They keep close to the surface and in shallow water in daytime, while at night they swim at greater depths. Mantas are common around coasts from spring to fall, but travel further offshore during the winter. Seasonal migrations do occur, but they are shorter than those of M. alfredi is a more resident and coastal species. birostris lives mostly in the open ocean, travelling with the currents and migrating to areas where upwellings of nutrient-rich water increase prey concentrations.įish that have been fitted with radio transmitters have travelled as far as 1,000 km (620 mi) from where they were caught and descended to depths of at least 1,000 m (3,300 ft). alfredi is predominantly found in tropical areas. They prefer water temperatures above 68 ☏ (20 ☌) and M. The furthest from the equator they have been recorded is North Carolina in the United States (31ºN) to the north, and the North Island of New Zealand (36ºS) to the south. Mantas are found in tropical and subtropical waters in all the world's major oceans and also venture into temperate seas. Individual mantas may revisit the same cleaning station or feeding area repeatedly and appear to have cognitive maps of their environment. alfredi visits cleaning stations more often than M. In Mozambique, sergeant major fish clean the mouth while butterflyfishes concentrate on bite wounds. In Hawaii, wrasses provide the cleaning some species feed around the manta's mouth and gill slits while others address the rest of the body surface. Such visits most frequently occur when the tide is high. The ray adopts a near-stationary position close to the coral surface for several minutes while the cleaner fish consume the attached organisms. Mantas visit cleaning stations on coral reefs for the removal of external parasites. They may also be bitten by cookiecutter sharks, and harbor parasitic copepods. Mantas are themselves preyed upon by large sharks and by killer whales. As many as fifty individual fish may gather at a single, plankton-rich feeding site. While feeding, mantas flatten their cephalic fins to channel food into their mouths and the small particles are collected by the tissue between the gill arches. If a ball is particularly dense, a manta may somersault through it. When foraging, it slowly swims around its prey, herding it into a tight "ball" and then speeds through the bunched organisms with a wide-open mouth. An individual manta eats about 13% of its body weight each week. Manta alfredi at a coral reef cleaning station with fish picking off parasitesĪs filter feeders, manta rays consume large quantities of zooplankton in the form of shrimp, krill and planktonic crabs. alfredi has been shown to dive to depths of over 400 m, while their relative Mobula tarapacana, which has a similar structure, dives to nearly 2000 m the retia mirabilia probably serve to prevent their brains from being chilled during such dives into colder subsurface waters. Their brains have retia mirabilia which may serve to keep them warm. They have one of the highest brain-to-body mass ratios and the largest brain size of all fish. Mantas track down prey using visual and olfactory senses. The fish's gill arches have pallets of pinkish-brown spongy tissue that collect food particles. The cephalic fins are usually spiralled, but flatten during foraging. The spiracles typical of rays are vestigial, and mantas must swim continuously to keep oxygenated water passing over their gills. Their large mouths are rectangular, and face forward as opposed to other ray and skate species with downward-facing mouths. Mantas move through the water by the wing-like movements of their pectoral fins, which drive water backwards.
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