Manta rays do not have a functional barb or sting on their tail. This has given rise to their alternative common name of ‘devilfish’. While rolled up, giant manta rays' cephalic fins resemble horns. They use these for feeding, and roll them up to improve swimming efficiency when not in use. Giant manta rays have diamond-shaped bodies and two large muscular fins that protrude forward from the head either side of their mouth. But divers have occasionally been towed through the water at high speeds when mantas have become accidentally tangled in their float lines. They can also beat them in opposite directions – one up, one down.Īlthough once thought to migrate seasonally to the waters around northern New Zealand, research on other populations in the Indo-Pacific region suggests that the giant manta seen in our waters during spring and summer each year may be resident in this part of the southwest Pacific. Scientists points out that sharks and rays are the indicators that the fisheries reach unsustainable level and if no action is taken, more oceanic creatures would face extinction.Giant manta rays ( Mobula birostris) have huge, diamond shaped bodies and swim by beating their ‘wings’ up and down together. “But it is sad the same attention is not given to ocean creatures such as manta ray, even though they have the same threatened levels,” Mr Fernando noted.Ī recent global assessment which was done over years found that a third of shark and ray species have been overfished to near extinction. In Sri Lanka, the elephant and leopard are categorised as ‘endangered’ and there is a big uproar when such animals get killed. This species is already categorised as ‘endangered’ in the global red list,” Mr Fernando told the Sunday Times. The fish was elevated to the ‘endangered’ list only in 2020. “So, when we catch manta ray unsustainably, their population quickly declines. The female usually gives birth to a single pup and it has about a 12-month gestation period, records show. Manta ray, like most sharks, are slow breeders. But they often become by catch in commercial fishing. These are being used in traditional Chinese medicine, so there is a demand for the dry gill rakers, which also has led to them being purposely targeted. Manta rays filter feed using gill plates, which are cartilage filaments. Research has found that manta rays feed on plankton, filtering them through the ocean waters as they swim with their mouths open, but they also feed on fish on occasions. So in that sense, the one caught in Mirissa could have grown to be a bigger creature. It can weigh about 3,000 kg, but the average size is 4.5m (15 ft). Rays and skates are usually bottom dwellers, but the manta rays glide in open oceans, so it is also called oceanic manta ray, says Mr Fernando.įorty-two species of rays are known to live in Sri Lankan waters both inshore and in the ocean and the giant manta ray is the largest of them all.Īccording to available literature, the giant manta ray can grow to a disc size of up to 7 m (23 ft) across. The creature could have a greater economic value alive than the Rs.170,000 it was sold for, according to experts. Manta rays are a migratory species, so the one caught by the Mirissa fishermen could be one that was part of an attraction elsewhere. In the Maldives, rays are a key tourist attraction and operators for manta ray watching are estimated to generate over US$73 million a year with a direct economic impact, including associated tourism earnings of US$140 million a year, according to a 2013 study on ‘The Global Economic Impact of Manta Ray Watching Tourism’. Manta rays are an important attraction in marine tourism because of their enormous size and they are easily drawn to humans. He confirmed that what was caught by Mirissa fishermen was a giant manta ray, scientifically called mobula birostris. “But manta ray is a marvel of nature, and it would be worth more alive,” said Daniel Fernando of the Blue Resources Trust, an expert on rays and sharks. The giant Manta Ray Pic by Tharanga Gunarathne It took about 15 hours for the boat to reach Mirissa harbour, according to its skipper Ranjith Abeysundara. The fish was netted about 25 nautical miles offshore, so dragging it back to shore was a struggle. To offload the 800 kilogram fish, they had to use a backhoe. They hauled in a giant manta ray and sold it for Rs 170,000. The ocean deity Poseidon would have heard their prayers. It is a difficult time for everyone, so the fishermen of the boat ‘Sehansa’ that left Mirissa harbour on May 1, prayed for a good catch.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |