The shark kingdom is a vast network of different species that are all unique in their own way. All in all, there are 440 different shark species out there, classified into eight different orders. Some of them are very big while others are actually quite little. There are also others that are quite aggressive while others are quite docile. It may even come to a surprise to some, but the biggest shark species out there are actually the most passive!
The Eight Groups Of Sharks: The First Four
When it comes to identifying the type of sharks that you may read about or come across, there are eight major orders out there that are based on time period and physical characteristics. They are the squantiniformes, pristiophoriformes, squaliformes, hexanchiformes, carcharhiniformes, lamniformes, orectolobiformes, and heterodontiformes.
The squantiniformes group has a flattened, ray-like body with no anal fin. The angel shark is an example, which is one of the more unusual shark species out there. Many people will mistake this shark for another sea creature! These sharks like to hang out at the bottom of the ocean, feasting mostly on clams and mollusks.
The pristiophoriformes group has no anal fin as well, but what makes it stand out is its ventral mouth, elongated snout, and unray-like body. These sharks emerged during the Jurassic period. An example from this shark group would be the sawshark.
The squaliformes group are similar to the pristiophoriformes group except that its snout is short and not saw-like. The type of sharks that are part of this group include the bramble shark, the dogfish, the roughshark, and rrickly shark.
Next is the hexanchiformes group. These sharks have an anal fin, unlike the three groups mentioned before. They also possess 6-7 gill slits and one dorsal fin. They emerged during the Permian period. The type of sharks found in this group include the cow and frilled shark.
The Eight Groups Of Sharks: The Last Four
The carcharhiniformes, lamniformes, orectolobiformes, and heterodontiformes groups all have an anal fin present as well. They also have 5 gill slits and two dorsal fins. What makes the heterodontiformes group stand out from the other three mentioned is its dorsal fin spine. The type of sharks found in this group include the bullhead shark (or horn shark).
The other three have no fin spines. However, the orectolobiformes group differentiates from the carcharhiniformes and lamniformes group due to the placement of its mouth. The mouth is located well in front of the eyes. The zebra shark, whale shark, and nurse shark are examples within the orectolobiformes group.
Both the carcharhiniformes and the lamniformes groups have their mouth located behind their eyes. What makes these groups unique from one another is their eyelids and intestinal valves. The carcharhiniformes group (which contains many common shark species such as the blue shark, tiger shark, and bull shark), has nictitating eyelids and a spiral/scroll intestinal valve. On the other hand, the lamniformes group has no nictitating eyelids, and possesses a ring intestinal valve. The type of sharks in this group include the goblin shark, basking shark, and megamouth shark.
Visit SharkSider For More Information On All Of These Wonderful Shark Species
Hopefully, you have a better understanding of the type of sharks you will find throughout the world. Just like many other species out there, the shark groups differentiate from one another due to physical characteristics. This makes it easier to classify them. On SharkSider, our team of shark lovers has extensive information on all of these shark species. Visit us today and become the shark expert amongst your friends!