Fishermen in central Philippines have cooked and eaten a megamouth shark they caught not knowing it was a very rare fish, according to the World Wildlife Fund-Philippines.

The four-meter-long, 500-kilogram shark was caught on March 30 along the eastern coast of Burias Island, the conservation group said Tuesday, according to the Philstar.com. The group said it will launch a campaign to educate locals on the rare species as the area may yield more megamouth sharks aside from whale sharks, dolphins and giant manta rays.

Gregg Yan, WWF-Philippines information officer, told Philstar.com the latest catch would become the world's 41st megamouth. Citing records of the Florida Museum of Natural History, he said only 40 megamouths had been found in the world since the first kind was caught off Oahu in Hawaii in 1976.

The megamouth is different from other sharks because it has enormous maw that measures one meter wide and lined with a brilliant silver band used for filter feeding on planktons.