Tiger SharkGaleocerdo cuvier
One of the most dangerous sharks for number of attacks and fatalities attributed to it, tiger sharks can grow longer than 16 feet, and weigh more than 1,400 pounds. It is curious and aggressive in contact with humans, and an indiscriminate omnivore that is known to eat most marine animals, terrestrial animals, and even manmade garbage floating at sea. Despite the size of this slow moving requiem shark, it is a highly successful hunter because of its color pattern and speed bursts.
Order - Carcharhiniformes
Family - Carcharhinidae
Genus - Galeocerdo
Species - cuvier
Tiger shark, leopard shark, maneater shark, and spotted shark are English language common names that refer to this shark. Other names include alecrin (Spanish), amarillo (Spanish), amzani (Swahili), bhoavar (Gujarati), cabron (Spanish), cação cabeça-chata (Portuguese), carcharias (Greek), cucut macan (Malay), itachizame (Japanese), jaguara (Portuguese), jarjur (Arabic), jarjur knaza (Arabic), kethulam (Telugu), ma`o patapata (Rapa), mangeur d'hommes (French), mano pa'ele (Hawaiian), ma'o tore tore (Tahitian), marracho tigre (Portuguese), naiufi (Samoan), ngutukao (Maori), pating (Tagalog), pilithatte (Kannada), pulli sravu (Malayalam), qio saga (Fijian), requin demoiselle (French), requin tigre (Creole), requin tigre commun (French), requin-demoiselle (French), requin-tigre (French), squalo tigre (Italian), te babatababa (Kiribati), tiburón tigre (Spanish), tierhaai (Afrikaans), tigerhai (German), tigre (Portuguese), tígrisháfur (Icelandic), tiikerihai (Finnish), tijgerhaai (Dutch), tintorera (Spanish), tintureira (Portuguese), wulluven sorrah (Tamil), and zarlacz tygrysi (Polish).
Importance to Humans
Although not targeted directly by the commercial fishery in the US, the tiger shark is routinely harvested for its fins and flesh. In addition, its liver, which tends to have a very high vitamin A content, is used to produce vitamin oil while its thick, tough skin makes for quality leather. Beside its significance to the commercial fishery, the tiger shark is a highly sought after big game fish.
Danger to Humans
The tiger shark is second only to the white shark in number of reported attacks on humans. Its large size and voraciousness make it a formidable predator in the ocean. Tiger sharks can be curious and aggressive towards humans in the water and must be considered with a great deal of respect.
Both commercial and recreational fishing catch rates for this species in the mid-Atlantic region have declined since the mid-1980's, indicating that fishing pressure has adversely affected the size of the population. In contrast, relative abundance and catch rates for this species noted by commercial fisheries observers, especially for juveniles, are much higher than in previous fishery-independent and fishery-dependent surveys.
The World Conservation Union (IUCN) presently lists the tiger shark as "Near Threatened" throughout its range.
The IUCN is a global union of states, governmental agencies, and non-governmental organizations in a partnership that assesses the conservation status of species.
Geographical DistributionThe tiger shark is found throughout the world's temperate and tropical waters, with the exception of the Mediterranean Sea. It is a wide-ranging species that is at home both in the open ocean as well as shallow coastal waters. Reports of individuals from as far north as Iceland and the United Kingdom have been confirmed but are probably a result of roaming sharks following the warmer Gulf Stream north across the Atlantic.
This shark has a notable tolerance for many different kinds of marine habitat but generally prefers murky waters in coastal areas. It is commonly found in river estuaries, harbors, and other inlets where runoff from the land may attract a high number of prey items. Shallow areas around large island chains and oceanic islands including lagoons, are also part of the tiger shark's natural environment. It is often seen at the surface and has been reported to depths of 350 m (1085 ft).
Tiger sharks undergo seasonal migrations. It is well known that they move into temperate waters from the tropics for the warmer months and return during the winter. These sharks also make long oceanic migrations between islands and are capable of traveling long distances in a short amount of time.
1. Dorsal surface of juveniles have blotched coloration that fuse together to form tiger-like stripes as the shark grows. (This coloration fades and the stripes become less distinct in mature adults)
2. Snout is blunt and wide
Probably the most easy to recognize of the requiem sharks, the tiger gets its name from dark black spots and vertical bars which run the length of the body. The anterior portion of the body is stout but becomes increasingly slender posterior to the abdomen. The tiger shark has a robust head with large eyes and a very blunt snout. The mouth itself is large with long labial furrows. The broad first dorsal fin originates posterior to the pectoral axil. The much smaller second dorsal fin initiates anterior to the origin of the strongly recurved anal fin. A ridge is present along the back between the dorsal fins. A low longitudinal keel is present on the caudal peduncle and the upper lobe of the caudal fin is long and thin with a subterminal notch.
Size, Age, and Growth
One of the largest sharks, the tiger shark commonly reaches a length of 325-425 cm (10-14 ft) and weighs over 385-635 kg (850-1400 lbs). Length at birth varies from 51-76 cm (1-1.5 ft). Males reach sexual maturity at 226-290 cm (7-9 ft), while females become mature at 250-325 cm (8-10 ft). The largest specimens are believed to attain a length of over 5.5 m (17 ft) and weigh over 900 kg (2000 lbs).
First described by Peron and Lessueur in Lessueur (1822), the tiger shark was given the name Squalus cuvier. Later, Muller and Henle (1837) designated Squalus arcticus (Faber, 1829) as the type species and suggested the name Galeocerdo tigrinus. Various synonyms have been used since including: Galeus cepedianus Agassiz 1838, Galeus maculatus Ranzani 1840, Carcharias fasciatus Bleeker 1852, Galeocerdo rayneri McDonald & Barron 1868, Galeocerdo obtusus Klunzinger 1871, and Carcharias hemprichii Klunzinger 1871. The genus name Galeocerdo is derived from the ancient Greek, "γαλεος" (galeos) = Aristotle's shark and "κερδω" (kerdo) = the fox.
Prepared by: Craig Knickle