Page 587 - The British Big Four
P. 587
Eagle Rays, Manta Rays and Stingrays
agle Rays - Eagle rays feed on mollusks and crustaceans, crush- anta Rays - The larger species, M. birostris, reaches 7 m (23
ft) in width while the smaller, M. alfredi, reaches 5.5 m (18
E ing their shells with their flattened teeth, while devil and manta
Mrays filter plankton from the water. They are excellent swimmers
and are able to breach the water up to several metres above the ft). Both have triangular pectoral fins, horn-shaped cephalic fins
surface. Compared with other rays, they have long tails, and well- and large, forward-facing mouths. The largest mantas can reach
defined rhomboidal bodies. They are ovoviviparous, giving birth to 1,350 kg (3,000 lb). Manta rays are known for their large size, broad
up to six young at a time. They range from 48 centimetres (19 in) heads, triangular pectoral fins, and the horn-shaped cephalic fins
to 9.1 metres (30 ft) in length. The spotted eagle ray, Aetobatus located on either side of their mouths. The name “manta” is Span-
narinari, also known as the bonnet ray or maylan, belongs to this ish for cloak or blanket, a type of blanket-shaped trap tradition-
genus. The ray bears numerous white spots on its inky blue body. ally used to catch rays. They are protected in international waters
It has a span width of 2.5 m (8 ft) and a maximum reported weight by the Convention on Migratory Species of Wild Animals, but are
of 230 kg (about 507 lbs). Including the tail, it can reach up to 5 m more vulnerable closer to shore. Areas where mantas congregate
(16 ft) in length. The spotted eagle ray is found in the tropical areas are popular with tourists. Only a few aquariums are large enough
of all oceans, including the Caribbean Sea and the Gulf of Mexico. to house them. In general, these large fish are seldom seen and dif-
The genus also includes the much smaller longheaded eagle ray, ficult to study. Manta rays are Chondrichthyes, fish with tough car-
Aetobatus flagellum, which is a widespread but uncommon species tilage rather than bone in their skeletons. As filter feeders, manta
of Indian Ocean and western Pacific coasts. This is considered an en- rays consume large quantities of zooplankton in the form of shrimp,
dangered species due to huge pressure from fisheries throughout krill and planktonic crabs. An individual manta eats about 13% of its
its range. Eagle rays live close to the coast in depths of 1 to 30 m body weight each week. The greatest threat to manta rays is over-
and in exceptional cases they are found as deep as 300 m. The eagle fishing. In 2011, mantas became strictly protected in international
ray is most commonly seen cruising along sandy beaches in very waters thanks to their inclusion in the Convention on Migratory
shallow waters, its two wings sometimes breaking the surface and Species of Wild Animals.
giving the impression of two sharks traveling together.