Sometimes known as sea devils, stingrays have venomous barbs on their tails. Marine biologist Jodie Peers is quick to defend her new charges: “They have the potential to kill, but it is just like with bees - their sting can be painful but it is rarely fatal.

“Rays are not at all vicious, but some hide in sand on the sea-bed and they can be stepped on - that’s when you could get hurt. Rays are sensitive and intelligent creatures, some are shy, others are more outgoing. I can identify all of our new arrivals individually. The two mangrove rays are quite boisterous characters. I hope we will have breeding here in the longer term.”

Rays are tropical marine fish related to skates and sharks. Some grow no larger than a human hand, while others can be six metres in diameter. They move using their large pectoral fins (commonly known as wings). A group of stingrays is known as a fever.

As their eyes are on top of their bodies and their mouths underneath, they never see their prey, but use smell and electro-receptors similar to those of sharks. They feed mainly on molluscs and crustaceans.

The blue-spotted ribbontail ray

The blue-spotted ribbontail ray (Latin name Taeniura lymma) is found around the coral reefs of the West Pacific, Red Sea, East Africa, Japan and Australia. It feeds in shallow sandy areas in small groups during the rising tide. It gives birth to fully-formed babies and can grow up to 30cm, with the length of the tail doubling this.

The colour varies from grey-brown to yellow, or olive-green to reddish brown on the dorsal side, but they are white underneath. At present it is widespread and common, but this species is subject to population decreases because of indiscriminate capture for the fish trade and because of the destruction of the reefs in which they live. The official conservation status is Near Threatened.

The blue-spotted stingray

The blue-spotted stingray (Dasyatis khulii) is generally found in tropical coastal reefs and estuaries. A solitary species, it is often found buried in sand or mud with only the eyes showing. It grows to a disc width of 40cm and a total length of 70cm. This species (also known as the masked stingray) can be recognised by its grey/brown body covered in large electric blue spots. This species lays just a few eggs which the female retains before giving birth to live young. This species is often taken as unwanted by-catch by trawlers. Official conservation status is Near Threatened.

The mangrove whipray

The mangrove whipray (Himantura granulata) lives in reefs and mangroves. Its distribution is not fully known, but includes the West Pacific, Maldives, Seychelles New Guinea, Santa Cruz and Solomon islands. It can grow to almost 1 metre in diameter. This fish is caught for its meat. In the past it has been taken for its skin and cartilage - for example by the Aborigines of Australia. It can swim forwards and slowly backwards by undulating its pectoral fins around the body disc. Its tail is used for steering and balance but also support the defensive tail sting. When escaping a predator the stingray is able to sacrifice the very tip of its tail. Its gills are on the underside of its body, which makes breathing difficult when hidden in sand. To overcome this, it has developed a large opening just behind the eye which sucks in oxygen-rich water to flow over the gills, meaning it can stay under the sand for some time. Conservation status - not evaluated

These animals are part of a new exhibit called 'Mangroves: The Roots of the Sea' which will open on 16th July.