What is a manta ray? The manta ray (Manta birostris) is the largest ray and one of the largest living fish. Like sharks, rays have skeletons composed of cartilege, unlike other fish which have skeletons of bone. If you are lucky enough to see a manta ray underwater it is likely to be one of the most graceful sights you will encounter. However, they can also swim very fast and even leap clear of the water.

What does it look like? The manta ray can reach immense sizes of three to seven metres (with reports of large specimens measuring more than nine metres) from wing tip to wing tip. They are greyish blue to greenish brown on the upper surface and pale underneath. Manta rays have prominent feeding flaps—fleshy extensions of the pectoral fins—on each side of the head. The eyes are at the top of these flaps. There are five gill slits on each side of the underside of the head. The whip-like tail is relatively short and there is no stinging spine. Males can be identified by a pair of external claspers. You can often see remoras or suckerfish attached to manta rays. The suckerfish have a large sucking disk on the top of the head with which they attach themselves to larger fish. These ‘hitchhikers' benefit from feeding on scraps of food dropped by the host or feed on skin parasites.

Vision courtesy of MIRG Australia (www.mirg.org.au)/Blue Office Productions 

Where does it live? Manta rays are found over areas of continental shelf throughout the world's tropics and subtopics. The manta ray is very common in tropical waters of Australia, including Ningaloo Marine Park, Muiron Islands Marine Management Area, Montebello Islands Marine Park, Eighty Mile Beach Marine Park, Lalang-garram / Camden Sound Marine Park and Rowley Shoals Marine Park. Many visitors to Ningaloo Marine Park see and even swim with these large rays on the western side of Ningaloo Reef where they are relatively common. Charter operators at Ningaloo offer tours to snorkel with the mantas. Manta rays occasionally find their way into temperate waters and one was photographed as far south-east as the Walpole and Nornalup Inlets Marine Park in 2007.

What they eat and how: The manta ray is a harmless filter feeder, taking in water and food through its mouth . It only has very small teeth, but has modified denticles on each gill arch that is used to filter plankton from the water.

Behaviour: Manta rays are often seen in groups and spend a lot of time near the surface.

Breeding and caring for young: The young are enclosed in a thin shell which hatches inside the mother.

Conservation status: The International Union for the Conservation of Nature (IUCN) considers the manta ray to be 'near threatened' because of its low reproductive rate. In some parts of the world manta rays are fished for food or medicine. However, in Australia, manta ray populations are believed to be fairly secure and are not recorded as making up a significant component of by-catch from commercial fishing operations.

Protecting the manta ray: We can look after the manta ray by protecting its habitat and the water quality in areas where it lives. Western Australia's marine parks and reserves help to protect important habitat for manta rays.