Second dorsal-fin base 1.22 (0.99–1.35) in dorsal–caudal space; height 2.02 (1.83–2.44) in base; inner margin 1.08 (1.13–1.47) in height, 1.87 (1.43–1.98) in base.

Anal fin falcate and apically narrow; height 1.14 (0.95–1.37) times second dorsal-fin height, base length 0.95 (0.90–1.18) times second dorsal-fin base; anterior margin moderately convex; apex bluntly angular; posterior margin deeply concave; free rear tip acutely pointed, inner margin nearly straight; origin slightly anterior to second dorsal-fin origin; insertion opposite or slightly anterior to second dorsal-fin insertion, about level with fin apex; free rear tip in front of lower caudal-fin origin by about or slightly more than its inner margin length; posterior margin almost vertical and then abruptly posterodorsally from apex. No preanal ridges obvious. Anal-fin base 1.23 (1.02–1.38) in anal–caudal space; height 1.68 (1.65–2.19) in base; inner margin 0.88 (0.98–1.32) in height, 1.91 (1.50–2.08) in base.

Caudal fin very narrow-lobed and asymmetrical, with short terminal lobe and prominent, long, narrow, nonfalcate ventral lobe; dorsal caudal margin proximally and distally convex, and slightly concave just anterior to subterminal notch, with prominent lateral undulations; preventral margin convex, tip of ventral caudal-fin lobe angular; lower postventral margin almost straight; upper postventral margin nearly straight except for convex section at subterminal notch; subterminal margin nearly straight; terminal margin slightly to moderately concave, lobe formed by these margins angular, tip of tail angular to narrowly rounded. Length of dorsal caudal margin 2.87 (2.44–3.18) in precaudal length, preventral caudal margin 2.33 (2.14–2.53) in dorsal caudal margin, terminal lobe from caudal tip to subterminal notch about 3.37 (3.01–3.44) in dorsal caudal margin, subterminal margin length 2.29 (2.01–2.63) in terminal margin.

Counts of total vertebral centra (TC) 147 (134–145), precaudal centra (PC) 76 (67–75), monospondylous precaudal (MP) centra 47 (42–50), diplospondylous precaudal (DP) centra 29 (22–33), diplospondylous caudal (DC) centra 71 (64–73); MP centra 32.0 (29.0–35.5)%, DP centra 19.7 (15.5–22.8)%, and DC centra 48.3 (46.8– 51.4)% of TC centra. Ratios of DP/MP centra 0.62 (0.47–0.79), DC/MP centra 1.51 (1.32–1.67). Transition between MP and DP centra usually posterior to pelvic girdle. MP-DP transition usually very difficult to locate, forming a`stutter zone' of alternating long and short centra posterior to largest centra.

Colour. Dorsal surfaces greyish to brownish (bronze hue when fresh), whitish ventrally and on lower sides. Demarcation between darker dorsal and paler ventral colours (waterline) extending from snout to lower margin of eye, then from middle of posterior eye through middle of gill slits to pectoral-fin base; from pectoral-fin insertion extending up to about third height of body then level until below posterior 1st dorsal-fin base before extending up to about midlevel of sides; extending along posterior body to caudal peduncle at or just above mid-lateral sides; edge of waterline mostly diffuse, sharpest on head and caudal peduncle. First dorsal fin without markings; second dorsal fin with a distinct black apical blotch on upper one to two thirds of fin, usually whitish below black blotch on free rear tip, not extending onto upper sides of body below second dorsal-fin base; pectoral, pelvic and anal fins sometimes with a paler posterior margin; caudal fin often with whitish apices.

Size. Specimens examined in this study ranged from 389–813 mm TL. Stevens & McLoughlin (1991) reported maximum sizes for males and females of 870 and 880 mm TL; maturity in both sexes is attained at about 700 mm TL; size at birth of 380–400 mm TL; reproduction apparently not seasonal; litter size of 1–3 (mean 2).

Distribution. Occurs off northern Australia (from Shark Bay in Western Australia to Fraser Island in Queensland) and possibly also off New Guinea ( Last & Stevens, 2009); close inshore to at least 123 m depth. Capture locations of examined specimens shown in Figure 4 .

Etymology. Whitley described this species in 1939 and named it after George Coates who collected many elasmobranchs and fishes in North Queensland.

continued next page Carcharhinus coatesi Carcharhinus sealei

Other material (n = 19) Other material (n = 11)

Holotype Min. Max. Mean Neotype Min. Max. Mean continued next page

Figures

FIGURE 1. Lateral view of Carcharhinus coatesi: A. line drawing of holotype from Whitley (1939); B. holotype QM I 6226 (adult male 790 mm TL), preserved; C. CSIRO H 6582 – 05 (female 728 mm TL), fresh.

FIGURE 4. Locality records for the type and other examined specimens, including other verified records, for the four species in the sealei-dussumieri complex: C. coatesi holotype (hollow circle) and other specimens (solid circles); C. dussumieri lecto- and paralectotypes (hollow stars) and other specimens (solid stars); C. sealei neotype (hollow square) and other specimens (solid square); C. tjutjot lecto- and paralectotype (hollow triangle) and other specimens (solid triangles); C. sp. (cross).

Tables

TABLE 1. Proportional dimensions as percentages of total length for the holotype (QM I 6226) of Carcharhinus coatesi and neotype (CSIRO H 4919 – 04) of Carcharhinus sealei, and ranges and means for the other specimens measured of both species.

TOT (mm) PRC PD2	Holotype 790 73.7 58.7	Carcharhinus coatesi Other material (n = 19) Min. Max. Mean 339 813 575 71.1 75.6 73.3 56.6 62.5 59.1	Neotype 373 71.6 57.4	Carcharhinus sealei Other material (n = 11) Min. Max. Mean 343 653 523 71.6 74.2 72.9 56.8 59.6 58.4
PD1 PD1 (horiz.) HDL HDL (horiz.) PG1 PG1 (horiz.)	27.2 26.2 22.3 21.1 17.7 17.0	27.0 31.1 28.4 25.8 30.0 27.6 20.2 23.1 21.9 19.1 22.7 21.1 16.4 19.3 17.8 15.1 18.7 17.0	27.1 26.3 20.9 20.4 17.2 16.2	26.7 29.0 27.7 26.4 27.6 27.0 19.6 21.7 20.6 18.8 21.6 20.0 15.6 17.9 16.4 14.4 17.4 15.7
POB POB (horiz.) POR PRN PRN (horiz.) PP1	7.9 6.8 6.2 4.4 3.9 21.3	7.3 9.3 8.2 5.8 7.9 6.9 5.7 7.7 6.5 4.1 5.7 4.8 3.3 4.8 4.1 19.7 22.7 21.0	7.9 7.0 6.5 4.6 3.9 20.2	7.1 8.3 7.7 5.6 7.0 6.3 5.7 6.4 6.1 3.9 4.7 4.3 3.4 4.2 3.7 18.4 20.8 19.6
PP2 SVL PAL	44.6 46.7 58.2	43.2 47.3 44.9 45.9 50.4 47.3 54.7 61.2 57.6	42.9 44.8 55.8	43.2 45.6 44.2 45.6 47.4 46.2 55.8 58.6 57.2
IDS	20.9	18.0 23.1 20.4	20.4	19.0 22.4 21.1
DCS PPS	8.4 19.5	7.4 8.6 7.9 18.5 24.5 20.8	7.6 19.8	7.2 8.8 8.2 19.0 22.5 20.9
PAS ACS	8.4 8.1	6.2 8.9 7.2 7.4 8.7 7.9	8.0 7.5	6.7 9.2 7.8 7.1 8.5 7.8
EYL EYH INO NOW	2.3 2.0 9.2 1.6	1.8 3.0 2.4 1.7 2.5 1.9 8.5 10.4 9.3 1.5 2.0 1.7	2.8 2.2 8.8 1.7	2.1 3.1 2.4 1.6 2.3 1.9 7.6 9.1 8.3 1.6 1.7 1.7
INW ANF MOL MOW	4.5 0.7 5.0 7.9	4.1 5.1 4.6 0.5 0.9 0.7 4.4 5.3 4.8 6.4 8.0 6.9	4.4 0.6 4.3 6.9	3.7 4.3 4.0 0.4 0.6 0.5 3.8 4.7 4.3 6.0 7.0 6.6
ULA	0.3	0.1 0.3 0.2	0.2	0.2 0.4 0.3
LLA	0.0	0.0 0.0 0.0	0.0	0.3 0.3 0.3
GS1 GS2	2.6 2.8	2.1 3.3 2.6 2.3 3.3 2.8	2.5 2.4	2.2 2.7 2.4 2.3 3.0 2.6
GS3	2.9	2.2 3.4 2.9	2.8	2.4 3.1 2.9
GS4	2.8	2.1 3.2 2.7	2.8	2.3 3.4 2.9
GS5 ING	2.2 4.8	1.7 2.7 2.1 3.9 5.2 4.5	1.9 4.3	1.9 2.7 2.3 4.1 5.8 4.7