![]() The Giant Manta Ray has no spots between the gill slits. The easiest way to distinguish live fish is by the presence of dark spots on the ventral surface medially between the gill slits of the Alfred Manta. The Giant Manta Ray and Alfred Manta, Manta alfredi, can be distinguised by a number of measurements but also by size, dentition and spine morphology. Long thought to have been a single wide-ranging species, Mobula birostris, the genus is now known to comprise two species. Two species of Manta are known from Australian waters. Giant Manta Rays are grey-blue to green-brown above. They have a very broad mouth, on either side of which are prominent fleshy extensions called cephalic lobes. The surface of the body is rough to touch. The species has one dorsal fin and a whip-like tail which lacks a sting. The disc of the Giant Manta Ray is wider than it is long. However, the trade of manta ray meat is not widespread.The Giant Manta Ray is the largest species of ray in the world. It is strongly threatened by the direct fishing and bycatch, and its skin, liver, meat and gill rakers are traded to some extent. Manta birostris is in the “vulnerable” category of the Red List of the International Union for Conservation of Nature (IUCN). The number of offspring that a female normally has is 1, and in some cases 2. The reproduction rate in manta rays is very low. The eggs develop inside the mother for about 12 months and they hatch right there, so the offspring are born alive. Then it transfers the sperm through one of its claspers or copulatory organs, so that fertilization is internal. The competition ends when she chooses a male. Long courtship that last for several days have been observed, with the presence of the so-called “mating trains” characterized by the formation of a row of several males who follow the movements of a receptive female, trying to mate with her. Meanwhile, males reach maturity when their disc width is about 4-4.5 meters. The female giant manta ray sexually matures around 8-10 years of age, although it may be a few years later. It has also been seen less in the company of other manta rays but it does visit cleaning stations regularly for other fish take care of removing parasites and dead skin. Possibly, Manta birostris is more migratory than Manta alfredi, because the latter tends to reside longer in specific areas. However, it is also able to acquire a considerable speed and dive to 1,000 meters deep. This species tends to navigate the ocean slowly and elegantly and often it is found on the surface of the water. It has been seen feeding near shore and offshore. It is also likely to visit coastal sites temporarily. Sometimes it has been seen on the sandy bottom and sea grass areas, but this is not as common. It has been seen around groups of islands, along coastlines, in shallow reefs and seamounts. This species prefers to be found offshore at depths of up to 120 meters but close to the ocean surface. In some areas its habitat overlaps with the reef manta ray. The giant manta ray lives in tropical, subtropical and temperate waters of the Pacific, Indian and Atlantic oceans, often in the area between 31 degrees north and 36 degrees south latitude. The pattern of spots is unique to each individual, and this is really helpful to identify each. The mouth is colored in a dark color, unlike the reef manta ray that has a white mouth. The edges of the pectoral fins are also usually shaded black. The upper body is black, dark brown or blue-gray while the lower region is white with presence of dark spots. The skin of Manta birostris is rough and covered with protective mucus. 1,350 kilograms is the weight that a giant manta ray can have, although other estimates suggest up to 2 tons.Ĭoloration. The width of the central disc measures up to 9 meters, but individuals have been reported having a measure of 9.1 meters. Its tail is thin and whip-like, lacking stingers. Inside the mouth there are teeth embedded only in the lower jaw. Its eyes are on the sides of a slightly concave head. Although it may be imperceptible at a quick glance, it has a small dorsal fin. Opposite to the mouth two structures project out called cephalic lobes that are useful when feeding. The giant manta ray has a diamond-shaped body, with a wide central “disc” and triangular pectoral fins that when moving in the sea seem to be wings beating. Its name refers to the most striking feature: it is the biggest ray species of them all and the largest manta ray, surpassing Manta alfredi or reef manta ray.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |