MANILA, Philippines - Fishermen in the Philippines accidentally caught and later ate a megamouth shark, one of the rarest fishes in the world with only 40 others recorded to have been encountered, the World Wildlife Fund said Tuesday.

The 1,100-pound (500-kilogram) 13-foot (4-metre) megamouth died while struggling in the fishermen's net on March 30 off Burias island in the central Philippines. It was taken to nearby Donsol in Sorsogon province, where it was butchered and eaten, said Gregg Yan, spokesman for WWF-Philippines.

Yan said a WWF Donsol Project Manager Elson Aca took pictures of the megamouth and tried to dissuade the fishermen from eating it. Shark meat is the main ingredient in a local delicacy.

The first megamouth was discovered in Hawaii in 1976, prompting scientists to create an entirely new family and genus of sharks. The megamouths are docile filter-feeders with wide, blubbery mouths. Yan said the Burias megamouth's stomach revealed it was feeding on shrimp larvae.

Yan said the fish was tagged "Megamouth 41" -- the 41st megamouth recorded in the world -- by the Florida Museum of Natural History. It was the eighth reported encountered in Philippine seas.

He said the megamouth was caught in 660-foot (200-meter) deep waters, which are also frequented by the endangered whale shark, the world's largest fish and also a filter-feeder in the Donsol area, about 185 miles (300 kilometers) southeast of Manila.

Aca said the presence of two of the world's three filter-feeding sharks along with manta rays and dolphins indicates that the region's marine ecosystem was still relatively healthy and should continue to be protected.

Yan urged fishermen who encounter the rare shark to immediately report to authorities or the WWF.

Others megamouths have been encountered in California, Japan, Taiwan, Indonesia, Brazil, Ecuador, Senegal, South Africa, Mexico and Australia.