Gollum suluensis Last & Gaudiano, 2011, sp. nov.
Creators: name: Last, Peter R.
name: Gaudiano, Joe P.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Elasmobranchii
Carcharhiniformes
Pseudotriakidae
Gollum
Gollum suluensis

description: Gollum suluensis sp. nov.
(Sulu Gollumshark)
Figs 1–7; Table 1
Gollum sp. A: Compagno et al., 2005a: 258, Pl 42. Gollum sp. 1: Compagno et al., 2005b: 29.
Gollum sp. (suluensis): GBIF, 2006, listed.
Gollum suluensis: GBIF, 2006, listed (nomen nudum).
Holotype. PNM 15175 (formerly SUML JPAG 235), adult male 585 mm TL, collected Liberty landing site, Bagong Sikat, Puerto Princesa City (Palawan, Philippines), caught by hook and line off Puerto Princesa Bay, Sulu Sea, depth ~ 730 m, 16 March 2000.
Paratypes. 5 specimens collected with holotype: CSIRO H 7193–01 (formerly SUML JPAG 229), immature male 575 mm TL; PNM 10294 (formerly SUML JPAG 237), adult male 584 mm TL; and SUML JPAG 230, 233, PNM 10295 (formerly SUML JPAG 234), females 534–652 mm TL.
Diagnosis. A small species of Gollum with the following combination of characters: body soft; head bellshaped with a broadly parabolic snout; direct preorbital snout length 2.1–2.4 times eye length; preoral length 0.8–1.0 of mouth width, 1.3 times prenarial length; eye 1.4–1.5 times nostril length, more than 4.8 times spiracle length; head relatively broad, 12–14% TL; direct preorbital snout length 1.2–1.4 times interorbital space; head length 2.3–2.6 times mouth width, 8.0–9.0 times nostril width, 3.0–3.5 times preventral caudal-fin margin; length of pectoral-fin anterior margin 2.2–2.5 times its base; first dorsal-fin inner margin 0.5–0.6 of pectoral-fin base; second dorsal-fin base 10–12% TL; ventral head dusky, not strongly contrasted with dorsal surface along its lateral margin; posterior edges of dorsal fins not excessively concave; tips of dorsal fins dark; ventral margin of caudal fin dusky, not strongly contrasted with rest of fin; mouth dark; monospondylous centra 44–45, diplospondylous centra 107–109, total centra 151–154.
Description. Body moderately elongate, trunk slender; vertically oval in cross-section at first dorsal-fin base; caudal peduncle slender, subcylindrical, barely tapering. No predorsal or interdorsal ridges, or lateral ridge keels or precaudal pits. Head relatively broad, depressed, spatulate, long, 0.91 in holotype (1.02–1.10 in paratypes) in pectoral-pelvic space; outline in lateral view narrow, more so forward of nostrils, snout upturned slightly at tip; outline in dorsoventral view, parabolic in prenasal region, deeply indented at nostrils then weakly convex to branchial region. Preoral snout elongate, its length 0.96 (0.82–0.91) in mouth width. Snout tip bluntly pointed in lateral view, prenasal concave above and weakly concave below, nape almost flat with a shallow median groove. Eyes large, elongate oval, length 6.07 (5.62–6.05) in head length, 2.24 (2.4–3.47) times eye height; dorsolateral on head, with lower edge partly sunken below subocular ridge in lateral view; their external opening without notches; subocular ridges very well developed; almost on horizontal alignment with snout margin at nostrils. Spiracles small, length 5.50 (4.81–10.25) in eye length, 0.55 (0.29–0.71) of distance from eye to spiracle. Gill openings short, margins irregular, well separated, gill filaments not visible externally; their upper ends at level of or slightly above lower edge of eye, not becoming more elevated distally; first four gill openings subequal in width, fifth shortest; width of first 1.36 (1.18–1.50) times width of fifth, 0.41 (0.40–0.56) of eye length. Nostrils with pronounced suboval incurrent apertures, lacking posterolateral keels; positioned well forward of mouth, prenarial distance 0.76 (0.75–0.79) of preoral distance; nasal flaps well-developed, bluntly subtriangular, with irregular, narrowly rounded apices; excurrent apertures moderate elongate to oval, slightly smaller than incurrent apertures; posterior nasal flaps short, flattened, semicircular, partly concealed; nostril width 1.47 (1.47) in internarial space, 1.41 (1.40–1.50) times in eye length, 1.71 (1.20–1.76) times first gill opening width.
Mouth large, very angular, rather elongate; width about 0.74 (0.65–0.81) of head width at gill slits, 2.59 (2.26–2.46) times in head length; lower jaw angle below anterior margin of eye; symphysis of upper jaw below anterior margin of eye; labial furrows relatively short, their length irregular, uppers about half length of lowers (closer to subequal in some paratypes), uppers extending to below hind margin of eye (forward of hind margin in paratypes). Tongue enlarged, flat, rounded-angular apically, filling most of floor of mouth; no large buccal papillae on floor or roof of mouth; palate and floor of mouth largely naked, without buccopharyngeal denticles. Teeth very small and numerous, pungent; in ca 94 rows in upper jaw, ca 81 rows in lower jaw, 4–5 series functional in adult male holotype; posterolateral teeth arranged in conspicuous diagonal rows in both jaws; no toothless spaces at symphysis; teeth moderately differentiated in upper and lower jaws and along jaws; medial tooth rows larger than lateral rows. Sexual heterodonty very weak, adult male holotype with slightly taller cusps than adult female paratype (SUML JPAG 233). Upper jaw teeth multicuspidate, mainly with 3–5 cusps; outer medial teeth directed posteriorly, inner teeth recurved, directed toward roof of mouth, with higher crowns and longer-cusps than rows at angle of jaw or in labial rows of lower jaw; medial teeth tall with erect or semi-erect primary cusps, and 1–2 smaller cusps on either side of primary cusp; outermost cusps minute, pungent; mid-lateral cusp usually much longer than outermost cusp but less than half the length of the median cusp near symphysis; mid-lateral cusp only slightly shorter than the median cusp at the angle of the jaw; teeth at symphysis with slight shorter median cusps than those adjacent; adult female paratype with extremely reduced cusps at angle of jaw, appearing as serrate ridge. Lateral teeth in both jaws more bladelike than medial teeth. Lower jaw teeth in a broad band at symphysis; innermost medial teeth strongly recurved, directed lingually, with longest central cusps in lower jaw; length of central cusp in relation to lateral cusps diminishing progressively toward angle of jaw; teeth near angle of jaw with 2–4 short anterior cusps in a linear row (their length usually increasing in size slightly posteriorly) and an additional posterior cusp projecting laterally from this row.
Lateral trunk denticles with long, slender pedicel and flat, elevated, sub-circular to teardrop-shaped crown. Crown horizontal to slightly erect, mostly less than twice as long as wide; with a strong medial ridge extending entire length of the crown and forming a strong medial cusp posteriorly; medial cusp subequal in length to rest of the crown; lateral cusps present, length variable, usually short and broad, lateral ridges poorly developed or absent; crowns weakly to moderately well imbricated; interspaces between denticles particularly evident when body twisted. Prominent ridge of enlarged denticles along dorsolateral margin of caudal fin, extending from its origin and covering more than half of dorsal caudal margin; median denticles of ridge with smooth crowns, acuspid to weakly cuspid, in 3–4 irregular rows, subequal in size to typical tricuspidate denticles of caudal fin; single row of greatly enlarged, semicircular, smooth-crowned, acuspid denticles arranged along ridge margin and bordering smaller median denticles; these enlarged denticles directed laterally, 3–4 times larger than caudal denticles below; narrow groove of naked skin separating these denticles and main caudal denticles; a few broad, leaf-shaped, recurved denticles distributed in this groove; ridge and associated enlarged denticles most obvious directly above apex of ventral caudal lobe.
Pectoral fins rather broad and subtriangular, not falcate, almost twice area of first dorsal fin; located near ventral surface; with moderately convex anterior margins, narrowly rounded apices, weakly concave posterior margins, broadly rounded free rear tips, moderately convex inner margins, and narrow bases; anterior margin length 2.32 (2.21–2.54) times base length. Origins of pectoral fins under fourth gill openings; apices opposite their free rear tip when fin elevated and adpressed to body, adjacent origin of first dorsal fin. Pelvic fins small, narrowly triangular; length of anterior margin 0.40 (0.38–0.49) of length of pectoral-fin anterior margin; pelvic fin surface area subequal to anal fin area; their anterior margins weakly convex, apices broadly rounded, posterior margin almost straight, free rear tips little attenuated and bluntly angular, inner margins almost straight.
First dorsal fin low, subtriangular, broadly rounded apically; anterior margin almost straight to weakly convex, extending forward as a short ridge; posterior margin initially convex, becoming straight medially and then concave posteriorly; free rear tip short, broad based, acutely pointed; inner margin slightly elevated distally; midpoint of its base closer to pectoral-fin insertions than pelvic-fin origins; its posterior and anterior margins angled more or less evenly from apex; first dorsal-fin base 0.54 (0.52–0.57) in shortest interdorsal space, 0.41 (0.42–0.46) in dorsal caudal margin; first dorsal-fin height 2.03 (1.90–2.25) times inner margin; first dorsal-fin base 3.18 (3.13–3.63) times first dorsal-fin inner margin.
Second dorsal fin relatively tall, more upright and elevated than first dorsal fin; apex narrowly rounded; much larger in area than first dorsal fin, second dorsal-fin height 1.21 (1.05–1.29) of first dorsal-fin height, base 1.15 (0.73–1.16) of first dorsal-fin base; a long, low ridge preceding main part of fin, its length variable, 0.19 (0.18–0.32) of main fin length making its origin difficult to detect; anterior margin oblique, almost straight; posterior margin upright then becoming concave toward fin base; free rear tip short, acutely pointed; inner margin straight, non-elevated distally; fin insertion slightly behind anal-fin free rear tip, well behind anal-fin insertions by about a third length of anal-fin base length; free rear tip well forward of origin of caudal fin; second dorsal-fin base length 0.69 (0.64–0.69) in length of dorsal caudal space; second dorsal-fin height 0.67 (0.58–0.70) in second dorsal-fin base length.
Anal fin low, subtriangular, broadly rounded apically, anterior and posterior margins evenly oblique; much smaller than second dorsal fin, anal-fin height 2.92 (2.87 in paratype CSIRO H 7193–01) in second dorsal-fin height, anal-fin base length 1.58 (1.42) in second dorsal-fin base length; its anterior margin concave basally and straight to convex distally, apex bluntly rounded, posterior margin almost straight, free rear tip short and acutely pointed, inner margin straight. Anal-fin base with very short preanal ridge; anal-fin origin only slightly behind origin anteriormost elevation of second dorsal fin, and well behind origin of predorsal ridge; free rear tip well forward of ventral caudal-fin origin; anal-fin base length 1.14 (1.39) in anal-caudal space; anal-fin height 0.36 (0.32) of anal-fin base length; length of anal-fin inner margin 1.39 (1.17) in anal-fin height, 3.81 (3.62) in anal-fin base length.
Caudal fin short, narrow-lobed and strongly asymmetrical, terminal lobe enlarged. Dorsal caudal margin biconvex, mesially concave before subterminal notch; no lateral undulations; length 0.29 (0.28–0.29) in precaudal length. Preventral caudal margin relatively elongate, length 3.13 (2.98–3.63) in dorsal caudal margin; basally concave, anterior margin almost straight; apex of ventral caudal lobe obtusely rounded. Postventral margin weakly concave, irregular; subterminal notch narrow; subterminal margin almost straight; terminal margin weakly biconcave, irregular; lobes formed by this margin narrowly rounded; apex of caudal fin narrowly rounded.
Vertebral counts are based on the holotype (PNM 15175) and one paratype (CSIRO H 7193–01, in parentheses): monospondylous precaudal centra 44 (45), dorsal precaudal centra 97 (101), ventral precaudal centra 94 (99), diplospondylous centra 107 (109), total centra 151 (154).
Coloration. When fresh: body almost uniformly medium brown dorsally, dusky ventrally with some whitish patches; margin of orbit blackish; jaws whitish, mouth speckled brownish and white; anterior portion and apices of dorsal fins blackish, posterior margins paler translucent dusky, free rear tip whitish; anal fin greyish brown, posterior margin and free rear tip paler, anterior margin and apex blackish; terminal lobe of caudal fin with narrow dark upper and lower margins, a pair of pale dusky blotches near its posterior margin; ventral lobe brownish basally with a broad brownish black margin; pectoral fin dorsal surface brownish, greyish brown ventrally; dorsal surface of pelvic fins brownish, slightly paler ventrally with a narrow black anterior margin. Paratypes similar to holotype with this plain coloration retained in preservative.
Size. Small shark reaching at least 652 mm TL and 2.0 kg (female); smallest adult male 580 mm TL.
Distribution. Known only from off Palawan Island (Philippines) in the western sector of the Sulu Sea basin; collected on the insular slope at about 730 m depth.
Etymology. Named in reference to the Sulu Sea, an important marine region of the southern Philippines with a rich biodiversity, which is also the type locality of this shark. The epithet ‘suluensis’ established here has been used previously in combination with Gollum in biodiversity lists (i.e. Global Biodiversity Information Facility Data Portal and Global Names Index, GBIF, 2011), presumably based on holdings of the museums and collections web site for Philippine specimens. However, prior to its use herein, the name was not available (nomen nudum) as it failed to meet requirements of Article 13 of the code International Code of Zoological Nomenclature, 1999 (i.e. lacking a definition or description, as well as a designated type specimen).
Comparisons. Gollum suluensis differs from G. attenuatus in having an overall darker and plainer coloration when fresh. The dorsal surface is less strongly contrasted, particularly around the head where the lateral demarcation of a dark dorsal surface and a whitish ventral surface are abrupt in G. attenuatus (often less obvious in preserved material). Also, the tips of dorsal fins are darker than the fin base in G. suluensis (not appreciably so in G. attenuatus), the ventral margin of the caudal fin is dusky and not strongly contrasted with the rest of the fin (rather than whitish and very strongly contrasted), and the mouth is dark (rather than pale). Also, the body of G. suluensis tends to be softer and more flexible than G. attenuatus.
These species also differ substantially in several morphometric characters: length proportions around the head of G. suluensis are typically smaller than in G. attenuatus (horizontal preorbital length 7.1–8.1% vs. 8.5–9.3% TL, prenarial length 5.9–6.4% vs. 7.4–7.8% TL, preoral length 7.9–8.5% vs. 8.7–9.3% TL); head and associated structures of G. suluensis relatively broader (head width 12.0–14.3% vs. 9.9–10.7% TL, mouth width 8.8–9.7% vs. 7.6–8.0% TL, nostril width 2.4–2.7% vs. ~2.1% TL); the spiracle of G. suluensis smaller (spiracle length 0.4–0.8% vs. ~1.0% TL); the pectoral fin is larger in G. suluensis (pectoral posterior margin 11.6–12.3% vs. 9.3–9.7% TL, pectoral base 5.3–5.9% vs. 4.6–4.8% TL); the first dorsal-fin base slightly smaller 9.3–10.0% vs. 10.3–11.1% TL); and the upper lobe of the caudal fin is relatively longer in G. suluensis (dorsal caudal margin 21.9–22.8% vs. 20.3–20.7% TL) but the lower lobe is shorter (preventral caudal margin 6.3–7.3% vs. 7.6–8.0% TL).
Morphometric differences discussed above are best demonstrated by the following non-standard ratios: preoral length/mouth width 0.82–0.96 in G. suluensis vs. 1.08–1.22 in G. attenuatus; spiracle length/eye to spiracle 0.29–0.71 vs. 0.81–0.91; preoral length/prenarial length 1.27–1.33 vs. 1.18–1.20; eye length/nostril width 1.40–1.50 vs. 1.82–1.89; head length/nostril width 8.00–8.96 vs. 10.25–10.91; prenarial length/subterminal caudal margin 1.61–2.14 vs. 2.81–2.86; direct snout length/interorbital space 1.20–1.38 vs. 1.66–1.83; dorsal caudal margin/preventral caudal margin 2.98–3.63 vs. 2.60–2.66; length of first dorsal-fin base/dorsal caudal margin 0.41–0.46 vs. 0.50–0.55; and internarial space/nostril width ~1.47 vs. 1.82–1.91.
They also differ in vertebral counts: monospondylous centra 44–45 in G. suluensis vs. 50–53 (n=5, based on 4 new specimens (NMNZ P 5724, P 7351, P 39440, and CSIRO H 6077–05) and a specimen from Compagno, 1988) in G. attenuatus, dorsal precaudal centra 97–101 vs. 105–111, ventral precaudal centra 94–99 vs. 107–113, diplospondylous centra 107–109 vs. 111–115, total centra 151–154 vs. 162–168.
G. suluensis G. attenuatus
Holotype Paratypes (n=4) Non-types (n=2) Min Max Min Max ......continued on the next page
G. suluensis G. attenuatus Holotype Paratypes (n=4) Non-types (n=2) Min Max Min Max CLO–Clasper outer length 4.9 - 4.8 - 4.3 CLB–Clasper base width 1.3 - 1.3 - - D1L–First dorsal-fin length 12.0 12.0 13.2 12.6 14.0 D1B–First dorsal-fin base 9.3 9.4 10.0 10.3 11.1 D1H–First dorsal-fin height 5.9 5.5 6.4 6.1 6.5 D 1I –First dorsal-fin inner margin 2.9 2.6 3.2 2.9 3.0 D2L–Second dorsal-fin length (main part) 13.0 12.1 13.4 14.4 16.1 D2B–Second dorsal-fin base 10.6 9.8 11.6 12.3 13.2 D2H–Second dorsal-fin height 7.2 6.7 7.3 6.9 7.4 D 2I –Second dorsal-fin inner margin 2.3 2.1 2.7 2.4 2.5 ANL–Anal-fin length 8.2 8.8 8.5 8.8 ANB–Anal-fin base 6.7 7.2 6.3 6.4 ANH –Anal-fin height 2.5 2.3 3.2 3.2 ANI–Anal-fin inner margin 1.8 2.0 2.0 2.3 CDM–Dorsal caudal margin 22.7 21.9 22.8 20.3 20.7 CPV–Preventral caudal margin 7.2 6.3 7.3 7.6 8.0 CST–Subterminal caudal margin 3.7 2.9 3.9 2.6 2.7 Remarks. Gollum attenuatus was initially known only from New Zealand seas (Garrick 1954, Compagno 1988) where it has since been collected widely using bottom longlines; north to the Wanganella Bank (32°35’S) and the Three Kings Ridge (28°10’S) (Yano, 1993a), and south to at least the Snares Islands (48°54’S) (Yano, 1993b), where the primary depth interval for more than 750 specimens was from 500–600 m (Yano, 1993b). More recently, material was collected during French exploratory surveys around New Caledonia (Séret, 1997), and later in 2003 during the NORFANZ voyage, an internationally funded survey of the Lord Howe Rise and Norfolk Ridge (Williams et al., 2006).
While making a quick comparison of material held in Paris, Séret and Last (unpublished data) noted some minor coloration differences between preserved specimens of Gollum attenuatus from New Zealand and material collected further north of New Caledonia. Garrick (1954) originally described his Triakis attenuata as being ‘generally brownish grey, but lower surface of trunk, pectorals and caudal, and distal portions of the other fins greyishwhite’, and old material from New Zealand held at the MNHN and NMNZ fit this general description (see Fig. 1 B). The more recently collected material from New Caledonia and the Norfolk Ridge have a strongly contrasted dorsal and ventral coloration with significant patches of white on the fin margins, and a prominent dark bar near the posterior margin of the caudal fin (see Fig. 1 C). Based on Séret and Last’s provisional findings, Compagno et al. (2005) treated these colour variations as separate species, referring to the New Caledonian form as Gollum sp. B. However, further inspection of available material by the senior author indicated that differences between these forms are more likely to be due to artifacts of preservation. The same material from New Zealand, when immersed in preservative, retains evidence of these distinctive contrasting pale and dark areas on the body and fins, including the caudal bar. Nonetheless, more work, particularly with the aid of molecular methods, is needed to be conclusive.
Nothing is known of the biology of G. s u l u e n s i s but it may have a similar habitat, reproductive strategy and food habit to its congener. Gollum attenuatus matures at about 700 mm TL in both sexes (Yano, 1993a) and reaches 1092 mm TL (Yano, 1993b). It usually has a litter size of two. Each ovum produces ca 50–100 ova, of which ca 30–80 are enclosed in an egg capsule. Only one embryo develops in each capsule, and the undeveloped ova are ingested and passed to an external yolk sac that produces nutrition for the developing embryo (Yano, 1993a). Gollum attenuatus lives near the bottom and feeds mainly on fishes (small sharks and teleosts), as well as small benthic invertebrates (Yano, 1993b).
description: Published as part of Last, Peter R. & Gaudiano, Joe P., 2011, Gollum suluensis sp. nov. (Carcharhiniformes: Pseudotriakidae), a new gollumshark from the southern Philippines, pp. 17-30 in Zootaxa 3002 on pages 19-28, DOI: 10.5281/zenodo.206699