A fossil fish that predates dinosaurs and was thought to have gone extinct has been found alive in the West Indian Ocean off the coast of Madagascar.

The fish named coelacanth was accidentally rediscovered by a group of South African shark hunters, according to reports.

According to a report by Mongabay News, the rediscovery was largely possible due to the fishermen's use of gillnets in their shark-hunting expeditions.

The high-tech deep-sea nets were able to reach the area where coelacanths gather, usually about 328-492 feet below the surface of the water.

Coelacanths predate dinosaurs but they resurfaced from extinction in 1938. Since then, this was the first instance that the fish was found alive. The recent re-discovery was a shock for scientists. They were able to identify it as a member of the "Latimeria chalumnae" species with its eight fins, a large body, and a specific pattern on its scales.

Now, marine scientists are calling for reinforcement of conservation measures to protect the fish.

It is believed the rediscovery of the fish has come in the wake of the ongoing increased demand for shark fins and oil. The demand has increased the use of gill nets, which can go deeper than regular fishing nets.

“When we looked into this further, we were astounded [by the numbers caught]… even though there has been no proactive process in Madagascar to monitor or conserve coelacanths,” said Andrew Cooke, lead author of a recent study published in the South African Journal of Science.

However, the journal noted that the fish might face new threats to survive with the increase in shark hunting in international waters.

"The jarifa gillnets used to catch sharks are a relatively new and more deadly innovation as they are large and can be set in deep water," the researchers wrote in the paper.