Distributed throughout the world's seas and oceans, there are more than 350 species of sharks, although it is nothing comparable to the more than 1,000 fossil species that we know of. Prehistoric sharks appeared on planet Earth 400 million years ago, since then many species have disappeared and others have survived the great changes that the planet has undergone. Sharks as we know them today appeared 100 million years ago.
The variety of existing shapes and sizes means that sharks have been classified into various groups and within these groups we find dozens of species. We invite you to learn, in this article on our site, how many types of sharks there are, their characteristics and several examples.
Squatiniformes
Sharks of the order Squatiniformes are commonly known as "angel sharks". This group is characterized by not having an anal fin, having the flattened body and the well-developed pectoral finsThey look very similar to a stingray, but they are not.
The Spiny Angelshark (Squatina aculeata) inhabits the eastern part of the Atlantic Ocean, from Morocco and the western Saharan coast to Namibia, passing through Mauritania, Senegal, Guinea, Nigeria and Gabon to the south of Angola. They are also found in the Mediterranean. Despite being the largest shark in its group (almost two meters long), the species is critically endangered due to intensive fishing. They are viviparous placental animals.
In the northwest and western central Pacific we find another species of angel shark, the ringed shark (Squatina Tergocellatoides). Very little is known about this species as there are few cataloged specimens. Some data indicates that they live on the seabed at depths of between 100 and 300 meters, since they are often caught accidentally in trawling.
Other Squatiniformes shark species are:
- Eastern Angel Shark (Squatina albipunctata)
- Argentine Angel Shark (Squatina argentina)
- Chilean angel shark (Squatina armata)
- Australian Angel Shark (Squatina australis)
- Pacific Angel Shark (Squatina californica)
- Atlantic angel shark (Squatina dumeril)
- Taiwan angel shark (Squatina formosa)
- Japanese angelshark (Squatina japonica)
In the image we can see a specimen of Japanese Angelshark:
Pristiophoriformes
The order of the Pristiophoriformes is made up of the sawsharks The snout of these sharks is elongated with serrated edges, hence their name. Like the previous group of sharks, the pristiophoriformes do not have an anal fin They look for their prey on the seabed, for which they have two appendages long near the mouth used to detect prey.
In the Indian Ocean, south of Australia and Tasmania, we found the long-nosed sawshark (Pristiophorus cirratus). They live in sandy areas, at depths that vary between 40 and 300 meters, where they easily find their prey. They are ovoviviparous animals.
Deeper and in the Caribbean Sea, we found the Bahamian sawshark (Pristiophorus schroederi). This animal, physically very similar to the previous one and to the rest of the sawsharks, lives between 400 and 1,000 meters deep.
In total there are only six described species of sawshark, the other four are:
- Sixgill sawshark (Pliotrema warreni)
- Japanese sawshark (Pristiophorus japonicus)
- Southern sawshark (Pristiophorus nudipinnis)
- Western sawshark (Pristiophorus delicatus)
In the image we show you a japanese sawshark:
Squaliformes
The order Squaliformes is made up of more than 100 species of shark. The animals of this group are characterized by having five pairs of gill openings and spiracles, which are holes related to the respiratory system. No nictitating membrane or third eyelid, No anal fin
In almost all the seas and oceans of the world we can find bramble sharks (Echinorhinus brucus), also known as nailfish. Almost nothing is known about the biology of this species. They seem to inhabit depths between 400 and 900 meters, although they have also been found much closer to the surface. They are ovoviviparous animals, relatively slow and with a maximum size of 3 meters in length.
Another better-known squaliform shark is the Spiny Sea Pig or Spiny Dogfish (Oxynotus bruniensis). It lives in the waters of southern Australia and New Zealand, in the Southwest Pacific and eastern India. It has been seen in a very wide depth range, between 45 and 1,067 meters. They are small animals, reaching a maximum size of 76 centimeters. They are placental ovoviviparous with oophagia.
Other known species of squaliformes sharks are:
- Smooth dogfish (Mollisquama parini)
- Small-eyed Pygmy Dogfish (Squaliolus aliae)
- Screech-Toothed Tollo (Miroscyllium sheikoi)
- Black Quelvacho (Aculeola nigra)
- White-tailed hag (Scymnodalatis albicauda)
- Black Tollo (Centroscyllium fabricii)
- Plunket shark (Centroscymnus plunketi)
- Japanese Witch (Zameus ichiharai)
In the photograph it is possible to observe a specimen of Pygmy Small-eyed Dogfish:
Carcharhiniformes
This group includes around 200 species of sharks, including some well-known ones such as the hammerhead shark (Sphyrna lewini). Animals belonging to this order and to the following order have anal fin This group is also characterized by having a flat snout , a very wide mouth that exceeds the limit of the eyes, whose lower eyelid acts as a nictitating membrane and in their digestive system they have a coiled intestinal valve
The tiger shark (Galeocerdo cuvier) is one of the best-known sharks, and according to shark attack statistics, it, together with the bull shark and the white shark, are the ones that register the most attacks. The tiger shark lives in tropical and temperate oceans and seas around the world. It is found on the continental shelf and reefs. They are viviparous with oophagia.
The dogfish (Galeorhinus galeus) inhabits the waters that bathe western Europe, western Africa, South America, the west coast of the United States and the southern part of Australia. It prefers shallow areas. They are aplacental viviparous with litters of between 20 and 35 pups. They are relatively small sharks, between 120 and 135 centimeters.
Other species of carcharhiniformes are:
- Gray shark (Carcharhinus amblyrhynchos)
- Bearded shark (Leptocharias smithii)
- Harlequin-tailed Dogfish (Ctenacis fehlmanni)
- Tollo toothed plane (Scylliogaleus quecketti)
- Harpoon-toothed Galeus (Chaenogaleus macrostoma)
- Half-moon Galeus (Hemigaleus microstoma)
- Elongated Galeus (Hemipristis elongata)
- Whitetip shark (Carcharhinus albimarginatus)
- Caribbean reef shark (Carcharhinus perezi)
- Borneo Shark (Carcharhinus borneensis)
- Nervous shark (Carcharhinus cautus)
The specimen in the image is a hammerhead shark:
Lamniformes
Lamniform sharks have two dorsal fins and one anal finThey do not have nictitating eyelids, they have five gill slits and spiracles The intestinal valve is ring-shaped. Most have elongated snouts and their mouths open behind their eyes.
The strange Goblin shark (Mitsukurina owstoni) has a global but patchy distribution, they are not evenly distributed throughout the oceans. It is possible that this species is found in more places, but the data comes from accidental catches in fishing nets. They live between 0 and 1,300 meters deep, they can exceed 6 meters in length. The type of reproduction and its biology are not known.
The basking shark (Cetorhinus maximus) is not a large predator like other sharks in this group, it is a very cold water species. large, which feeds by filtration, is migratory and is widely distributed throughout the seas and oceans of the planet. Populations of this animal found in the North Pacific and Northwest Atlantic are in danger of extinction.
Other species of Lamniformes sharks:
- Bull Shark (Carcharias Taurus)
- Bambaco bull (Carcharias tricuspidatus)
- Crocodile shark (Pseudochararias kamoharai)
- Widemouth shark (Megachasma pelagios)
- Pelagic Fox (Alopias pelagicus)
- Eye-eyed fox (Alopias superciliosus)
- Great White Shark (Carcharodon carcharias)
- Mako shark (Isurus oxyrinchus)
In the image you can see an image of the basking shark:
Orectolobiformes
Orectolobiform sharks live in tropical or warm waters. They are characterized by having an anal fin, two dorsal fins without spines, the small mouth in relation to the body, with nostrils(similar to nostrils) connected to the mouth, short snout , just in front of the eyes. There are about thirty-three species of orectolobiform sharks.
The whale shark (Rhincodon typus) lives in all tropical, subtropical and warm seas, including the Mediterranean. They are found from the surface to almost 2,000 meters deep. They can measure up to 20 meters, weighing more than 42 tons. Throughout its life, a whale shark will feed on different prey, based on its own growth. As it grows, the prey should also be larger.
Along the southern coast of Australia, at shallow depths (less than 200 meters), we found the carpet shark (Orectolobus haley). It usually lives around coral reefs or rocky areas, where it can easily camouflage itself. They are nocturnal animals, they only come out of their den at dusk. It is a viviparous species with oophagia.
Other orectolobiform shark species:
- False bearded catshark (Cirrhoscyllium expolitum)
- Rusty carpet shark (Parascyllium ferrugineum)
- Arabian Long-tailed Dogfish (Chiloscyllium arabicum)
- Grey Long-tailed Dogfish (Chiloscyllium griseum)
- Blind Shark (Brachaelurus waddi)
- Tawny Nurse Shark (Nebrius ferrugineus)
- Zebra shark (Stegostoma fasciatum)
The photograph shows a specimen of carpet shark:
Heterodontiformes
Heterodontiform sharks are small animals, they have a spine on their dorsal fin, anal fin. Above the eyes they have a crest and they do not have a nictitating membrane. They have five gill slits, three of them above the pectoral fins. They have two different types of teeth , the front ones are sharp and conical, while the rear ones are flat and wide, which they use to grind food. They are oviparous sharks.
The horn shark (Heterodontus francisci) is one of the 9 extant species of this order of sharks. They inhabit mainly the southern coast of California, although the species extends to Mexico. They can be found at depths of more than 150 meters, but they are usually between 2 and 11 meters deep.
South Australia and Tanzania are home to the Port Jackson shark (Heterodontus portusjacksoni). Like the rest of heterodontiformes sharks, it lives in surface waters, being able to be found up to 275 meters deep. It is also nocturnal, during the day it is hidden in the reefs or rocky areas. They measure about 165 centimeters in length.
The rest of the heterodontiform shark species are:
- Great Horned Shark (Heterodontus galeatus)
- Japanese Horned Shark (Heterodontus japonicus)
- Mexican Horned Shark (Heterodontus mexicanus)
- Oman Great Horned Shark (Heterodontus omanensis)
- Galapagos Great Horned Shark (Heterodontus quoyi)
- African Horned Shark (Heterodontus ramalheira)
- Zebra Great Horned Shark (Heterodontus zebra)
The shark in the image is a specimen of horn shark:
Hexanchiformes
We end this article on types of sharks with the hexanchiformes. This order of sharks includes the most primitive living species, which is only six species. They are characterized by having a single dorsal fin with a spine, six to seven gill openings and they have no nictitating membrane in their eyes.
The eel or chlamys shark (Chlamydoselachus anguineus) inhabits the Atlantic and Pacific oceans in a very heterogeneous way. They live at a maximum depth of 1,500 meters and a minimum of 50 meters, although they are generally found between 500 and 1,000 meters. It is a viviparous species and it is believed that gestation can last between 1 and 2 years.
The big-eyed cowshark (Hexanchus nakamurai) is widely distributed throughout warm and temperate seas and oceans but, as in In the former case, the distribution is very heterogeneous. It is a deep water species, between 90 and 620 meters. They usually reach 180 centimeters in length. They are ovoviviparous and lay between 13 and 26 offspring.
The rest of the hexanchiformes sharks are:
- South African Eel Shark (Chlamydoselachus africana)
- Sevengill shark (Heptranchias perlo)
- Grey bootleg shark (Hexanchus griseus)
- Short-snouted cow shark or spotted shark (Notorynchus cepedianus)
The photograph shows a specimen of eel shark or chlamys shark:
