Tiger Shark, Galeocerdo cuvier
The Tiger Shark, Galeocerdo cuvier, whose common Spanish name is tintorera, is a member of the Requiem Shark or Carcharhinidae Family, known collectively as tiburónes gambuso in Mexico. Globally, this fish is the only species in the genus Galeocerdo and it is found in all Mexican oceanic waters.
The Tiger Sharks have stout bodies that become very slender towards the tail. Adults are gray with vertical bars on the upper half of their sides and transition to white ventrally. Juveniles have large dark spots, some of which coalesce into stripes as the shark matures. Their anal fin is strongly recurved. Their caudal fin is long, thin, and strongly asymmetric; it has a sharp pointed tip with a subterminal notch, a large pointed lower lobe, and a longitudinal keel at the base. Their first dorsal fin is not large and has a broad base with a pointed tip and a concave rear margin; it originates behind the pectoral fin. Their second dorsal fin originates before the anal fin. There is a ridge between the dorsal fins. They have a robust head and large rounded eyes. Their snout is blunt, wide, and slightly rounded with a large wide mouth that has long labial furrows that begin on top of the mouth and end under the eyes. They are equipped with large teeth with curved cusps and finely serrated edges. Their upper and lower teeth are similar and decrease in size further back in the mouth. Their spiracles are narrow slits. They have 5 gill slits, the last two being over the pectoral fins.
The Tiger Sharks are a wide-ranging species found globally in both open oceans and in shallow coastal waters. They are found from the surface in intertidal areas to depths up to 3,000 feet. They reach a maximum length of 5.5 meters (18 feet). They have a notable tolerance for a variety of marine habitats but are normally found in murky coastal waters. They are known to make long seasonal oceanic migrations of up to 3,400 km moving to cooler waters during the summer months. They are capable of traveling long distances in short periods of time. They are solitary hunters feeding primarily at night moving inshore and closer to the surface. They are non-selective omnivores known to eat most marine animals, terrestrial animals, and even man-made garbage floating at sea. Despite their large size and slow swimming speed, they are highly successful hunters due to their camouflage coloration and their ability to quickly generate speed. They are the only species in the family that is ovoviviparous with reproduction cycles of up to two years and gestation periods of fourteen to sixteen months. Litter sizes range from ten to eighty pups that are 51 cm (20 inches) to 90 cm (35 inches) in length. The pups are very slender and swim inefficiently making them easy prey for a variety of sharks including Tiger Sharks. They are fast growing with a lifespan of up to fifty years.
In Mexican waters the Tiger Sharks are found in all waters of the Atlantic and the Pacific.
Due to its coloration, the Tiger Shark cannot be confused with any other species.
The Tiger Sharks are caught regularly as a target species, as a by-catch of tuna and swordfish fisheries, and by squid trawl fisheries. They are targeted primarily for their fins but also for their skin, liver oil, and cartilage, as well as their meat for human consumption, although not in high demand. There is evidence of decline of several populations where they have been heavily fished with both decreased quantities and catch sizes, but in general, they do not face a high risk of extinction due to their vast global range. Continued demand, especially for their fins, may result in further declines in the future. True populations and related trends are not available due to lack of accurate reporting of global catch levels. They are the third most common large coastal shark in the Gulf of Mexico and are caught primarily with gill nets. They are also a popular global target of recreational fishermen with the current world angling record standing at 596 kg (1,310 pounds). From a conservation perspective they are currently listed as Near Threatened. Limited protection regulations implemented to date have been ineffective in slowing their population decrease. The Tiger Shark is second only to the White Shark in the number of reported attacks on humans. They are large voracious predators and should be considered extremely dangerous.
Tiger Shark, Galeocerdo cuvier, Juvenile. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, April 2012. Length: 99 cm (3 feet 3 inches).