click for previous page Hemiscylliidae 1249 HEMISCYLLIIDAE Longtail carpetsharks by L.J.V. Compagno and V.H. Niem iagnostic characters: Small sharks. Trunk cylindrical or moderately depressed, precaudal tail Dcylindrical and somewhat longer than head and trunk, lateral ridges on sides of trunk and tail present or absent. Head not expanded laterally, cylindrical or moderately depressed; 5 small gill slits present, the last 3 over the pectoral-fin base, their upper ends not expanded onto upper surface of head; no gill sieves or rakers on internal gill slits; spiracles very large and located behind and below eyes; nostrils with barbels, nasoral grooves, and circumnarial grooves, close in front of mouth; eyes above and medial to sides of head, without nictitating eyelids; snout short to moderately long, slightly depressed, parabolic to broadly rounded, not greatly flattened and blade-like and without lateral teeth or barbels; mouth small, nearly transverse, and well in front of eyes, without a symphyseal groove on chin; labial furrows present on both jaws and relatively large, with upper furrows extending in front of mouth; teeth small, not blade-like, with a single cusp on upper and lower teeth and with cusplets small or absent; teeth similar in both jaws, not differentiated into medials, anteriors, intermediates, laterals, or posteriors. Two dorsal fins without spines, the first moderate sized, subangular, much shorter than the caudal fin, and with its origin over or behind the pelvic-fin bases; second dorsal fin about as large as the first and of similar shape; anal fin moderately large, very low, broad and rounded, with its origin well behind the second dorsal-fin base and its base separated by a notch from the caudal fin; caudal fin strongly asymmetrical, much less than 1/2 of total length, without a rippled dorsal margin or lower lobe but with a strong subterminal notch; vertebral axis of caudal fin hardly raised above body axis. Caudal peduncle cylindrical, without precaudal pits or keels. Intestinal valve of ring type. Colour: back yellowish, brownish or grey-brown, lighter below, with dark or light spots or dark saddles, sometimes absent in adults. spiracles large caudal fin strongly asymmetrical length of head and body precaudal tail Habitat, biology,and fisheries: Longtail carpetsharks are a small group of inshore tropical sharks of the Indian Ocean and western Pacific, being confined to continental waters and continental islands. They are slow-swimming bottom-dwellers, often intestinal valve of ring type clambering with their muscular paired fins on coral and rocky reefs. At least some of the species are oviparous. They feed on invertebrates and small fishes and are harmless to people. Hemiscyllium species are little utilized for fisheries, but Chiloscyllium species are commonly caught in small-scale artisanal fisheries and by bottom trawlers in the western and eastern Pacific and eastern central Indian Ocean. Similar families occurring in the area Brachaeluridae: nasal barbels longer; symphyseal groove present on chin; precaudal tail not greatly elongated, shorter than head and trunk. nasal barbels longer Brachaeluridae 1250 Sharks Ginglymostomatidae: precaudal tail not greatly elongated, shorter than head and trunk; no circumnarial grooves around nostrils; head more depressed and flattened; spiracles minute; labial furrows not connected across chin by a dermal flap (present in Hemiscylliidae); anal fin higher, more angular, and separated from the lower caudal-fin origin by a space; origin of anal fin under second dorsal-fin base. Ginglymostomatidae Stegostomatidae: precaudal tail not greatly no circumnarial barbels groove elongated, shorter than head and trunk; no circumnarial nasoral circumnarial grooves around nostrils, labial groove groove furrows not connected across chin by a dermal flap; first dorsal-fin origin far anterior to pelvic-fin bases, its insertion over or slightly anterior to pelvic-fin insertions (far posterior to pelvic-fin insertions in Hemiscylliidae), second dorsal fin much smaller than first dorsal fin; pelvic fins labial furrows much smaller than pectoral fins; anal-fin origin not connected labial furrows under second dorsal-fin base; caudal fin about as connected by long as rest of shark. dermal flap Ginglymostomatidae Hemiscylliidae (ventral view of head) Stegostomatidae Key to the species of Hemiscylliidae occurring in the area 1a. Nostrils subterminal on snout (Fig. 1a); eyes and supraorbital ridges hardly elevated; preoral snout long, mouth closer to eyes than snout tip; no black hood on head or large dark spot or spots on sides of body above pectoral fins (Fig. 1b) ........(Chiloscyllium) → 2 1b. Nostrils terminal on snout (Fig. 2a); eyes and supraorbital ridges prominently elevated; preoral snout short, mouth closer to snout tip than eyes; a large spot or spots on sides of body above pectoral fins, or a black hood on head (Fig. 2b) .........(Hemiscyllium) → 6 nostrils subterminal on snout b) lateral view a) ventral view of head Fig. 1 Chiloscyllium nostrils terminal on snout b) lateral view a) ventral view of head Fig. 2 Hemiscyllium Hemiscylliidae 1251 2a. Body and tail very slender; length of anal fin from origin to free tip subequal to length of hypural caudal-fin lobe from lower caudal-fin origin to subterminal notch (Fig. 3) .. .........................................Chiloscylliumindicum 2b. Body and tail moderately slender to relatively stout; length of anal fin considerably shorter than hypural caudal-fin lobe (Figs 4 and 5) ........................→ 3 3a. Body with lateral dermal ridges; young and adults with transverse dark bands and numerous white spots (Fig. 4) ........................Chiloscyllium plagiosum 3b. Body without lateral dermal ridges; adults usually without colour pattern, dark transverse bands in young only ........................................→ 4 Fig. 3 Chiloscyllium indicum Fig. 4 Chiloscyllium plagiosum 4a. Dorsal fins larger than pelvic fins, with projecting free rear tips (Fig. 5) .......Chiloscyllium punctatum 4b. Dorsal fins smaller than pelvic fins, without projecting free rear tips ....................→ 5 Fig. 5 Chiloscyllium punctatum 5a. First to second dorsal-fin distance usually more than 9.3% of total length; first dorsal-fin height more than 6.6% of total length; second dorsal-fin height usually more than 5.8% of total length; dark bands of juveniles not outlined in black (Fig. 6) .....Chiloscylliumgriseum 5b. First to second dorsal-fin distance less than 9.3% of total length; first dorsal-fin height less than 6.6% of total length; second dorsal-fin height usually less than 5.8% of total length; dark bands of juveniles outlined in black (Fig. 7) ............Chiloscylliumhasselti juvenile juvenile Fig. 6 Chiloscyllium griseum Fig. 7 Chiloscyllium hasselti 6a. Head and snout with an abrupt black hood; body with conspicu- ous large white spots (Fig. 8) .. .............Hemiscylliumstrahani 6b. Head and snout light, without a black hood but with conspicuous black spots above pectoral fins; body with light spots inconspicu- ous or absent ...............→ 7 Fig. 8 Hemiscyllium strahani 1252 Sharks 7a. Black spot behind gills small, not in the form of a conspicuous ocellus (Fig. 9) .... .........................................Hemiscylliumfreycineti 7b. Black spot behind gills large, in the form of a conspicuous ocellus, ringed with white (Figs 10 to 12) ...........................................→ 8 8a. Body covered with numerous, densely clustered dark small and large spots that form a reticular network of light ground colour between them; dark crossbands strong on ventral surface of tail (Fig. 10) ...........................Hemiscylliumtrispeculare 8b. Body with sparse, large spots that do not form a reticular network of light ground colour between them; dark crossbands not reaching ventral surface of tail ...............→ 9 Fig. 9 Hemiscyllium freycineti Fig. 10 Hemiscyllium trispeculare 9a. Lateral ocellus not surrounded by large spots; spots present on head in front and below eyes (Fig. 11) ................................Hemiscylliumocellatum 9b. Lateral ocellus surrounded by large black spots; spots absent from head in front and below eyes (Fig. 12) .............................Hemiscylliumhallstromi Fig. 11 Hemiscyllium ocellatum Fig. 12 Hemiscyllium hallstromi List of species occurring in the area The symbol . is given when species accounts are included. Chiloscyllium griseum Müller and Henle, 1839 . Chiloscyllium hasselti Bleeker, 1852 . Chiloscyllium indicum (Gmelin, 1789) . Chiloscyllium plagiosum (Bennett, 1830) . Chiloscyllium punctatum Müller and Henle, 1838 . Hemiscyllium freycineti (Quoy and Gaimard, 1824) . Hemiscyllium hallstromi Whitley, 1967 . Hemiscyllium ocellatum (Bonnaterre, 1788) . Hemiscyllium strahani Whitley, 1967 . Hemiscyllium trispeculare Richardson, 1845 Reference Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1. Hexanchiformes to Lamniformes. FAO Fish. Synop., (125)Vol.4.Pt.1:249 p. Dingerkus, G. and T.C. DeFino. 1983. A revision of the orectolobiform shark family Hemiscylliidae (Chondrichthyes, Selachii). Bull. Am. Mus. Nat. Hist., 176(1):1-93. Regan, C.T. 1908. A revision of the sharks of the family Orectolobidae. Proc. Zool. Soc. Lond., (1908):347-364. Hemiscylliidae 1253 Chiloscyllium griseum Müller and Henle, 1839 Frequent synonyms / misidentifications: None / Chiloscyllium hasselti Bleeker, 1852; C.