Giant freshwater stingray

Most likely the world’s largest freshwater fish, the giant freshwater stingray can weigh up to 600kg and grow to a length of 5m from nose to tail. Males are smaller than females, which can be eight times bigger. Despite its size, it is very elusive and very little is known about this mysterious fish.

It was first scientifically described in 1990 and up till now, next to nothing is known about this species, its numbers and behaviour. The population in the wild is dwindling due to pollution, habitat destruction and overfishing. Dams block their migratory routes.

Short-snouted and long-tailed, the flattened body and fins of this fish help it glide smoothly along the river bed. Patchy patterns on its back resemble sun-dappled river beds.

To avoid detection by predator and prey alike, it buries itself in sandy or silted river bottoms, breathing through holes, or spiracles, located on the top of its body. This laidback lifestyle gives even small individuals protection from larger predators.

Stingrays will not attack unprovoked but they are one of the few megafishes that pose a real danger to humans. Each ray has a deadly barb at the base of its tail. Coated with poisonous mucus, this large venomous stinger can be 28-38 cm long.

Much like a hunting arrow, it easily penetrates human skin and even bone, introducing toxins to the victim's wound strong enough to knock out an adult human.

This species is ovoviviparous, which means it bears live young. The mother carries her young inside her body, each nourished by egg yolk. Babies are born with a mucous plug at the end of their barb to protect the mother during birth!

Renowned conservationist and TV star, “Crocodile Hunter” Steve Irwin, was killed while on a shoot when a large bull ray attacked him with its barb. He was stung in the heart and died soon after the attack.

While stingray attacks are rarely fatal, they leave behind serious and painful wounds. In the attack on Steve Irwin, his death too was probably due to blood loss rather than the effects of the venom. Stingrays are usually shy animals and do not attack unless they feel threatened.