Tiger shark

Galeocerdo cuvier

Description

The tiger shark has many distinctive characteristics making it easy to distinguish from other requiem sharks. It has a broad, flat head with a snout shorter than the width of the mouth, long labial furrows, and a slender body. The caudal fin is long and pointed with reinforcing ridges and its teeth have curved cusps with serrated edges and a deep notch on the outer margin. Juvenile tigers up to 150-180 cm in length have a distinctive mottled pattern on their dorsal surface. Striped tiger-like patterns or bars appearing on adult specimens are from spots fusing together. These bars tend to become faded as the shark ages but remain apparent on the flanks and caudal region. Color can vary from bluish or greenish gray to black above and light gray to dirty yellow or white below.

Range

The tiger shark is a common large shark found worldwide. Off North America, it is usually found on the east coast from Cape Cod to Florida and in the Gulf of Mexico and on the west coast from California southward. It is commonly found off the Carolinas, Georgia and Florida and is one of the most abundant large sharks found in the Caribbean. Tiger sharks have been known to stray far outside their normal habitat range and are occasionally encountered by offshore fishermen in Canadian waters during the summer months. They are typically caught by Canadian fishermen while fishing for tuna and swordfish in or near the Gulf Stream.

Habitat

The tiger shark is often found in tropical and warm temperate waters. It inhabits both oceanic waters (up to 140 m) as well as shallow coastal waters. They seem to prefer turbid coastal areas where fresh water runoff occurs as different prey species may congregate to feed in these areas. They have not been reported inshore in Canadian waters.

Life History

Specimens between 300 and 425 cm and 380 to 640 kg are commonly taken and the largest specimens are believed to exceed 5.5 meters. Lifespan is believed to be about 27 years

Diet

The tiger shark is a non-selective feeder and a voracious predator. It has been known to consume a wide variety of marine prey and even some terrestrial animals. Common prey include crabs, shellfish, lobsters, squid, bony fish, small sharks, skates, rays, porpoises, turtles, marine birds and mammals. A large number of inorganic artifacts and garbage associated with humans have been found in the stomachs of tiger sharks as well. With such a diverse range of prey, the tiger shark is considered the most adaptable of all shark species.

Reproduction

The tiger shark is ovoviviparous; bearing 35 to 55 pups in a single litter. Gestation is believed to last just over 12 months. Pups are generally 68 to 85 cm long at birth. The males and females mature between 4 to 7 years.

Interaction with People

The tiger shark is considered to be one of the most dangerous and aggressive shark species, becoming very active when stimulated by food.

Distinguishing Characteristics

• Distinctive mottled pattern in juveniles, striped tiger-like pattern in adults
• Cockscomb-shaped curved serrated teeth with deep notches on the outer margin
• Snout shorter than the width of the mouth, large head and slender body
• Long and pointed caudal fin with reinforcing ridges