Extinction of gharial

April 7, 2023, 5:02 p.m.

Gharial (Gavialis gangeticus) are pretty unique crocodilians, having diverged from others more than 40 million years ago.

The Gharial is a critically endangered and unique crocodilian species of extraordinary conservation value. Indeed, it is the rarest large animal on the Indian subcontinent.

The gharial is one of only two species in the Gavialidae family. It has a characteristic elongated, narrow snout, similar only to the tomistoma (previously called the false gharial). Many sharp, interlocking teeth line the gharial's elongated jaws.

Sadly, these unique crocodiles face a multitude of threats to their existence. The damming of rivers across their range is altering their habitat significantly and, as gharials cannot walk on land as well as other crocodilians, they cannot readily disperse to other waterways. Gharials are impacted by fishing pressure in two ways: the lack of prey due to overfishing and accidental capture in gill nets of adult and subadult individuals. Gharials are also persecuted by local fishermen and hunted for their ‘ghara’, penises and fat for use in traditional medicine. Finally, local tribes collect the eggs of gharials for food.

Back in the 1960s, up to 10,000 adult gharials were estimated to live around the great rivers in the north of the Indian subcontinent. Today, their total number in Nepal does not exceed 150 adult individuals, of which only 10% are males. The best current estimates suggest there are around 450 wild adult gharials left on Earth. The main threats to this species are river pollution, dam construction, and massive-scale fishing operations. Other serious problems include illegal sand mining, which destroys gharial egg-laying grounds, and poaching. The last refuge of the gharial is the Chambal River in northern India, where the vast majority of the remaining wild population survives.

Because of their weak leg muscles, gharialsare poorly equipped for locomotion on land. Most of their movement takes place in the water. When they do move across land, gharials push their bodies forward across the ground, a motion known as belly-sliding.

The gharial is one of the largest of all crocodilian species, with males reaching 5 to 6 meters (16 to 20 feet) in length. Females typically grow to lengths of 3.5 to 4.5 meters (11.5 to 15 feet).

Adult gharials primarily eat fish, while juveniles also feed on insects, crustaceans and frogs. The crocodile's unique snout, along with its sharp, interlocking teeth help it capture prey, quickly striking at fish in the water.

As with all crocodilians, the sex of the hatchlings is determined during incubation. Females, who are protective of their nest and hatchlings, provide the sole parental care.

Gharials last shared a common ancestor with the false gharial around 20 million years ago and, together, they diverged from all other crocodilians more than 40 million years ago. This was around the same time humans last shared a common ancestor with capuchin and squirrel monkeys.

The Critically Endangered gharial is an unmistakable crocodile on the brink of extinction. It has long, thin jaws which it uses to catch fish and males have a large, bulbous growth, known as a ‘ghara’, on the tip of their snout.

Gharials are the only crocodiles with such an obvious difference between males and females. These large crocodiles were once widespread across the Indian subcontinent but are now restricted to as few as five severely fragmented and depleted populations across India and Nepal.

Historically, the gharial's range spanned rivers of Bangladesh, Bhutan, India, Myanmar, Nepal and Pakistan. Today, only fragmented populations remain in Nepan and northern India.

Gharials are adapted to an aquatic lifestyle in large rivers, and individuals typically only leave the water to bask and nest on sandbanks.

Gharials might be incredibly protective parents, but they are not typically a danger to humans. Gharials are very shy and will typically hide from humans.

In just 60 years, the number of this species has decreased by 98%. The best current estimates suggest there are around 450 wild adult gharials left on Earth.

Do you think it is important to preserve the crocodile, which is one of the best helpers of man, because it is this crocodile that eats predatory fish, which eats fish that a person eats? Do you think it is important to preserve a species that is more than 40 million years old? Do you see a problem? What should be done to solve this problem?

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