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Manta Ray Season
The manta ray, or giant manta (Manta birostris),
is the largest of the rays,
with the largest known specimen having been nearly 7.6 meters (25 ft)
across its pectoral fins (or "wings") and weighed in at 3,000 kg (6,600
lb). It ranges throughout the tropical seas of the world, typically
around coral reefs.
Mantas are most commonly black above and white below, but some are blue
on their backs. A giant manta's eyes are located at the base of the
cephalic lobes on each side of the head, and unlike other rays the
mouth is found at the anterior edge of its head. To breathe, like other
rays, the manta has five pairs of gills on the underside.
With distinctive "horns" (from which the common name 'devil ray'
stems), on either side of its broad head, the manta is a prized
sighting by divers. These unique structures are actually derived from
the pectoral fins. During embryonic development, part of the pectoral
fin breaks away and moves forward, surrounding the mouth. This gives
the Manta Ray the distinction of being the only jawed vertebrate to
have novel limbs (the so-called six-footed tortoise (Manouria emys)
does not actually have six legs, only enlarged tuberculate scales on
their thighs that look superficially like an extra pair of hind limbs).
These flexible horns are used to direct plankton, small fish and water
into the Manta's very broad and wide mouth. The manta can curl them up
to reduce drag while swimming.
Manta Rays may have evolved from bottom feeding ancestors but have
adapted to become filter feeders in the open ocean. This has allowed
them to grow to a larger size than any other species of ray. Because of
their pelagic lifestyle as plankton feeders, some of the ancestral
characterstics 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 denticals are also greatly reduced in
number and size, but are still present, and 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.
To swim better through the ocean, they have a diamond shaped body plan, using their pectoral fins as graceful "wings".
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. The small prey organisms are caught
on flat horizontal plates of russet-coloured spongy tissue, that span
the spaces between the manta's gill bars.
Mantas frequent reef-side cleaning stations where small fish such as wrasses and angelfish
swim inside the manta's gills and all over its skin to feed, in the
process cleaning it of parasites and removing bits of dead skin.
The predators of the Manta Ray include mainly large sharks, however
in some circumstances killer whales have also been observed preying on
them.
Taxonomically, the situation of the mantas is still under investigation. Three species have been identified: Manta birostris, Manta ehrenbergii, and Manta raya, but they are quite similar to each other, and the last two may just be isolated populations. The genus Manta is sometimes placed in its own family, Mobulidae, but this article follows FishBase, and places it in the family Myliobatidae, with the eagle rays and their relatives.
Mantas have been given a variety of common names, including Atlantic manta, Pacific manta, devil ray, devilfish, and just manta. Some people just call all members of the family stingrays.
Mantas are extremely curious around humans, and are fond of swimming
with scuba divers. They have the biggest brains of any fish. [citation needed]
The Moche people of ancient Peru worshipped the sea and its animals. They often depicted manta rays in their art. [1] Information from Wikepedia-http://en.wikipedia.org/wiki/Manta_ray |