During the last few weeks we have encountered Manta Rays (Manta birostris) on nearly every dive at the popular dive sites Hin Daeng and Hin Muang, located close to Ko Lanta in Thailand. We observed at least 5 different individuals, some of which were seen and photographed over several days. The Manta’s name comes from the Spanish word for blanket and refers to their enormous size. They can grow up to 8m in width, up to 3 tons in weight and the maximum reported age of a specimen is 20 years. The world’s largest ray lives singly or in loose aggregations and is mainly found in or near shore areas where water is shallow. It is distributed circumtropical and feeds on plankton and small fish. Manta rays frequently visit cleaner stations, where wrasses and other species of fish clean the giant ray’s skin of parasites and dead skin.
The Manta’s that visit Hin Daeng and Hin Muang are almost certainly coming to be cleaned, as we investigated whilst diving with them over the last few days. At first, we observed the rays slowing down as they approached the reef – this is where the cleaner fish can be found in abundance. Then, once the wrasse realised that they were allowed to clean the Mantas, they swam inside the gills, close to the mouth and all over the ray’s body, to feed on the organisms that parasitize the giant. Hopefully the rays enjoy this treatment for some more time so we can enjoy the marveling at this fantastic Manta display!
It is also believed that Manta Rays and Whale Sharks use Hin Daeng and Hin Munag as a navigation point as they cruise around the tropics.
This really is the time of the year for the big stuff, with yet more Manta Rays cruising around Hin Daeng, south of Ko Lanta. This Manta was around 6m from wingtip to wingtip and stayed with us for the whole dive. Footage courtesy of Liquid Lense & Scubafish.