River sharks - Fact or rumor?

Of the more than 400 shark species that inhabit the waters of the world, scientists have identified five shark species that specialize in freshwater areas in rivers and lakes.

So far, studies on river shark species in the world are very limited. The scientific community determined that most river sharks belong to the five shark species Glyphis. In addition, the possibility of many other sharks living in freshwater has not been discovered by researchers.

River sharks live in freshwater areas in India, Southeast Asia and many parts of Australia. However, it is rare for people to see them with their own eyes.

Although the shark family belongs to the river, the shark seems harmless to humans. In addition, it is the fishing, environmental pollution and rapid development of humans that are seriously threatening the lives of five species of shark Glyphis.

Usually, river sharks have a short body shape, wide mouth and small eyes. They can grow up to 3m long. In addition, the body of river sharks often develop larger fins and look more like fish than sharks.

Shear tooth shark

Good-toothed shark or Glyphis glyphis is one of the most likely species to live on fast-growing mangrove and mangrove rivers in northern Australia and New Guinea.

They develop large fins on the back. Teeth grow deep under the jaw, are quite small and look like a stick so they are called "Shear teeth shark".

According to scientists, the shark teeth often move when the tide changes to save energy for the body. Their daily food is fish and crustaceans. Like many sharks, they also give birth instead of laying eggs.

The International Association for Conservation of Nature (IUCN) has listed shark teeth on the list of endangered animals. Currently, there are only about 2,500 teeth and sharks in the world are threatened by the loss of human habitat and indiscriminate fishing.

Relatives of the toothed shark include the northern river shark, also known as the New Guinea river shark (scientific name: Glyphis garricki) and the Irrawaddy river shark (scientific name: Glyphis siamensis) - discovered in a study tour of the Irrawaddy River in Myanmar in the 19th century.

"Ghost" shark

Borneo river shark ( Glyphis fowlerae ) is one of the most famous river sharks discovered in the 19th century.

According to IUCN shark researcher Leonard Compagno, scientific literature on the distribution of habitat and biological characteristics of river sharks around the world is very limited. They are like "ghosts" rarely appearing and scattered. Therefore, the discovery of the presence of river sharks is considered a strange thing.

One of the most endangered and endangered river sharks is the Ganges shark ( Glyphis gangeticus) , which specializes in freshwater in eastern and northeastern India.

Cow sharks

Ganges sharks are often mistaken for being similar in shape and structure to bull sharks (Carcharhinus leucas). They are called with many names such as river sharks, Zambezi sharks or Nicaragua sharks.

Contrary to the danger of bull sharks, Ganges sharks appear quite few and pose no danger to humans.

Bull sharks often live in shallow and warm waters along the coast and river areas around the world. They often swim very far and are known for their fierce predators and opportunities.

Occasionally, humans can catch images of sharks crawling away from the mainland of Indiana and the Ohio River. They are ranked first in the list of human attacks in the area near the coast.

It is worth mentioning that cow sharks evolve their ability to withstand life in freshwater by developing skills to limit the elimination of salt in the blood through the rectum. The gills and kidneys also help cow sharks control the amount of salt absorbed and excrete.

Usually bull sharks hunt alone but in some cases they go in pairs to hunt more food. They mark their own territory and are ready to attack unauthorized intruders.