Sharks (Selachimorpha): the most impressive elasmobranchs

Welcome to Shark Cartilage! The global network of sharks. Discover the types of sharks that exist, the notable species, the areas where they live, and the behavior of each one.

We invite you to dive into the world of sharks, where you will find the most surprising sharks, with simple and educational explanations about their age and longevity, the size they reach in adulthood, and information about their reproduction.

What categories of sharks exist?

The most fascinating and mighty sharks in the world

Sharks are cartilaginous fish present in the oceans around the world. They belong to the class Chondrichthyes and the subgroup Elasmobranchii, and the ones listed below are the most exceptional:

Classification of sharks

As mentioned, a shark is a cartilaginous fish belonging to the class Chondrichthyes and the subgroup Elasmobranchii, and these have characteristics different from other marine animals and fish. The classification of sharks is based on their taxonomy, which organizes these animals into different hierarchical levels:

  1. Kingdom Animalia: which includes all animals.
  2. Phylum Chordata: within the kingdom Animalia, sharks are in the phylum Chordata, which includes animals with a dorsal nerve cord.
  3. Class Chondrichthyes: this class groups cartilaginous fish, which have a skeleton composed mainly of cartilage instead of bone.
  4. Subclass Elasmobranchii: the subclass Elasmobranchii includes sharks and rays, possessing gills in the form of lamellae and skin covered with dermal denticles.
  5. Superorder Selachimorpha or Selachii: this superorder groups all sharks, differentiating them from rays and other elasmobranchs.
  6. Sharks are divided into various orders, some of the most well-known are:
    • 6.1 Carcharhiniformes: includes reef sharks, tiger sharks, and hammerhead sharks.
    • 6.2 Lamniformes: includes great white sharks, basking sharks, and mako sharks.
    • 6.3 Squaliformes: includes spiny sharks like the Greenland shark.
    • 6.4 Orectolobiformes: includes whale sharks and nurse sharks.
    • 6.5 Hexanchiformes: includes six and seven-gill sharks.
    • 6.6 Heterodontiformes: includes bullhead sharks.
  7. Families, genera, and species:
    • Within each order (above in the menu you have the option "order"), sharks are grouped into families, then into genera, and finally into species. For example, the great white shark belongs to the order Lamniformes, family Lamnidae, genus Carcharodon, species Carcharodon carcharias.

This taxonomic classification can vary and be subject to revisions as new studies are conducted and more information about the biology and genetics of sharks is obtained since, as you will find on, some species have been little studied.

General Characteristics of Sharks

Characteristics of Sharks

With their diversity and adaptability, each shark species has unique characteristics that make their adaptation to the environment incredible, distinguishing them from other marine animals. Here are the characteristics of these fascinating cartilaginous animals, often called sharks, that make them different:

  • Class: Chondrichthyes
  • Subgroup: Elasmobranchii.
  • Body structure: with a skeleton composed of cartilage instead of bone.
  • Respiration: through gills.
  • Skin: covered with placoid scales, also known as dermal denticles, which are similar to small teeth.
  • Reproduction: there are different types of shark reproduction, which can be oviparous, ovoviviparous, or viviparous, depending on the shark species mentioned.
  • Feeding: they are carnivorous, although there are also some filter-feeding species like the whale shark (Rhincodon typus), which instead of hunting, feeds by filtering water to capture food, mainly plankton, in a manner similar to whales.

Additionally, you will learn about endangered shark species and the conservation measures being implemented.

Our goal is to promote the conservation of shark species by spreading knowledge about these beautiful aquatic animals worldwide. We will show you the incredible beauty of the shark (Selachimorpha) so you can discover for yourself how valuable it is to the global ecosystem.

If you want to learn more about Shark Cartilage, we invite you to learn about our organization and its conservation mission. We work in collaboration with various stakeholders to preserve the biological and cultural diversity of these magnificent animals.

Where do sharks live?

Sharks inhabit a wide variety of aquatic habitats around the world. From deep oceans to shallow rivers, there are shark species in warm tropical waters and cold Arctic oceans. Their presence in nature is very broad. You can see more details about each type of shark, learn about the different freshwater sharks, the marine sharks, and of course, don't forget to learn about the deep-water sharks.

Geographic map of shark habitats and global distribution

These magnificent predators can be found in a diversity of marine environments. Many shark species prefer shallow coastal waters, where they can find an abundance of prey, while others venture into the ocean depths in search of food. Some sharks, like the great white shark, are known for their epic migrations over vast distances, while others, like the bull shark, prefer to inhabit estuaries and calmer waters. Their presence is widespread as they have been able to adapt to many types of aquatic habitats, becoming the top predators in the marine world.

Is the shark a fish?

The shark is a fish because it belongs to the group of cartilaginous fishes, also known as selachians. These fish have a skeleton made of cartilage instead of bone, distinguishing them from bony fish, but with these differences, the shark is still a fish, sharing characteristics such as a dorsal fin, pectoral fins, and a horizontal tail. However, sharks also have unique features that make them different from other fish, such as sharp teeth and the ability to produce electricity through their electrogenic cells. This is something most marine and river fish cannot do, using it to detect their prey through the ampullae of Lorenzini to feed.