Carcharhinus dussumieri ( Müller & Henle, 1839 ), Muller & Henle, 1839

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 : 11-17

Carcharhinus dussumieri ( Müller & Henle, 1839)

Figs 5 –7; Table 2

Carcharias (Prionodon) dussumieri Müller & Henle, 1839: 47 , pl. 19—teeth (Type locality: Pondicherry, India). Carcharhias malabaricus Day, 1873: 529 (Type locality: India).

Carcharhinus menisorrah ( Müller & Henle, 1839) — Day (1878): pl. 184 (fig. 1); misidentification. Carcharias menisorrah ( Müller & Henle, 1839) — Blegvad (1944); misidentification.

Charcharhinus menisorrah ( Müller & Henle, 1839) — Reylea (1981); misidentification.

Lectotype. MNHN 1135, juvenile male 373 mm TL, Pondicherry (= Puducherry), India, collected by Bélenger.

Paralectotype. MNHN 1136, juvenile male 441 mm TL, Bombay (= Mumbai), India, collected by Dussumier.

Other material. 6 specimens: CSIRO H 6954–01 (jaws and several vertebrae only), male 730 mm TL, Corniche fish market, Qatar, 16 April 2009, collected by A. Moore; CSIRO H 6955–01 (jaws, dried first dorsal fin, and several vertebrae only), adult male 844 mm TL, Corniche fish market, Qatar, 21 April 2009, collected by A. Moore; CSIRO H 6957–01, juvenile male 478 mm TL, Al Khor fish market, Qatar, 25°41’ N, 51°31’ E, 22 April 2009, collected by A. Moore; CSIRO H 7255–01, adult male 736 mm TL, Sharq fish market, Kuwait City, 29°23’ N, 47°58’ E, 0 6 April 2011, collected by A. Moore; CSIRO H 7256–01, male late-term embryo 372 mm TL (from CSIRO H 7256–02), CSIRO H 7256–02 (jaws only), female 1007 mm TL, Sharq fish market, Kuwait City, 29°23’ N, 47°58’ E, 11 April 2011, collected by A. Moore.

Diagnosis. A small species of Carcharhinus with: a relatively long and narrowly rounded to almost pointed snout; upper anterior teeth oblique and blade-like, coarsely serrated, lateral margin deeply notched and with several large and serrated basal cusplets; lower anterior teeth narrower, slightly oblique, lateral margins notched and usually without large basal serrae, finely serrated; total tooth row counts 27–29/24–30, or 52–59; interdorsal space usually without a ridge, 17.9–20.8% TL; first dorsal fin relatively low and not falcate, origin over middle of pectoral-fin inner margin, length 14.3–16.2% TL, 1.4–1.6 times height, inner margin 2.2–2.5 in base; second dorsal fin much smaller than first, broadly triangular, height 32–37% of first dorsal-fin height, origin about opposite analfin origin; anal fin slightly falcate, height 1.0–1.2 times second dorsal-fin height, base 0.9–1.1 times second dorsalfin base; colour pale brownish dorsally, whitish ventrally; second dorsal fin with a black blotch on upper third of fin, not extending onto upper surface of body and very well defined from ground colour; other fins mostly plain; total vertebral counts 123–138; monospondylous precaudal counts 42–48; diplospondylous precaudal counts 20; diplospondylous caudal counts 59–70; precaudal counts 62–68.

FIGURE 7. Dentition of Carcharhinus dussumieri ( CSIRO H 7256–02, female 1007 mm TL): A. 5th upper anterolateral tooth on right side; B. 5th lower anterolateral tooth on right side.

Description. Body relatively slender, trunk somewhat pear-shaped in section at first dorsal-fin base, length of trunk from fifth gill slits to vent 1.05 (0.96–1.10) times head length; no predorsal or postdorsal ridges; interdorsal ridge absent or very weak; lateral ridges absent. Caudal peduncle moderately stout, roughly square-shaped in section at second dorsal-fin insertion, postdorsal and postventral spaces flattened and with a shallow median groove, lateral surfaces somewhat rounded, no lateral ridges; height of caudal peduncle at 2nd dorsal-fin insertion 1.45 (1.08–1.16) times its width, 2.15 (1.90–2.36) times in dorsal–caudal space. Precaudal pits prominent; upper pit a pronounced, deep, arcuate and crescentic; lower pit smaller and shallower.

Head length to 5th gill opening 0.87 (0.78–0.90) times in pectoral–pelvic space; relatively stout, slightly flattened anteriorly, 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 convex to nearly straight and progressively elevated above gills to first dorsal fin; nearly straight ventrally along lower jaws and beneath gills. In dorsoventral view, head narrowly parabolic anteriorly. Snout relatively long, preoral snout length 0.83 (0.88–1.03) times mouth width; tip narrowly rounded to almost pointed in dorsoventral view and sometimes weakly indented anterior to nostrils; snout somewhat pointed in lateral view, slightly convex above and below.

External eye opening of fleshy orbit without anterior or posterior notches. Eyes moderately large, subcircular, height (1.15–1.27) in length, length 8.87 (9.16–11.88) times in head length; situated laterally on head; subocular ridges absent. Nictitating lower eyelids internal, with deep subocular pouches and secondary lower eyelids fused to upper eyelids.

Spiracles absent. Gill slits large, subequal in height, third and fourth gill openings subequal and largest, first and fifth smallest; fifth slit about 0.74 (0.77–0.92) of height of third; height of third 6.52 (6.75–7.37) in head length, 1.36 (1.32–1.76) times eye length; margins of gill slits usually slightly concave (sometimes nearly straight); 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; moderately long, triangular anterior nasal flaps with pointed tips, posterior nasal flap vestigial, small circular excurrent apertures; well in front of mouth; width 2.92 (2.64–3.02) in internarial width, 1.72 (1.16–1.48) in eye length, 2.11 (1.84–2.21) in longest gill-opening.

Mouth large and moderately rounded; width 2.86 (2.90–3.14) in head length; mouth length 1.71 (1.48–1.65) in mouth width. Lips concealing teeth when mouth is closed. Tongue large, flat and broadly rounded, filling floor of mouth. Maxillary valve narrow, width much 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 to at least first gill arch. Lower labial furrows small and inconspicuous in ventral view; upper labial furrows short but conspicuous in ventral view. Labial cartilages appear to be absent.

Teeth relatively few, in 27–29/24–30 rows or 52–59 total rows (both jaws, n=4). 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=4): upper jaw 13–14 + 1 + 13–14, lower jaw 11–15 + 0–2 + 11–15. Upper anterolateral teeth with moderately broad, oblique, blade-like cusps; lateral margins deeply notched; medial margins slightly convex basally, nearly straight distally; several large cusplets basally on lateral margin; medial and lateral margins of cusp and the lateral basal cusplets with regular coarse serrations; cusps of adult males usually narrower than females and with finer serrations (Fig. 7a). Lower anterolateral teeth with narrower, only slightly oblique cusps; lateral margins notched; medial margins concave; both margins finely serrated; cusps of adult males often more oblique and with less to no serrations (Fig. 7b).

Lateral trunk denticles with flat, rhomboidal crowns wider than long, closely imbricate; crowns with 3 or 5 prominent longitudinal ridges that extend its entire length onto the cusps; medial cusp short but strong, with one or two pairs of lateral cusps. Denticles absent from insertion of the fins and from dorsal surface of claspers in males.

Pectoral fins moderately large, relatively broad, not to weakly falcate; anterior margin moderately convex, apices moderately rounded; posterior margin very slightly to moderately concave; free rear tip moderately rounded, inner margin slightly convex; base broad about 45 (50–54)% of fin length; length from origin to rear tip 0.98 (0.98– 1.10) times anterior margin length; slightly larger in area to first dorsal fin; origin under fourth gill slit; fin apex level with mid-base of first dorsal fin when fin is elevated and adpressed to body.

Pelvic fins triangular, not falcate; length of anterior margins 0.41 (0.43–0.48) of pectoral–fin anterior margins; area larger than that of anal fin; anterior margin nearly straight; apices bluntly angular; posterior margin nearly straight; free rear tip angular, inner margin nearly straight. Claspers of adult male (non-type) moderately long, outer length 9.0% of TL, base 21.7 in outer length.

First dorsal fin relatively low, not falcate; anterior margin nearly straight to slightly convex, shallowly concave basally, apex moderately rounded; posterior margin slightly convex near apex then moderately concave, mostly angling slightly posteroventrally from apex; free rear tip acutely pointed, inner margin shallowly concave; origin over middle of pectoral-fin inner margin; midpoint of base 1.42 (1.29–1.53) times closer to pelvic origins than pectoral insertions; free rear tip just anterior to pelvic-fin origins by about half an eye length. First dorsal-fin base 1.84 (1.50–2.03) in interdorsal space, 2.69 (2.21–2.84) in dorsal caudal margin; height 1.10 (0.98–1.31) in base; inner margin 2.17 (2.13–2.21) in height, 2.37 (2.16–2.53) in base.

Second dorsal fin small, broadly triangular, not falcate; height 0.32 (0.34–0.37) second dorsal-fin height; base 0.57 (0.54–0.61) times first dorsal-fin base; anterior margin concave basally, becoming slightly convex distally; apex somewhat angular; posterior margin moderately concave; free rear tip acutely pointed, inner margin nearly straight; origin well behind pelvic-fin free rear tips and about opposite anal-fin origin; rear tip about opposite anal-fin free rear tip, in front of upper caudal-fin origin by 1.25 (0.81–0.99) times its inner margin length; posterior margin curving posteroventrally from apex; insertion slightly posterior to level with fin apex. Second dorsal-fin base 1.39 (1.11–1.33) in dorsal–caudal space; height 1.94 (1.61–2.07) in base; inner margin 1.19 (1.16–1.37) in height, 1.62 (1.36–1.71) in base.

Anal fin slightly falcate; height 1.05 (1.01–1.22) times second dorsal-fin height, base length 1.10 (0.93–1.12) times second dorsal-fin base; anterior margin slightly convex; apex moderately rounded; posterior margin deeply concave; free rear tip acutely pointed, inner margin nearly straight; origin opposite second dorsal-fin origin; insertion about opposite second dorsal-fin insertion, about level with fin apex; free rear tip in front of lower caudalfin origin by about its inner margin length; posterior margin almost vertical and then abruptly posterodorsally from apex. No preanal ridges obvious. Anal-fin base 1.14 (1.06–1.19) in anal–caudal space; height 2.03 (1.62–1.88) in base; inner margin 1.09 (1.03–1.05) in height, 1.86 (1.57–1.80) in base.

Caudal fin narrow-lobed and asymmetrical, with short terminal lobe and prominent, long, narrow, non-falcate 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 bluntly angular; lower postventral margin slightly convex; upper postventral margin nearly straight except for convex section at subterminal notch; subterminal margin nearly straight; terminal margin slightly concave and irregular, lobe formed by these margins angular, tip of tail narrowly rounded. Length of dorsal caudal margin 2.61 (2.61–2.90) in precaudal length, preventral caudal margin 2.85 (2.32–2.49) in dorsal caudal margin, terminal lobe from caudal tip to subterminal notch about 3.15 (3.24–3.37) in dorsal caudal margin, subterminal margin length 1.78 (1.69–2.01) in terminal margin.

Counts of total vertebral centra (TC) 130 (123–138), precaudal centra (PC) 62 (62–68), monospondylous precaudal (MP) centra (42–48), diplospondylous precaudal (DP) centra (20), diplospondylous caudal (DC) centra 68 (59–70); MP centra (32.6–35.8)%, DP centra (14.5–16.3)%, and DC centra (48.0–51.9)% of TC centra. Ratios of DP/MP centra (0.42–0.48), DC/MP centra (1.34–1.60). MP-DP transition often difficult to precisely locate, forming a`stutter zone' of alternating long and short centra.

Colour. Dorsal surfaces pale brownish when fresh, whitish ventrally and on lower sides. Demarcation between darker dorsal and paler ventral colours (waterline) extending from snout to upper margin of eye, then upper margin of posterior eye through upper level of gill slits to pectoral-fin base; from pectoral-fin insertion extending almost horizontally to about level with pelvic-fin origin, then extending vertically to about midlateral side and then about horizontally to upper two thirds of caudal peduncle; edge of waterline mostly diffuse, sharpest on head and tail. First dorsal fin without markings; second dorsal fin with a very distinct black apical blotch on upper third of fin, distinctly whitish below black blotch, very distinct from ground colour of fin; pectoral, pelvic, anal and caudal fins without markings (rarely with pale outer margins).

Size. Specimens examined in this study ranged from 373–736 mm TL. Moore et al. (in press) recorded more than a 1000 specimens from fish markets in Kuwait, Qatar and Abu Dhabi with males and females ranging from 360–960 mm TL and 360–1007 mm TL, respectively, with males maturing between 630 and 800 mm TL (L 50 = 721 mm TL). In this study, 8 pregnant females (790–1007 mm TL) were recorded, containing 2–5 late-term embryos between 320 and 387 mm TL. Thus size at birth is around 370–390 mm TL.

Distribution. Occurs in the western Indian Ocean from at least the Persian Gulf to India; full extent of range not known. An inshore species, most likely occurring in less than 100 m depth. Capture locations of examined specimens shown in Figure 4 .

Etymology. Müller & Henle described this species in 1839 and named it after Jean-Jacques Dussumier (1792– 1883), the collector of one of the syntypes (=a paralectotype) and a French voyager who collected a large number of zoological specimens in the Indian Ocean between 1816 and 1840.

Carcharhinus dussumieri Carcharhinus tjutjot

Other material (n = 3) Other material (n = 6) continued next page

Figures

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).

FIGURE 5. Lateral view of Carcharhinus dussumieri: A. lectotype MNHN 1135 (juvenile male 373 mm TL), preserved; B. CSIRO H 6957 – 01 (juvenile male 478 mm TL), fresh; C. not retained adult male ~ 800 mm TL (Sharq fish market, Kuwait City), fresh.

Tables

TABLE 2. Proportional dimensions as percentages of total length for the lectotypes of Carcharhinus dussumieri (MNHN 1135) and Carcharhinus tjutjot (RMNH 7382), and ranges and means for the other specimens and secondary types measured of both species.

Lecto. TOT (mm) 373 PRC 72.4 PD2 57.9 PD1 29.0 PD1 (horiz.) 27.8	Carcharhinus dussumieri Other material (n = 3) Min. Max. Mean 441 736 552 72.6 75.1 73.6 58.0 60.3 58.9 28.9 29.4 29.2 28.4 28.5 28.4	Lecto. 585 73.8 60.2 28.6 27.2	Carcharhinus tjutjot Other material (n = 6) Min. Max. Mean 342 712 545 72.5 74.6 73.3 57.2 60.4 59.0 26.8 30.2 28.4 26.4 29.7 27.7
HDL 23.3 HDL (horiz.) 22.9	23.5 24.4 23.9 23.2 24.2 23.6	22.7 21.6	21.1 24.5 22.6 20.1 24.1 21.9
PG1 17.5 PG1 (horiz.) 16.8 POB 7.6 POB (horiz.) 7.0	18.6 19.7 19.0 18.1 19.3 18.5 8.5 9.2 8.8 6.7 7.5 7.2	17.4 16.3 7.4 5.4	16.8 19.4 17.9 16.3 19.1 17.3 7.3 9.5 8.2 5.9 8.4 6.9
POR 6.8 PRN 5.1	7.1 8.1 7.4 5.2 5.7 5.4	5.8 4.3	5.6 8.2 6.9 4.5 5.9 5.0
PRN (horiz.) 4.3	4.3 4.8 4.6	3.5	3.6 5.1 4.2
PP1 22.9 PP2 45.8 SVL 47.7 PAL 57.9 IDS 18.9	21.4 23.8 22.9 44.2 47.6 45.9 46.7 49.3 48.2 56.1 59.9 57.8 17.9 20.8 19.6	22.9 43.4 - 58.5 20.8	20.3 23.7 21.7 43.7 46.2 45.4 45.5 48.4 47.2 56.6 59.1 57.6 19.4 22.0 20.5
DCS 8.1	7.8 8.4 8.0	8.7	8.2 9.8 8.7
PPS 20.2 PAS 7.9 ACS 7.4	18.6 21.2 19.8 6.7 7.2 7.0 7.2 7.9 7.5	21.9 8.1 6.9	19.3 21.9 20.3 6.3 8.9 7.6 7.2 9.3 8.2
EYL 2.6 EYH -	2.0 2.6 2.4 1.7 2.1 1.9	2.2 1.6	1.9 3.0 2.4 1.5 2.5 1.8
INO 8.9 NOW 1.5 INW 4.5 ANF 0.5	9.0 9.8 9.5 1.7 1.9 1.8 4.7 5.3 5.0 0.5 0.5 0.5	8.4 1.6 4.2 0.5	8.5 10.1 9.3 1.5 2.1 1.7 4.2 5.5 4.8 0.4 0.7 0.6
MOL 4.8 MOW 8.2	4.9 5.3 5.1 7.6 8.1 7.8	5.1 7.4	4.1 5.1 4.5 6.8 8.0 7.5
ULA 0.5 LLA 0.5 GS1 3.2 GS2 3.1	0.3 0.4 0.3 0.0 0.4 0.2 2.6 3.1 2.8 2.9 3.2 3.1	0.1 0.1 2.6 2.8	0.2 0.3 0.2 0.2 0.4 0.3 2.5 3.7 2.8 2.6 3.6 2.9
GS3 3.6 GS4 3.2	3.3 3.5 3.4 3.4 3.8 3.5	3.6 3.8	2.7 3.9 3.1 2.6 3.8 3.0
GS5 2.6 ING 6.0	2.6 3.2 2.9 5.0 5.6 5.3	3.1 5.6	1.8 3.2 2.4 4.9 5.9 5.2 continued next page