Concerned Divers for the Philippines – International Coastal Cleanup 2009
Diving from Crystal Blue Resort, Anilao, Batangas… we went across to Maricaban Island and cleaned Caban Cove…
Concerned Divers for the Philippines – International Coastal Cleanup 2009
Diving from Crystal Blue Resort, Anilao, Batangas… we went across to Maricaban Island and cleaned Caban Cove…
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The manta ray (Manta birostris), is the largest of the rays, with the largest known specimen having been more than 7.6 m (about 25 ft) across, with a weight of about 2,300 kg (about 5,000 lb). It ranges throughout tropical waters of the world, typically around coral reefs.
Mantas have been given a variety of common names, including Atlantic manta, Pacific manta, devilfish, and just manta. Recent studies have suggested that what is called manta ray are at least two different species, one smaller local and one much larger and migratory
Manta rays may have evolved from bottom-feeders, and then adapted to become filter feeders in the open ocean. This allowed them to grow larger than other ray species. Due to being plankton feeders, some of the ancestral characteristics have degenerated. For example, all that is left of their oral teeth is a small band of vestigial teeth on the lower jaw, almost hidden by the skin. Their dermal denticles are also greatly reduced in number and size but are still present. They have a much thicker body mucus coating than other rays. Their spiracles have become small and non-functional, as all water is taken in through their mouth instead.
Mantas are filter feeders: they feed on plankton, fish larvae and the like, passively filtered from the water passing through their gills as they swim. Small prey organisms are caught on flat horizontal plates of russet-coloured spongy tissue spanning spaces between the manta's gill bars.
Mantas frequent reef-side cleaning stations where small fish such as wrasses and angelfish swim in the manta's gills and over its skin to feed, in the process cleaning it of parasites and removing dead skin.
The predators of the Manta ray are mainly large sharks, however in some circumstances orcas have also been observed preying on them.
Mantas are extremely curious around humans, and are fond of swimming with scuba divers. Although they may approach humans, if touched, their mucus membrane is removed, causing lesions and infections on their skin. They often surface to investigate boats without engines running. They have the largest brain-to-body ratio of the sharks and rays.
Mantas are known to breach the water into the air.
Photo taken by Alberto at German Channel in Palau - 08Apr2008
cool! reposted this to my site
-agnes