Orectolobus ornatus De Vis, 1883

Charlie Huveneers, 2006, Redescription of two species of wobbegongs (Chondrichthyes: Orectolobidae) with elevation of Orectolobus halei Whitley 1940 to species level., Zootaxa 1284, pp. 29-51 : 43-48

Orectolobus ornatus De Vis, 1883

(Figs. 7-9, Table 1-2)

Material examined

Holotype. QM I 164, 560 mm TL, female, type locality: Moreton Bay, registered 5th of December 1911.

Other specimens. Five specimens: AMS I 43621-001, 890 mm TL, mature male ; AMS I 43628-002, 890 mm TL, mature male ; AMS I 43628-003, 876 mm TL, mature male ; AMS I 43628-004, 925 mm TL, mature male ; AMS I 43628-005, 905 mm TL, mature male. All specimens caught together in 5-10 m of water, 10-15 m off northern tip of Tomaree Head, Port Stephens, NSW, 32° 43S, 152° 11E. Collector Charlie Huveneers, Rob Harcourt and Roger Laird on the 7th and 8th of May 2005.

Diagnosis

A small Orectolobus species with the following combination of characters: no warty tubercles on head or body; four groups of dermal lobes below and in front of the eyes on each side of head; no dermal lobes on chin; nasal barbel closest to mouth branched; three lobes at second preorbital group (rarely four) with first and last lobes branched and longer than middle one; broad unbranched postspiracular groups; lack of supraorbital knobs; base of anterior postspiracular lobe 2.19-3.56 in its distance from postorbital group, 1.19-2.11 in its distance from posterior postspiracular lobe; pelvic-fin insertion anterior to first dorsal-fin midpoint; prepelvic length 1.78-2.22 times pelvic-anal space; pelvic-caudal space 1.52-1.95 times trunk width; teeth in upper jaw 23-27, those in medial row at symphysis rudimentary; spiral valve turns 20-23; precaudal vertebrae count 98-104. Brownish, greenish and grayish coloration with eight darker brown blotch-shaped saddles located dorsally; small light brown, freckle-like blotches between saddles.

Description

Body depressed anteriorly from snout to first dorsal fin origin, firmness of body unknown as holotype is a dry mount but other examined specimens have slightly firm dorsal musculature with relatively flaccid flanks; trunk depressed, broadest over midtrunk; body shape changing from depressed to compressed and tapering from pelvic-fin midpoint; dorsal musculature slightly elevated from flank musculature forming a small ridge from the fifth gill slit to pelvic-fin insertion, decreasing anteriorly to first dorsal-fin origin. Head broad, strongly depressed, somewhat oval in cross-section with truncate anterior when viewed from above, length 20.8 (19.3-20.8) % TL, 1.79 (1.61-1.79) times second dorsal-fin origin to anal-fin origin, height at gill level 8.9 (7.9-8.9) % TL, 0.77 (0.77-1.06) in pelvic-fin midpoint to first dorsal-fin insertion; trunk width 17.4 (16.9-18.7) % TL; abdomen elongate, width 5.5 (5.3-5.7) % TL. Pectoral-pelvic space 18.0 (15.4-18.2) % TL, 0.86 (0.74-0.92) times head length; pelvic-anal space 3.24 (2.58-3.24) times anal-fin base; snout-vent length (0.81-0.91) times vent-caudal length. Caudal peduncle absent, lower origin of caudal fin almost connected to anal-fin insertion, strongly compressed, oval in cross section at anal-caudal junction, caudal peduncle width 0.71 (0.71-1.56) times height.

Snout short, narrowly rounded in lateral view, truncate in a semi-hexagonal shape in dorsoventral view; preoral length 1.5 (1.0-1.5) % TL, 5.88 (5.88-10.00) in mouth width; prenarial length negligible. Eyes dorsal on head, small, slit-like, length 1.7 (1.6-2.0) % TL, 12.5 (10.00-12.50) in head length; supraorbital crest elevated over and behind eye; no supraorbital knob; ridge extending supraorbital crest above spiracle terminating slightly behind spiracle, terminating above spiracle in other specimens examined; supraocular crest absent in holotype, moderate in size in other specimens examined; interorbit flat to weakly convex, 3.89 (3.07-4.04) times eye length. Spiracles slit-like, oblique to horizontal axis, longer than eye, 1.56 (1.43-1.76) times eye length; anterior margin convex well elevated above concave posterior margin; small eye spiracle space 0.5 (0.3-0.7) % TL; fold above spiracle absent. Gill slits lateral on head, first three of similar length (1.6-2.1 % TL), fourth gill slit smaller, 0.91 (0.82-0.92) times second gill slit, last gill slit longest, 1.38 (1.18-1.46) times second, last gill slit anterior to pectoral-fin midbase; pectoral-fin origin between second and third gill slit. Mouth subterminal, large 2.2 (2.2-2.6) % TL, horizontally expanded, broadly arched, width 8.1 (8.1-9.1) % TL, 3.35 (3.35-3.81) times its length, 1.59 (1.49-1.59) in dorsal-fin midpoint to pelvic-fin origin; upper labial furrows 3.9 (3.6-4.0) % TL originating at ventral margin of nostrils; lower labial furrows longer 4.8 (4.2-4.6) % TL, 1.09 (1.07-1.17) times upper labial furrows, almost connected to symphysis of lower jaw. Nostrils small, widely separated, internarial space 4.4 (4.4-5.1) % TL, adjacent upper lip of mouth. Nasal barbel terminal on head, medial to nostrils, proboscis-like, rounded basally, tapering distally, length subequal to upper labial furrows; short flattened unbranched lobe at basal third of posterior margin; lateral nasal lobe broad well elevated, subcircular, most expanded posteriorly.

Fang-like teeth relatively large, long and pointed, not exposed when mouth closed. Upper jaw with rudimentary symphysial tooth recessible into upper lip and flanked distally by one larger symphysial on either side. Lower jaw with three rows of enlarged symphysials, their cusps subequal in length to each other and to those at symphysis in upper jaw; tooth cusps distal to symphysis decreasing sequentially in size; tooth shape varies distally from symphysis, first two to three teeth lack cusplets, one to two cusplets from the third or fourth parasymphysial on either side of the cusp on about four to seven teeth, distal cusplets more pronounced than medial ones, three to five most distal teeth generally lack cusplets on either side of cusp; teeth formula (n = 12): upper jaw (10-12) +1 + 1 + 1 + (10-12) = (23-27); lower jaw (7-9) + 3 + (7-9) = (18-21).

Dermal lobes well developed; anterior preorbital group with two to three simple lobes, posterior lobe longest; posterior preorbital group with three lobes, anterior and posterior lobe longer and branched; combined distance across preorbital groups 6.7 (6.1-7.9) % TL; anterior and posterior postspiracular group with short, broader, unbranched single lobe, base width of anterior postspiracular lobe 1.1 (1.1-1.3) % TL, base width of posterior postspiracular lobe 0.9 (0.9-1.2) % TL; distance between prorbital group and anterior postspiracular lobe 3.8 (3.5-4.8) % TL, between postspiracular lobes 2.6 (1.5-2.6) % TL.

Dermal denticles small, non-imbricated, crown shield-like, weakly tricuspidate at anterior end, weak ridge on all cusps at anterior end, rounded posterior end. Clasper elongate, extending well beyond tip of pelvic fins, inner length of mature male 14.6-15.6 % TL, (3.91-5.06) times width at base, tip bluntly pointed; four terminal cartilages: ventral terminal, accessory terminal cartilage (or spur), dorsal terminal 2 and dorsal terminal, approximate one-to-one ratio with all terminal cartilages, end-style of axial cartilage slightly calcified and fused with dorsal terminal. When terminal cartilage of clasper is open, spear-like extension near lateral side of axial 16.9 (14.5-19.5) % clasper shaft length.

Dorsal fins similar in size and shape, triangular; anterior margins oblique; apices broadly rounded; posterior margins vertical, very slightly convex to straight; inner margin parallel originating behind pelvic-fin rear tip; second dorsal-fin height 6.3 (6.3-8.0) % TL, 0.43 (0.43-0.59) times pelvic-fin midpoint to second dorsal-fin origin; pre-first dorsal fin 50.0 (48.7-50.3) % TL, pre-second dorsal fin 64.5 (61.6-64.5) % TL; first dorsal-fin origin slightly forward to pelvic-fin insertion (1.6 % TL); second dorsal-fin insertion slightly anterior to anal-fin origin 1.9 (1.8-3.0) % TL.

Pectoral fin large, length 12.7 (12.2-13.6) % TL, 2.48 (2.40-2.74) times pelvic-fin inner margin length; unknown fleshiness of base due to preservation but fleshy base in other specimens examined; anterior margin slightly convex; apex broadly rounded; posterior margin slightly convex; inner margin straight, free rear tip very broadly rounded; prepectoral length 17.3 (15.3-19.1) % TL; pectoral-pelvic space 17.9 (15.4-18.2) % TL.

Pelvic fins moderately large, length 11.0 (11.0-14.5) % TL; anterior margin straight; apex very broadly rounded; posterior margin convex; inner margin straight, free rear tip broadly rounded; origin anterior to first dorsal-fin origin, insertion anterior to first dorsalfin midpoint; prepelvic length 42.5 (39.6-43.5) % TL, 1.85 (1.83-2.22) times pelvic-anal space; pelvic-anal space 23.8 (19.6-23.8) % TL, pelvic-caudal space 30.1 (28.1-31.4) % TL, 1.73 (1.52-1.85) times trunk width.

Anal fin elongate, lobe-like, well developed, base 7.1 (7.2-8.6) % TL, 1.37 (1.37-2.15) times interdorsal space; anterior and inner margins almost parallel, anterior margin first slightly concave then slightly convex; apex very broadly rounded; posterior margin straight, much smaller than anterior margin; inner margin straight, free rear tip slightly rounded; origin slightly posterior to second dorsal-fin insertion; anal-fin height 2.27 (1.49-2.44) times base length; second dorsal-fin origin to anal-fin origin 11.1 (11.6-12.4) % TL; second dorsal-fin insertion to anal-fin insertion 1.74 (1.74-2.04) times terminal caudal margin.

Caudal fin long, strongly compressed; dorsal caudal margin length 21.2 (20.3-21.9) % TL. its origin slightly anterior to anal-fin insertion; upper lobe originating as a very low ridge, slightly distinguishable, anterior margin with a deep inflexion near its origin; outer rim straight and oblique; rounded apices; terminal caudal lobe fan-like; terminal caudal margin 4.1 (4.1-5.1) % TL.

Vertebral counts (n = 10): pre-first dorsal count 46-51; pre-second dorsal count 69-74; precaudal count 98-104. Spiral valve whorl count: 20-23 (n = 22, based on discarded specimens).

Coloration

Body brownish, greenish, and grayish with eight darker brown, blotch-shaped saddles located dorsally; light brown freckle-like blotches between saddles; first saddle broader than long, posterior to spiracle, anterior to first gill slit, symmetrical from dorsal midline; second saddle at pectoral-fin base level, broader than long; posterior end of third saddle at pelvic-fin origin level, length similar to width, lighter brown green saddle extending laterally; fourth saddle small, lighter brown, anterior to first dorsal-fin origin, overlapping with inflexion of first dorsal fin; fifth saddle from first dorsal-fin midbase to slightly anterior to second dorsal-fin origin, extending laterally and ventrally below mid body, nearly connecting at ventral midline; sixth saddle from second dorsal-fin midbase to slightly anterior to caudal-fin origin, extending laterally and ventrally, nearly connecting at ventral midline; seventh saddle at origin of caudal fin, anterior to anal-fin insertion, longer than broad, extending laterally, not extending on lower lobe of caudal fin; eighth saddle on upper caudal lobe, longer than broad, extending laterally, not extending on lower lobe of caudal fin; green gray blotches on saddles decreasing in number and size from snout to caudal fin. V-shaped pattern anterior to interorbit; white spot on posterior tip of spiracle.

Underneath of head, trunk and abdomen uniformly yellow green. Tail with three darker brown stripes on the flanks.

Pectoral fins light and dark brown with blotches and white freckles, underneath uniform yellow with white spots; pelvic fins light and dark brown with blotches and white freckles, underneath yellow at base, increasing brown green color towards posterior margins, slight blotches; anal fin gray brown, similar to tail coloration; dorsal fins light and dark brown with blotches and white freckles and darker brown where saddles occur; caudal fin brown green, darker brown where saddles occur.

Remarks

Orectolobus ornatus was previously considered to be juvenile O. halei due to its similarity in morphology and color pattern. It can be distinguished from O. halei by several measurements (Table 1) and also differs in 11 specific ratios (Table 2).

Orectolobus ornatus is also sympatric with O. maculatus and O. wardi and can be easily distinguished from them by the number of supraorbital knobs and dermal lobes, and the color pattern. Orectolobus maculatus and O. wardi have one or two supraocular knobs, whereas these knobs are absent in O. ornatus (Goto 2001). Orectolobus maculatus has six to ten dermal lobes, O. wardi has unbranched nasal barbels, whereas O. ornatus has five dermal lobes and branched nasal barbels. Orectolobus wardi has a simple color pattern with few dark spots while O. maculatus and O. ornatus have more elaborate variegated spots and saddles. Orectolobus maculatus has white rings that are absent in O. ornatus .

Size

To at least 1017 mm TL; males mature between 796-830 mm TL, females mature between 795-864 mm TL (Huveneers 2005 unpublished data).

Distribution

Eastern Australia from Port Douglas (16° 32S, 145° 29E), Qld , to Sydney (151° 23E, 33° 36S), NSW .