Orectolobus parvimaculatus Last & Chidlow, 2008, new species
Creators: name: Last, Peter R.
name: Chidlow, Justin A.
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Orectolobiformes
Orectolobidae
Orectolobus
Orectolobus parvimaculatus

description: Orectolobus parvimaculatus new species
(Figs 2, 3, 4, 6 A; Table 2)
Holotype. CSIRO H 5634–01, 885 mm TL, mature male, west of Perth, Western Australia, 31° 52′S, 115° 17′E, demersal gillnet, 87–107 m, 15 Nov. 2000.
Paratypes. 32 specimens: CSIRO H 5633–01, 876 mm TL, pregnant female (13 late-term embryos – CSIRO H 5633–02, 220 mm TL, immature male, CSIRO H 5633–03, 225 mm TL, immature male, CSIRO H 5633–10, 225 mm TL, immature male, CSIRO H 5633–11, 5 specimens, 225 – 235 mm TL, CSIRO H 5633– 12, 5 specimens, 208–222 mm TL; 6 juveniles from same mother (aquarium raised) – CSIRO H 5633–04, 629 mm TL, immature male, CSIRO H 5633–05, 630 mm TL, female, CSIRO H 5633–06, 593 mm TL, female, CSIRO H 5633–07, 565 mm TL, female, CSIRO H 5633–08, 631 mm TL, immature male, CSIRO H 5633– 0 9, 540 mm TL, female), south-west of Fremantle, Western Australia, 32° 17′S, 115° 14′E, caught by demersal gillnet, 88 - 108 m, 22 Nov. 2000; CSIRO H 6170–01, 910 mm TL, female, north-west of Perth, west of Lancelin, Western Australia, 30° 56′S, 114° 56′E, caught by demersal gillnet, 50 m, 0 6 Apr. 2003; CSIRO H 6171–01, 943 mm TL, female, CSIRO H 6172–01, 889 mm TL, mature male, southern Western Australia, caught by gillnet, 2002; CSIRO H 6188–01, 854 mm TL, mature male, south of Geraldton, north-west of Green Head, Western Australia, 29° 53′S, 114° 29′E, caught by demersal gillnet, 84 m, 17 Oct. 2004; CSIRO H 6192–01, 880 mm TL, female, CSIRO H 6192–02, 895 mm TL, female, south of Geraldton, west of Green Head, Western Australia, 29° 57′S, 114° 31′E, caught by demersal gillnet, 79 m, 16 Oct. 2004; WAM P 32871–001, 880 mm TL, female, south of Geraldton, west of Green Head, Western Australia, 30° 0 0′S, 114° 32′E, caught by demersal gillnet, 79 m, 15 Oct. 2004; CSIRO H 6505–01, 242 mm TL, female, CSIRO H 6505–02, 240 mm TL, female, Comet Bay, near Mandurah, Western Australia, 32° 26′S, 115° 41′E, caught by prawn trawler, 9 m, 0 1 Feb 2003; WAM P 27279–001, 706 mm TL, mature male, Shark Bay, Western Australia, 26° 54′S, 113° 0 0′E, caught by trawl, 130–135 m, 22 Aug 1979; WAM P 31770–001, 222 mm TL, immature female and 225 mm TL, immature male, Rottnest Island, Western Australia, c. 32° 0 0′S, 115° 36′E, 20 Nov 2000.
Other material. CSIRO H 5938–01, head only (no length data), female, north-west of Rottnest Island, Western Australia, 31° 54′S, 115° 25′E, 46 m, 28 Jun. 2001; CSIRO H 6187–01, 240 mm TL, immature female, CSIRO H 6187–02, 2 specimens, 210–223 mm TL, immature females, southwestern Western Australia, 2002.
Diagnosis. A small Orectolobus (to about 940 mm TL) with the following: coloration variable, rich, brownish, greyish and/or yellowish dorsal colour pattern overlain with dense coverage of pale irregular streaks and large, ring-like ocelli; dorsal fins with alternating dark and light marginal blotches suffused with pale reticulations; dark saddles on tail converging strongly toward ventral surface; ventral surface of trunk mainly uniformly pale; nasal barbel distinctly bilobed; postspiracular lobes well developed, thallate, distance across preorbital group 1.8–2.5 times interspace between preorbital group and postspiracular lobe (PO/PO– PS1), 5.6–8.7 times base length of anterior postspiracular lobe (PO/PS1); base of anterior postspiracular lobe 2.6–4.5 in its distance from postorbital group (PO–PS1/PS1), 1.4–2.6 in its distance from posterior postspiracular lobe (PS1–PS2/PS1); no warty tubercles on back or above eye; dorsal fins tall, upright in adult males; first dorsal-fin origin over mid pelvic-fin base; tip of pelvic fin below or slightly forward of insertion of first dorsal fin; interdorsal space 0.6–0.8 times anal-fin base length; anal-fin inner margin 0.5–0.7 of anal-fin posterior margin; teeth in upper jaw 21–22, medial row at symphysis of upper jaw absent; monospondylous centra 46–49; total vertebral centra 142–149.
Description. Body strongly depressed anteriorly and firm; trunk slightly depressed, deepest near pectoralfin insertions (over midtrunk in some paratypes); not tapering abruptly at pelvic-fin insertion, tail subcircular in cross-section, not strongly compressed near base of caudal fin. Head broad, somewhat oval in cross-section, with truncate to slightly convex anterior when viewed from above; strongly depressed, height at eye 7.3 (5.9–8.3)% TL; abdomen moderately elongate, pectoral to pelvic space 13.3 (14.4–17.0)% TL, 0.58 (0.63– 0.78) of head length; pelvic to anal space 3.55 (2.78–3.52) times anal-fin base; caudal peduncle rudimentary, caudal fin almost connected to anal-fin insertion, compressed slightly, broadly oval in cross section at analcaudal junction, height 1.14 (0.97–1.07) times width at second dorsal-fin insertion, 1.58 (1.39–1.62) times width at anal-fin insertion.
Snout short, narrowly rounded in lateral view, almost truncate to broadly convex in dorsoventral view; expanded above nostrils dorsally; preorbital pit present, connected to snout tip by a shallow groove at midline; apex not indented anteriorly (slightly indented in some paratypes); preoral length 0.7 (0.8–1.1)% TL, 15.1 (10.2–13.1) in mouth width; prenarial snout 1.10 (1.07–1.45) times eye length. Eyes dorsal on head, small, slit-like, length 2.1 (1.7–2.3)% TL, 10.9 (9.7–13.6) in head length, supraorbital crest elevated slightly over and behind eye, tubercle absent; subocular pockets well-developed, curved, their length slightly longer than eye; interorbit flat to weakly concave, inter-eye distance 3.43 (2.82–4.12) times eye length, 1.12 (1.06–1.14) times direct preorbital length, 0.77 (0.70–0.79) times direct prespiracular length, 2.19 (1.90–2.18) times spiracle length. Spiracles large, slit-like, oblique to horizontal axis, much longer than eye; anterior margin concave, well elevated above flattened posterior margin (sometimes appearing as a raised fleshy ridge); posterior margin almost flat to forming a slight depression leading into spiracle. Gill slits lateral on head; 2nd over origin of Holotype Paratypes
CSIRO n=6 Holotype Paratypes
CSIRO n=6 pectoral fin, 3rd to 5th above pectoral-fin base; last gill slit longest, 1.26 (1.16–1.40) times 4th, located well forward of midbase of pectoral fin; first 4 more or less equally spaced, 4th and 5th closer together; upper edge of slits becoming increasingly more dorsal from 1st to 5th. Mouth large, horizontally expanded, broadly arched, lower jaw slightly inferior, width 10.8 (9.7–11.4)% TL, 1.45 (1.34–1.52) in head width at eye; upper labial furrows originating at nostrils; lower labial furrows longer, almost connected at symphysis of lower jaw, length 0.53 (0.41–0.55) of mouth width; symphysial groove deep, well developed, length subequal to distance between lower labial furrows. Teeth unicuspid, pointed, widely spaced, central cusps not flanked by small lateral cusps; largest near symphysis, 2 enlarged canines in upper jaw, 3 in lower jaw, these teeth about twice length of those adjacent; 21 (21–22, n=6) rows in upper jaw, 19 (17–19) in lower jaw; very small near jaw angle, sometimes acuspid; outer anterior pair of teeth of upper jaw exposed when mouth closed; no rudimentary symphysial canines in upper jaw. Nostrils small, widely separated, internarial space 5.0 (4.4–5.1)% TL; adjacent upper lip of mouth; posterior lobe well developed, forming an expanded tube-like flap. Nasal barbel terminal on head, digitiform, its base flattened, but becoming almost rounded and tapering distally; enlarged, broad-based, flattened, weakly thallate or bifurcate, anterolaterally directed lobe near its midlength; barbel length slightly shorter than upper labial furrow, 3.5 (2.8–3.7)% TL. Dermal lobe band well developed; PO1 with 3–5 (mainly 4), slender, slightly flattened, mainly simple lobes, first and last usually longer than those between; PO2 commencing near jaw angle, with 3 (3-6 in paratypes) slightly larger, more flattened, complex lobes, simple, bi or trilobed (but mainly multilobate); PS1 very broadly thallate with deeply incised outer margin (often weakly bi-lobate), base usually preceded by short, ridge-like, but well-developed lateral skin fold; PS2 thallate, similar in size or slightly smaller than PS1, mainly weakly trilobate; PO distance 1.93 (1.76– 2.48) times PO–PS1 interspace; PO distance 8.70 (5.55–6.72) times PS1 base length; PO–PS1 interspace 4.52 (2.60–3.81) times PS1 base length; PS1–PS2 interspace 2.56 (1.39–2.22) times PS1 base length.
Dermal denticles on flank minute, tight packed and sometimes imbricate, skin velvety; pedicel short, strong; crown short, arrowhead-shaped, with elevated posterior median ridge; on head and around spiracle crowns more irregular, posterior apex blunt, anterior margin crenulate; innermost denticles of spiracle greatly elongate, bristle-like; no crest of enlarged denticles at base of caudal fin. Clasper elongate, expanded slightly distally, cartilage at glans opening sharp-edged.
Dorsal fins of mature males similar in shape, stiff, subtriangular, upright, first distinctly larger than second, height of first 1.39 (1.20–1.38) times height of second, with almost straight anterior margins (paratypes less than 64 cm with relatively lower, less upright fins with weakly convex anterior margins and more rounded apices); apices narrowly rounded to bluntly pointed in adults; posterior margins straight to slightly concave; inner margin usually parallel to dorsal surface with free rear tip angular (first dorsal-fin rear tip of holotype damaged slightly); first dorsal-fin origin over mid pelvic-fin base, second originating well behind rear tip of pelvic fin; first dorsal-fin inner margin 1.22 (0.89–1.30) times spiracle length. Pectoral fin large, base fleshy, length 14.6 (14.3–16.6)% TL; anterior margin almost straight (slightly convex in immature paratypes), 3.14 (3.45–3.79) times inner margin; apex bluntly pointed (narrowly rounded in immature paratypes), posterior margin slightly s-shaped in adults (weakly convex in immature paratypes); inner margin mostly strongly convex, free rear tip broadly rounded. Pelvic fins enlarged, length 14.9 (13.1–14.3)% TL; anterior margin weakly convex, apex broadly rounded; posterior margin weakly to moderately convex; inner margin almost straight in adult males (strongly convex in other paratypes), free rear tip angular (broadly rounded in females and juvenile paratypes); pelvic-fin origin well forward of dorsal fins, origin to midpoint of first dorsal fin 9.7 (7.3– 9.5)% TL. Anal fin strongly raked, elongate, lobe-like, well developed; base short, length 6.6 (6.3–7.7)% TL, 0.92 (0.63–0.82) in interdorsal space; posterior margin almost vertical; origin well behind insertion of second dorsal-fin but usually forward of its free-rear tip, anal-fin height 1.90 (1.87–2.25) in base length; anal-fin length 2.29 (2.37–3.46) times posterior margin length; inner margin length 0.68 (0.54–0.71) of posterior margin length. Caudal fin relatively elongate, dorsal caudal margin length 19.0 (18.5–21.2)% TL; origin of upper lobe rarely abrupt; lower lobe well developed, outer margin very strongly convex, united at its origin to insertion of anal fin, deeply notched at junction of terminal lobe; terminal lobe deep, outer margin irregular, expanded, length 1.79 (1.38–1.77) times spiracle length.
Spiral valve counts 26–28 (n=6, based on discarded non-type specimens). Vertebral counts, n=11: holotype (10 paratypes): monospondylous centra 49 (46–49); precaudal centra 99 (98–103, 4 individuals less than 100); caudal centra 45 (43–48); total centra 144 (142–149, 4 individuals less than 145).
Coloration. Adult male holotype: dorsal surface yellowish brown with darker brown saddles and blotches suffused with white or bluish white ocelli, reticulations and spots. Head brownish with dense array of fine bluish spots forward of spiracle; indistinct darker brown bars across interorbit from hind half of eye, similar anteroventral bar below eye; dark brown saddle extending over head between spiracles and gill slits; gill membranes dark brown; dark blotches interspersed with white are lateral on head forward of gill membranes; dermal lobes white, often with dusky areas dorsally; very distinctive, large white blotch at posterior edge of spiracle; mid-dorsal region above gills with about 10 large, bluish white ocelli; ocellate markings thin, irregular in shape, similar in size to orbit, occurring more or less bilaterally. Trunk similar to head; two large stellate saddles on midline forward of first dorsal fin, each containing a pair of large ocelli, surrounded by smaller bluish white markings; pale areas between saddles with similar sized ocelli (these define edges of saddles); posterior saddle on dorsolateral surface of similar size and shape; small dark blotch before first dorsal fin. Precaudal tail with 3 irregular dark saddles, below mid-posterior regions of first and second dorsal fins (extending onto fins near their bases) and above anal fin; smaller large lateral blotch between dorsal fins; blotches encroached by ocelli dorsally, by white areas ventrally. Caudal fin with 2 smaller saddles, mottled with brown and white markings; dorsal fins similar to caudal fin; upper surfaces of pectoral and pelvic fins mottled with small blush white ocelli and blotches, and whitish areas; anal fin mostly white with dusky area near anterior margin. Undersurfaces of head, trunk and fins almost uniformly creamish or whitish; posterior halves of paired fins almost uniformly dusky. Claspers almost uniformly white; lips and mouth whitish. Another adult male (paratype CSIRO H 6172–01) has similar pattern to holotype but is greyish brown rather than yellowish brown; adults exhibit extreme variability in the shape of ocelli and associated reticulations.
Female paratypes CSIRO H 5633–05 (630 mm TL) and WAM P 31770–001 (222 mm TL): base pattern similar to holotype, but markings extremely variable in shape; coloration mainly yellowish or greenish, more strongly contrasted, and white ocelli and markings paler than adult male holotype and other large types; saddles and darkest markings more pronounced, often almost brownish black (particularly strong in neonatal juveniles); ventral surface penetrated laterally by tips of dark saddles (but not forming broad bands around tail); ventral surface of pectoral and pelvic fins with dark spots and blotches in early juveniles and immatures, when markings present in adults evident as a white base and dark distal half of fin.
Size. Small wobbegong shark, reaching at least 943 mm TL. Males mature by 706 mm TL; largest mature male 889 mm TL, largest immature male 631 mm TL; largest female 943 mm TL, pregnant female 876 mm TL. Smallest early postnatal juvenile about 208 mm TL.
Distribution. Inner continental shelf off southwestern Australia from Shark Bay (26° 54′S, 113° 0 0′E) to Mandurah (32° 26′S, 115° 41′E) in depths of 9– 135 m.
Etymology. Derived from a combination of the Latin parvus (little) with the name of a larger, congener with a similar, spotted colour pattern, Orectolobus maculatus, with which this species has been confused in the past.
Vernacular. Dwarf Spotted Wobbegong.
Comparisons. Orectolobus parvimaculatus is likely to have been confused in the literature with its larger congener, O. maculatus (e.g. Whitley, 1964; Compagno, 1984, 2001; Last and Stevens, 1994; Compagno et al. 2005; Hoese et al., 2006). Four nominal orectolobid taxa, Squalus appendiculatus Shaw in Shaw & Nod- der, 1806, S. barbatus Gmelin, 1789, S. lobatus Bloch & Schneider, 1801, and S. wattsii Meyer, 1793, are considered to be synonyms of O. maculatus (Compagno, 2001, Eschmeyer, 2007). Types of all four are unknown (Eschmeyer, 2007) and their descriptions are poor so we cannot easily determine their relationships to O. parvimaculatus and O. maculatus. However, because they were all collected from Port Jackson (New South Wales) and well outside the distributional range of O. parvimaculatus (considered endemic to Western Australia), they are most likely to be synonyms of O. maculatus.
The colorations of O. parvimaculatus and O. maculatus, which consist of a complex pattern of blotches overlain with pale rings and ocelli, are confusingly similar. However, O. parvimaculatus (reaching 94 cm, males mature at about 71 cm or smaller) is a much smaller shark than O. maculatus (reaching about 320 cm). Compagno (1984) reported that males of O. maculatus may mature at about 60 cm but this observation is likely to be based on males of O. parvimaculatus. Similarly, published distributional information for O. maculatus is probably incorrect because of the confusion between the two species. Based on current knowledge, O. maculatus is known to occur commonly off coastal eastern Australia (south to at least Eden, New South Wales), but it is also thought to occur in lesser abundances off southwestern Australia (Chidlow and McAuley, pers. comm.). Its distribution between these regions is uncertain and needs validation. Neither species has been confirmed from Tasmania.
Orectolobus parvimaculatus differs subtly from O. maculatus in colour pattern but no other wobbegongs have a similar pattern of pale rings or ocelli on the dorsal surface. Orectolobus parvimaculatus have relatively larger and more densely distributed ocelli that incise more deeply into the margins of each dark dorsal saddle (saddles appear stellate rather than subrectangular, see Figs 2 B and 5B), dorsal fins with blackish marginal blotches (dark markings absent in O. maculatus), dark saddles on the tail converge strongly ventrally (almost triangular in lateral view but do not extend around the ventral surface as a broad band, see Fig. 6), a less welldeveloped dark predorsal blotch, and ocelli are present between the eyes and extend onto the snout (present only as pale flecks in O. maculatus). Also, adult O. parvimaculatus have much taller, more upright dorsal fins than O. maculatus of equivalent size, slightly smaller and more densely packed denticles with shorter pedicels (skins appears rougher in O. maculatus), possibly marginally more deeply incised margins of the postspiracular dermal lobes, lack a small tubercle above the posterior half of the eye (present in O. maculatus); and fewer vertebrae (monospondylous centra 46–49 vs. 49–54, total centra 142–149 vs. 152–153).
Orectolobus parvimaculatus also differs from the other new wobbegong described in this pape r, O. fl ori - dus, by the following: ventral surface uniformly pale (rather than yellowish brown with dark blotches and spots); dermal lobes of head well developed (rather than poorly developed), distance across preorbital group 1.8–2.5 (rather than 1.2–1.4) times interspace between preorbital group and postspiracular lobe, base of anterior postspiracular lobe 2.6–4.5 (rather than 9–12) times in its distance from postorbital group, 1.4–2.6 (rather than 5–6) times in its distance from posterior postspiracular lobe; dorsal fins tall and upright in adult males (rather than low and raked); interdorsal space 0.6–0.8 (rather than 0.3–0.4) times anal-fin base length; and anal-fin inner margin 0.5–0.7 of (rather than 1.1–1.2 times) anal-fin posterior margin.
Within its known distribution, O. parvimaculatus differs from congeners O. hutchinsi and O. wardi in having a more complex complex colour pattern and dermal lobe arrangement (3–6 simple or divided lobes vs. 2 simple or weakly divided lobes in the preorbital groups of each of the other species). Orectolobus halei has a complex dermal lobe arrangement but has a much different colour pattern. Eucrossorhinus dasypogon has a broader head with an even more complex arrangement of dermal lobes, and Sutorectus tentaculatus has a much simpler dermal lobe arrangement and rows of warty tubercles extending along the middle of the head and back (absent in O. parvimaculatus).
Compagno (1984) reported that O. maculatus have large litters with one female having 37 young. He records the birth size of the species at about 21 cm TL. The frozen carcass of a pregnant female O. parvimaculatus (CSIRO H 5633–01) released 13 late-term embryos (208–225 mm TL). Another 6 specimens born just before her death survived for more than a year in captivity and reached about 600 mm TL. The birth size of young O. parvimaculatus is consistent with the reported birth size of O. maculatus, but O. parvimaculatus is likely to have much smaller litters due to its smaller overall size.
Orectolobus parvimaculatus exhibits obvious sexual and ontogenetic variability. Adult males are more reddish brown and have ocelli that are bluish white, rather than white or yellowish as in females and immature males. Adult males and females have much taller more upright fins than small individuals.
Comparative material. Orectolobus maculatus: CSIRO CA 3658, female 566 mm TL, Cronulla, NSW, 1983; CSIRO H 5765–01, immature male 242 mm TL, CSIRO H 5766–01, female 400 mm TL, Southport, QLD, 2001; CSIRO H 6190–01, immature male 711 mm TL (ex Manly Aquarium, born in aquarium in Jan 2002 and died in Jan 2004).
description: Published as part of Last, Peter R. & Chidlow, Justin A., 2008, Two new wobbegong sharks, Orectolobus floridus sp. nov. and O. parvimaculatus sp. nov. (Orectolobiformes: Orectolobidae), from southwestern Australia, pp. 49-67 in Zootaxa 1673 on pages 56-66, DOI: 10.5281/zenodo.274050