| ||Nebrius concolor Rüppell, 1837: 62, pl. 17, fig. 2. Lectotype: Naturmuseums Senckenberg, Frankfurt, SMF-3583, 85 cm TL stuffed specimen, Massaua, Red Sea.|
| ||Ginglymostoma rueppelli Bleeker, 1852: 91. Apparently an unnecessary replacement name for Nebrius concolor Rüppell, 1837, as latter is listed as a synonym. Holotype: Specimen mentioned by Bleeker is a male 1.5 m (730 lines) TL, probably from Singapore. Holotype listed as Rikjsmuseum van Natuurlijke Histoire, Leiden, RMNH 7400, by Eschmeyer (1998: CD-ROM).|
| ||Ginglymostoma muelleri Günther, 1870: 408. Apparently based on Ginglymostoma concolor Müller and Henle, 1838d: 22, pl. 6, thought by Günther to be distinct from Nebrius concolor Rüppell, 1837. Syntypes: Two stuffed specimens mentioned by Müller and Henle, in the Institut für Spezielle Zoologie und Zoologisches Museum, der Humboldt Universität, Berlin, but possibly not extant, India. No types mentioned by Eschmeyer (1998: CD-ROM).|
| ||Scymnus porosus Hemprich and Ehrenberg, 1871, in Klunzinger, : 670 (name only, in synonymy of Ginglymostoma muelleri). Also Hemprich and Ehrenberg, 1899: 8, pl. 6, fig. 3, Red Sea; possibly no type material, see Paepke and Schmidt (1988: 162).|
| ||Nebrodes macrurus Garman, 1913: 58, pl. 8, figs 7-10. Holotype: Museum of Comparative Zoology, Harvard, MCZ-820-S, 80 cm (31.5 in) TL immature male, Port Louis Harbor, Mauritius, according to Hartel and Dingerkus (1997: xxxvii-xxxviii).|
| ||Nebrodes concolor ogilbyi Whitley, 1934: 183, fig. 1. Holotype: Queensland Museum I.1216, 955 mm female, Darnley Island, Queensland, Australia. Type status confirmed by Eschmeyer (1998: CD-ROM).|
| ||Nebrius doldi Smith, 1953a: 512, fig. 30A; Smith, 1953b: 8, pls. Types: Drawing by M.M. Smith based on photographs of a 2.9 m (9.5 ft) female? specimen from south of Beira, Mozambique, apparently no type material.|
(Lesson, 1830), |
|En - Tawny nurse shark, Fr - Requin nourrice fauve, Sp - Gata nodriza atezada.|
3Alpha Code: ORZ Taxonomic Code: 1070302401|
|Scientific Name with Original Description|
|Scyllium ferrugineum Lesson, 1830, Voy. aut. monde corv. La Coquille, 2(1): 95. Holotype: Specimen with body 101.5 cm (3 ft 4 in) and tail 35.5 cm (14 in) mentioned, possibly not saved. Type locality, Port Praslin, New Ireland, and Baie d'Offack, Waigiou (Waigeu), New Guinea.|
Head in dorsal and ventral view narrow and more or less U-shaped at all stages. Snout wedge-shaped in lateral view, moderately elongated, with preoral length about 63% of mouth width. Eyes small but usually over 1% of total length, situated laterally on head and with no subocular ridges below them but with strong supraocular ridges above them; eyes with ventral edges below level of dorsal ends of gill slits.
Gill openings laterally situated on horizontal head rim and prominently visible from above and below.
Nostrils distinctly ventral on snout. Nasal barbels moderately elongated, tapered, slender, over 1% of total length, and reaching past mouth. Lower lip trilobate and divided by shallow orolabial grooves connecting mouth with lower labial furrows. Distance between lower labial furrows about 2.1 times their length.
Tooth rows 29 to 33/26 to 28, functional series 2 to 4/2 to 4. Teeth greatly compressed, with imbricate overlap pattern, and functional series separated from replacement series by narrow toothless space. Tooth crown feet broad, cusps small, three or more moderately large cusplets on each side, and greatly widened basal ledges. Teeth osteodont and with pulp cavity filled by osteodentine.
Lateral trunk denticles more or less rounded-rhomboid in adults, with four or five incomplete weak radial ridges and a very short, blunt cusp.
Pectoral fins narrow and falcate at all stages, apically angular. Pectoral-fin origins about opposite or slightly anterior to fourth gill slits. Pectoral fins plesodic and with radials reaching about 80% into fin web, radial segments 10 or 11 in longest radials. Pelvic fins angular. Dorsal fins apically angular. First dorsal-fin origin about over or slightly ahead of pelvic-fin origins. Second dorsal fin distinctly smaller than first dorsal fin. Anal fin as large or slightly larger than second dorsal fin, apically angular. Anal-fin origin varying from slightly in front of origin of second dorsal fin to about opposite its midbase, apex behind rear tip of second dorsal fin, posterior margin extends behind level of lower caudal-fin origin. Caudal fin elongate with dorsal caudal-fin margin over 25% of total length (adults); caudal fin narrow and shallow with depth 28 to 31% of dorsal caudal-fin margin; a short and weak ventral caudal-fin lobe usually present at all stages; preventral margin much shorter than postventral margin and 36 to 45% of it; terminal lobe very short and 10 to 15% of dorsal caudal-fin margin.
Total vertebral count 189 to 195, monospondylous precaudal count 55 to 57, diplospondylous count 92 to 96 and 47 to 50% of total count. Jaws narrowly arcuate.
Intestinal valve count 23 to 24.
|fieldmarks: Moderately long barbels, nasoral grooves present but no circumnarial grooves, mouth well in front of eyes, eyes and gill openings lateral, spiracles minute, precaudal tail shorter than head and body, two spineless, angular dorsal fins and an anal fin, first dorsal fin much larger than second dorsal and anal fins, first dorsal-fin base over pelvic-fin bases, pectoral fins falcate, caudal fin moderately long, over one-fourth of total length. Colour: colour brown, from tan to rufous or yellowish to dark grey-brown according to habitat, and slowly changeable by the individual.|
|Wide-ranging in the Indo-West and Central Pacific: South Africa (KwaZulu-Natal), Mozambique, Mauritius, Seychelles, Chagos Archipelago and Madagascar to Red Sea, Maldives, Persian Gulf, India, Malaysia, Indonesia, Singapore, Thailand, Viet Nam, China, Taiwan (Province of China), Japan (Ryukyu Islands, southern Honshu), Philippines (Luzon), Papua New Guinea, Australia (Western Australia, Northern Territory, and Queensland), New Caledonia, New Ireland, Samoa, Palau, Marshall Islands, and Tahiti.|
|Habitat and Biology|
|A large, tropical inshore shark of the continental and insular shelves of the Indo-Pacific,often in the intertidal in water scarcely able to cover it and from the surf line down to a few metres depth, commonly at 5 to 30 m and ranging down to at least 70 m on coral reefs. It occurs on or near the bottom in lagoons, in channels, or along the outer edges of coral and rocky reefs, in areas with seagrass and sand on reefs, sandy areas near reefs and off sandy beaches. It prefers sheltered areas in crevices and caves on reefs but often occurs in more exposed areas in depressions or crevices. Young prefer crevices in shallow lagoons but adults are more wide-ranging.|
The tawny nurse shark is primarily nocturnal, resting in the daytime in shelters but prowling slowly about around reefs at night, although some individuals may be active in the day. In Madagascar it is described as day and night-active, and in captivity they get quite active and vigorous when food is presented to them during the day. They are social, gregarious sharks when at rest and form resting aggregations of two to a half-dozen or more in shelters, and are often seen piled inertly across or on top of one another. When resting, they are extremely sluggish. This shark has a limited home range, and individuals often return to the same area every day after foraging.
Reproduction ovoviviparous (aplacental viviparous) with cannibal vivipary or uterine cannibalism in the form of oophagy. This shark has been described as an oviparous or post-oviparous shark that retains the egg-cases until they hatch and the young are born, but recent evidence indicates that this is incorrect. Pregnant females collected from Okinawa have had one or two foetuses per uterus, 297 to 595 mm (the latter near term), with the yolk sac reabsorbed and a greatly expanded stomach filled with yolky material in foetuses 338 and 595 mm long, and also had cased eggs in the uterus. Apparently this species practices oophagy on relatively large, cased nutritive eggs (unlike many lamnoids which have very small nutritive eggs), and is the first orectoloboid known to have uterine cannibalism. It is not known whether foetuses of this species eat other foetuses (adelphophagy) as with the sand tiger (Carcharias taurus). The presence of two foetuses 338 and 297mmin the same uterus, with the smaller one slender and the larger bloated with yolk, suggests that competition between siblings for the relatively big eggs is likely and could even eliminate the less successful sibling. Adelphophagy is less likely although early stages need to be examined to eliminate it. Number of young per litter uncertain; at least four young per uterus has been suggested from cased eggs, but the size and enormous girth of the near-term Okinawan foetus and the two smaller foetuses in a litter suggests that litters are smaller, possibly one or two per uterus or even one per female, and that numbers of cased eggs in the uteri cannot be used to extrapolate litter sizes in this species. In captivity adult females lay cased eggs on the bottom, but these do not develop, and could be nutritive and unfertilized. Such free eggs may have been the basis of the suggestion that this species is oviparous. The tawny nurse shark breeds in July and August off Madagascar.
Food of this shark includes corals, crabs, lobsters and other crustaceans, Octopus, squid and probably other cephalopods, sea urchins, and reef fish including surgeonfish (Acanthuridae), queenfish (Carangidae) and rabbitfish (Siganidae), and occasionally sea snakes. While foraging the tawny shark moves along the bottom and explores depressions, holes and crevices in reefs. When it detects prey it places its small mouth very close to the victim, and uses its large pharynx as a powerful suction pump to rapidly suck in reef organisms that may be out of reach of its teeth. A few large individuals dissected by the writer had quantities of small, active reef fishes in their stomachs, presumably sucked in by the sharks as the prey fishes lay inert in shelters or on the bottom at night. Individuals caught by fishermen may reverse this sucking action, and blast streams of water out of their mouths and into the faces of their captors; they are said to make a grunting sound between blasts. It is not known if spitting water is deliberate and defensive or if the sharks are actually aiming the water at the anglers. They also tend to spin when hooked on a line, making them difficult to handle and subdue.
The body form of the tawny nurse shark (littoral morphotype) is more fusiform and streamlined than other nurse sharks, with narrow-based, falcate, plesodic pectorals, pointed dorsal and anal fins with the anal-fin apex raked posterior to the free rear tip, a short ventral caudal-fin lobe, lateral eyes and gills, a narrow head, flat wedge-shaped snout, and compressed, semi-blade-like, imbricate teeth in discrete series. The tawny nurse shark superficially resembles certain other large, partly or mostly sympatric, active reef sharks including the sand tiger shark (Carcharias taurus), sicklefin lemon shark (Negaprion acutidens), and reef whitetip shark (Triaenodon obesus). Whether it is behaviourally divergent from other nurse sharks awaits a detailed comparative study of nurse shark behaviour. Its status as a game fish in Australia, unlike the nurse shark in the western Atlantic, suggests that it may be a more active swimmer when not resting on the bottom.
|Size: Maximum about 314 to 320 cm, though most individuals are smaller; size at birth has been reported as about 40 cm (Fourmanoir and Laboute, 1976) but subsequent data from a pregnant female captured off Okinawa suggest that it may reach 60 cm or more at birth (Teshima et al. 1995), while a 79 cm female from Navotas market in Manila, Philippines, examined by the writer, has a somewhat bloated stomach full of yolk, suggesting that it was newborn or a term foetus; males are mature at about 250 cm and reach at least 301 cm; adult females are 230 to at least 290 cm.|
|Interest to Fisheries|
|Common or formerly common in areas where it occurs, and caught inshore by fishermen in Pakistan, India, Thailand, and Philippines, and probably widely captured elsewhere.|
It is utilized fresh and dried-salted for human food, its liver is rendered for oil and vitamins, its fins are used in the oriental sharkfin trade, and offal is processed into fishmeal. Its thick, armour-like hide is potentially valuable for leather.Off Queensland, Australia, it has been fished as a big-game shark, and large individuals are prized as powerful fighters by sports anglers. Apart from anglers who target this fish, it is apparently primarily caught only as an untargeted bycatch of fisheries in inshore waters in nets, on line gear, and in fish traps.
This is a tough, hardy shark that readily survives in captivity and makes an excellent and handsome display animal. It is kept in aquaria in Europe, Japan (Okinawa), Singapore, and the United States. In Singapore in 1996 the writer saw several large Nebrius about 2 m long being hand-fed by a SCUBA diver in a big oceanarium tank. The sharks piled on top of their benefactor and hid him from sight while eagerly scrambling to obtain food.
Conservation Status : The conservation status of this shark is uncertain and urgently needs investigation despite its wide range. In some areas, including the Gulf of Thailand where it was commonly caught in the 1960s, it may have been depleted due to increasing fisheries activity and habitat degradation. Also, reef habitats have been extensively damaged or destroyed by dynamiting and poisoning in parts of its range, including Indonesia and Philippines, which probably have had an adverse effect on this species both directly and through decimation or elimination of its prey. Its docility and inshore habitat makes it particularly susceptible to a wide variety of fishing gear, to harassment and injuries by divers, and to reef destruction and pollution.
Tawny shark ,
Spitting shark ,
Rusty shark ,
Rusty catshark ,
Sleepy shark ,
Madame X .|
|South Africa :
Giant sleepy shark .|
Roussette ferrugineuse .|
Be kal mora .|
|Several individuals from Okinawa and Honshu, Japan and at least one from Taiwan (Province of China) have been found with their second dorsals missing or rudimentary. It is not known why this occurs in these localities, but there are some interesting possibilities that might be investigated including teratogenic effects of chemical pollutants.|
Threat to humans: This has been described as a much more docile species than its close relative, Ginglymostoma cirratum, and apparently tolerates close proximity of divers and usually allows humans to touch and play with it without biting. However, there are a few records of these sharks biting their tormentors, and clamping tightly onto them. Because of its size, strength, powerful jaws and small but sharp cutting teeth, the tawny shark should be treated with the respect due it. It is a favourite species for observation by ecotouristic divers within its enormous range, and dive sites where it is viewed are known from Thailand (Andaman Sea) and the Solomon Islands.
|Source of Information|
|Sharks of the world An annotated and illustrated catalogue of shark species known to date. Volume 2 Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). Leonard J.V. Compagno 2001.
FAO Species Catalogue for Fishery Purposes. No. 1, Vol. 2. Rome, FAO. 2001. p.269.|
Anderson & Ahmed, 1993
Bass, D'Aubrey & Kistnasamy, 1975c
Bigelow & Schroeder, 1948
Compagno, 1984, 1988
Compagno, Ebert & Smale, 1989
Fourmanoir & Laboute, 1976
Gohar & Mazhar, 1964
Jordan & Seale, 1906
Last & Stevens, 1994
Müller & Henle, 1839
Nakaya & Shirai, 1984
Taniuchi & Yanagisawa, 1987
Teshima et al., 1995, 1999
Whitley, 1934, 1940
Yoshino et al., 1981