Tiger Shark
Galeocerdo cuvier
Summary 2
The tiger shark, Galeocerdo cuvier, is a species of requiem shark and the only member of the genus Galeocerdo. Commonly known as sea tiger, the tiger shark is a relatively large macropredator, capable of attaining a length of over 5 m (16 ft). It is found in many tropical and temperate waters, and it is especially common around central Pacific islands. Its name derives from the dark stripes down its body which resemble a tiger's pattern, which fade...
Description 3
Common names: shark (English), tiburón (Espanol)
Galeocerdo cuvier (Peron & Lesueur in Lesueur, 1822)
Tiger shark
Head, and body stout but becoming very slender towards tail; snout very short, blunt and slightly rounded (its length 0.7-1.1 of distance between nostrils); long groove over top of mouth to under eye; spiracle a narrow slit behind large, round eye; mouth large, wide; characteristic cockscomb teeth (serrated, front edge convex, oblique tip with a deep notch on lower rear side); strong ridge on back between dorsal fins; origin of dorsal fin over posterior corner of pectoral fin; first dorsal fin not very large (height 7.5-9.3% of TL) tip pointed, rear edge concave; origin of second dorsal fin distinctly in front of anal fin origin; a low keel along each side of the narrow tail base; tail strongly asymmetric, with sharp pointed tip, large pointed lower lobe.
Adults grey with vertical bars on upper half of sides (sometimes faint or absent); young with large dark spots, some coalescing to form bars.
Size: attains > 550 cm (1 record to 740 cm).
Habitat: coastal pelagic, often in turbid areas, and estuaries, but also on reefs; retires to deeper water during the day, and feeds on shallow reefs at night.
Depth: 0-350 m.
Circumtropical; throughout our region.
National distribution 4
United States
Origin: NativeRegularity: Regularly occurring
Currently: Present
Confidence: Confident
Type of Residency: Year-round
Morphology 5
Dorsal spines (total): 0; Dorsal soft rays (total): 0; Analspines: 0; Analsoft rays: 0
Size 6
Maximum size: 7400 mm TL
Description 7
Found in both coastal and oceanic waters, including estuaries. Nocturnal feeder on mammals, tortoises, birds, sea snakes, squids, gastropods, crustaceans, and detritus. Ovoviviparous. One of the most common of the large sharks in the tropics, second only to @Carcharodon carcharias@ in recorded attacks on humans. At least 27 documented attacks are sourced to it. The 910 cm record unconfirmed. One specimen, reportedly taken off Indo-China, weighed 3,110 kg and measured 740 cm (Ref. 9987). May be caught using longlines (Ref. 5213). Valued for its meat and fins as well as its excellent hide; utilized fresh, dried-salted, smoked and frozen (Ref. 9987).
I dnature guides 8
Identification key for shorefishes of the tropical eastern Pacific
Habitat 9
Habitat Type: Marine
Ecosystem roles 10
As top predators in their ecosystem, it is possible that tiger sharks control populations of prey species, although this has not been verified. Tiger sharks also serve as a host for remoras, which are small suckerfish. Tiger sharks and remoras share a commensal relationship: remoras attach to tiger sharks near the underbelly, and use the shark for transportation and protection. Remoras also feed on materials dropped by tiger sharks. Recently, copepods, specifically sea louse, have been discovered around the eyes of tiger sharks in Australia.
Commensal/Parasitic Species:
- Remoras Echeneidae
- Sea louse Caligus oculicola
Communication and perception 11
Tiger sharks rely on electromagnetic receptors to perceive their environment and to hunt prey. Sensing organs called Ampullae of Lorenzini, located on the end of their nose, are filled with a jelly-like substance that reads electromagnetic signals. These signals are sent from the pores to the sensory nerve, and then to the brain. While hunting, tiger sharks uses this ability to detect electromagnetic signals given off by fish. Tiger sharks also use these organs to sense changes in water pressure and temperature (Plessis, 2010). Members of this species also have a lateral line on both sides of the body that runs from the gill line to the base of the tail. The lateral line reads the vibrations in the water from the movement of other animals nearby. Ampullae of Lorenzini and lateral lines also help detect electromagnetic signals from other sharks. While communally feeding on carcasses, sharks give off signals signifying dominance and thus the order in which they feed.
Communication Channels: visual ; electric
Perception Channels: tactile ; vibrations ; electric ; magnetic
Life cycle 12
Ovoviviparous (Ref. 4805, 6871) with 10-82 in a litter (Ref. 26346). Mating takes place even before gravid females have given birth (Ref. 244). Distinct pairing with embrace (Ref. 205). Gestation period: 13-16 months. Size at birth between 51 (Ref. 244) and 104 (Ref. 9997) cm TL; born at about 51-76 cm TL (Ref.58048).
Reproduction 13
Tiger sharks are polygynandrous, meaning males and females have multiple mates; they do not pair-bond at any time. Not much is known regarding the the behaviors of finding, attracting, and defending mates of tiger sharks.
Mating System: polygynandrous (promiscuous)
Male tiger sharks reach sexual maturity when they reach an average length of 292 cm, whereas females reach sexual maturity when 330 to 345 cm in length. Females mate once every three years. Breeding seasons differ in the northern and southern hemispheres. In the northern hemisphere, females delay fertilization until March or May in order to give birth between May and June of the following year. In the southern hemisphere, females delay mating until November or January in order to give birth between February and March of the following year. Tiger sharks are one of the few species that are ovoviviparous. Females give birth to 10 to 80 pups per litter after a gestation period of 16 months. Many of these pups will not survive to adulthood. Pups weigh 3 to 6 kg at birth.
Male tiger sharks have diametric testes, which are capable of synthesizing a larger amount of sperm than radial or compound testes. The females have external ovaries that appear on the epigonal organ, which is a primary lymphoid tissue in elasmobranchs.
Breeding interval: every three years
Breeding season: Northern Hemisphere: March-May to April-June of following year. Southern Hemisphere: November-December
Range number of offspring: 3 to 80.
Average number of offspring: 35-55.
Range gestation period: 13 to 16 months.
Range birth mass: 3 to 6 kg.
Range time to independence: 1 (low) minutes.
Average age at sexual or reproductive maturity (female): 8 years.
Average age at sexual or reproductive maturity (male): 7 years.
Key Reproductive Features: seasonal breeding ; sexual ; fertilization (Internal ); ovoviviparous ; delayed fertilization
Average age at sexual or reproductive maturity (male)
Sex: male: 1825 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 2555 days.
Female tiger sharks typically gives birth in a nursery, which provides protection during birth and to the young directly after birth. Tiger sharks are born independent, and mothers do not help their pups to find food, shelter or to survive. Males play no role in the lives of their offspring. Pups, however, are born with traits that help them survive without parents, including camouflage patterning, teeth to help capture prey, and speed to avoid predators.
Parental Investment: no parental involvement; pre-hatching/birth (Provisioning: Female, Protecting: Female)
Link to Access Genomic Data 14
http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=7819&lvl=0
Sources and Credits
- (c) Albert kok, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Tigershark3.jpg/460px-Tigershark3.jpg
- Adapted by matbio from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Galeocerdo_cuvier
- Adapted by matbio from a work by (c) Shorefishes of the tropical eastern Pacific online information system. www.stri.org/sftep, some rights reserved (CC BY-NC), http://eol.org/data_objects/26219481
- Adapted by matbio from a work by (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28868660
- Adapted by matbio from a work by (c) FishBase, some rights reserved (CC BY-NC), http://eol.org/data_objects/20846465
- Adapted by matbio from a work by (c) FishWise Professional, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/24181592
- Adapted by matbio from a work by (c) WoRMS for SMEBD, some rights reserved (CC BY), http://eol.org/data_objects/28495731
- Adapted by matbio from a work by (c) Discover Life and original sources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/11586134
- Adapted by matbio from a work by (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28868662
- Adapted by matbio from a work by (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18648676
- Adapted by matbio from a work by (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18648673
- Adapted by matbio from a work by (c) FishBase, some rights reserved (CC BY-NC), http://eol.org/data_objects/20846469
- Adapted by matbio from a work by (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18648671
- (c) matbio, all rights reserved
