Sealife guideSharks: guardians of the oceanMarine vertebrates

Last updated on 02/05/2026 at 10:36 PM
Sharks, like rays, belong to the class of chondrichthyans, which includes all cartilaginous fish. Within this class, sharks are part of the subclass of elasmobranchs.
Classification
Sharks are classified into eight orders, mainly according to the shape and arrangement of their different fins:
  1. the order Carcharhiniformes29 species
  2. Explore the sharks of the order Carcharhiniformes, the largest shark group, characterized by their nictitating membranes, diverse sizes and varied diets ranging from small fish to marine mammals.
    Lemon shark (Negaprion brevirostris)
    Lemon shark
    (Negaprion brevirostris)
    Pyjama shark (Poroderma africanum)
    Pyjama shark
    (Poroderma africanum)
    Sandbar shark (Carcharhinus plumbeus)
    Sandbar shark
    (Carcharhinus plumbeus)
    Scalloped hammerhead (Sphyrna lewini)
    Scalloped hammerhead
    (Sphyrna lewini)
  3. the order Heterodontiformes4 species
  4. Explore the sharks of the order Heterodontiformes, known for their distinctive blunt heads and unique teeth, which help them crush hard-shelled prey like sea urchins and mollusks.
    Crested hornshark (Heterodontus galeatus)
    Crested hornshark
    (Heterodontus galeatus)
    Horn shark (Heterodontus francisci)
    Horn shark
    (Heterodontus francisci)
    Port Jackson shark (Heterodontus portusjacksoni)
    Port Jackson shark
    (Heterodontus portusjacksoni)
    Zebra bullhead shark (Heterodontus zebra)
    Zebra bullhead shark
    (Heterodontus zebra)
  5. the order Hexanchiformes2 species
  6. Discover the sharks of the order Hexanchiformes, easily recognized by their six or seven gill slits, ancient lineage and deep-sea habitats.
    Broadnose sevengill shark (Notorynchus cepedianus)
    Broadnose sevengill shark
    (Notorynchus cepedianus)
    Frilled shark (Chlamydoselachus anguineus)
    Frilled shark
    (Chlamydoselachus anguineus)
  7. the order Lamniformes6 species
  8. Explore the sharks of the order Lamniformes, known for their large size, powerful swimming and iconic species like the great white shark and the mako shark.
    Basking Shark (Cetorhinus maximus)
    Basking Shark
    (Cetorhinus maximus)
    Great white shark (Carcharodon carcharias)
    Great white shark
    (Carcharodon carcharias)
    Longfin mako (Isurus paucus)
    Longfin mako
    (Isurus paucus)
    Short fin mako (Isurus oxyrinchus)
    Short fin mako
    (Isurus oxyrinchus)
  9. the order Orectolobiformes11 species
  10. Explore the sharks of the order Orectolobiformes, also called carpet sharks, including species like the whale shark and bamboo sharks, often found resting on the sea floor or camouflaged among reefs.
    Blind shark (Brachaelurus waddi)
    Blind shark
    (Brachaelurus waddi)
    Japanese wobbegong (Orectolobus japonicus)
    Japanese wobbegong
    (Orectolobus japonicus)
    Tasselled wobbegong (Eucrossorhinus dasypogon)
    Tasselled wobbegong
    (Eucrossorhinus dasypogon)
    Whale shark (Rhincodon typus)
    Whale shark
    (Rhincodon typus)
  11. the order Pristiophoriformes0 species
  12. Explore the sharks of the order Pristiophoriformes, also known as sawsharks, recognized by their long, toothed snouts used to detect and capture prey on the sea floor.
  13. the order Squaliformes3 species
  14. Explore the sharks of the order Squaliformes, commonly called dogfish sharks, which are generally small to medium-sized deep-sea sharks known for their spiny dorsal fins and discreet behavior.
    Greenland shark (Somniosus microcephalus)
    Greenland shark
    (Somniosus microcephalus)
    Leafscale gulper shark (Centrophorus squamosus)
    Leafscale gulper shark
    (Centrophorus squamosus)
    Spiny dogfish (Squalus acanthias)
    Spiny dogfish
    (Squalus acanthias)
  15. the order Squatiniformes2 species
  16. Explore the sharks of the order Squatiniformes, known as angel sharks, which have flattened bodies and broad pectoral fins, allowing them to lie camouflaged on the sea floor while waiting to ambush prey.
    Common angelshark (Squatina squatina)
    Common angelshark
    (Squatina squatina)
    Pacific angelshark (Squatina californica)
    Pacific angelshark
    (Squatina californica)
Description
Shark anatomy
Shark anatomy
Geographic range and habitat
Sharks are found in all the world's seas and oceans, across all latitudes and at all depths: from warm tropical waters to icy polar waters, from shallow waters along coasts and coral reefs to the deep sea !
Some shark species are pelagic, while others are benthic and live resting on the seafloor.
Diet
Most often resting during the day, sharks feed mainly at night, when they are most active in searching for prey.
Sharks are top predators at the apex of the marine ecosystem's food chain. Their diet is mainly carnivorous but highly varied: mollusks for nurse sharks, squid, octopuses, fish of all sizes, sea lions, seals and even plankton for the whale shark and the basking shark.
The whale shark feeds only on plankton !
The whale shark feeds only on plankton ! © | Dreamstime.com
To protect their eyes when attacking prey, some sharks like the great white shark can roll their eyes back, while others like the tiger shark have a very strong, semi-transparent nictitating membrane that covers their eyes like a third eyelid !
Reproduction
Typically in fish, fertilization is external after the release of male and female gametes into seawater. Sharks, however, are an exception to this rule and have internal fertilization. The male shark's pelvic fins have evolved into reproductive organs called claspers.
All sharks have internal fertilization, but the development and feeding of the embryo vary depending on the species. Some sharks are oviparous, others are ovoviviparous, the most common reproductive mode and a few are viviparous, such as the lemon shark.
The capsule containing the shark egg is called a mermaid's purse
The capsule containing the shark egg is called a mermaid's purse © | Dreamstime.com
For oviparous sharks, the eggs are enclosed in small transparent sac-like capsules. These capsules are called « mermaid's purses ».
Did you know?
  • There are currently more than 380 species of sharks worldwide !
  • The largest fish is a shark: the whale shark, measuring up to 65 feet long !
Discover sharks
Basking Shark (Cetorhinus maximus)
Basking Shark
(Cetorhinus maximus)
Blacktip reef shark (Carcharhinus melanopterus)
Blacktip reef shark
(Carcharhinus melanopterus)
Blind shark (Brachaelurus waddi)
Blind shark
(Brachaelurus waddi)
Bonnethead shark (Sphyrna tiburo)
Bonnethead shark
(Sphyrna tiburo)
Bull shark (Carcharhinus leucas)
Bull shark
(Carcharhinus leucas)
Caribbean reef shark (Carcharhinus perezi)
Caribbean reef shark
(Carcharhinus perezi)
Galapagos shark (Carcharhinus galapagensis)
Galapagos shark
(Carcharhinus galapagensis)
Grey reef shark (Carcharhinus amblyrhynchos)
Grey reef shark
(Carcharhinus amblyrhynchos)
Lemon shark (Negaprion brevirostris)
Lemon shark
(Negaprion brevirostris)
Port Jackson shark (Heterodontus portusjacksoni)
Port Jackson shark
(Heterodontus portusjacksoni)
Puffadder shyshark (Haploblepharus edwardsii)
Puffadder shyshark
(Haploblepharus edwardsii)
Scalloped hammerhead (Sphyrna lewini)
Scalloped hammerhead
(Sphyrna lewini)
Silky Shark (Carcharhinus falciformis)
Silky Shark
(Carcharhinus falciformis)
Spotted wobbegong (Orectolobus maculatus)
Spotted wobbegong
(Orectolobus maculatus)
Tawny nurse shark (Nebrius ferrugineus)
Tawny nurse shark
(Nebrius ferrugineus)
Whitetip reef shark (Triaenodon obesus)
Whitetip reef shark
(Triaenodon obesus)
Latest news on sharks

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Thursday, April 23rd 2026
Where to see groupers in the Mediterranean ?
Discover where to see groupers in the Mediterranean: the best diving spots and protected marine areas to observe this iconic fish in its natural habitat.
The broadnose sevengill shark
Monday, April 20th 2026
The broadnose sevengill shark
Discover the broadnose sevengill shark (Notorynchus cepedianus), a large primitive coastal shark with seven gill slits living in temperate and subtropical waters around the world.
The blueface angelfish
Monday, March 2nd 2026
The blueface angelfish
The blueface angelfish is a very colorful fish of the tropical coral reefs of the Indo-Pacific, recognizable by its bright blue head and its bluish body finely reticulated with yellow.
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Langouste brésilienne (Panulirus guttatus)
Langouste brésilienne
(Panulirus guttatus)