Greenback stingaree facts for kids
Quick facts for kids Greenback stingaree |
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| Conservation status | |
| Scientific classification | |
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Urolophidae
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| Genus: |
Urolophus
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| Species: |
U. viridis
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| Binomial name | |
| Urolophus viridis McCulloch, 1916
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The greenback stingaree (Urolophus viridis) is a type of stingray. It belongs to the family Urolophidae. This special ray lives only off the coast of southeastern Australia.
It can grow up to 51 cm (20 in) long. The greenback stingaree has a flat, diamond-shaped body that is wider than it is long. It is usually light green on top. It has a unique curtain of skin between its nostrils. Its tail has skin folds on the sides and a deep, pointed fin at the end. Unlike some other rays, it does not have a fin on its back.
This stingaree usually lives on soft sand or mud at depths of 80–180 m (260–590 ft). It hunts and eats small worms and crabs. Female greenback stingarees give birth to live young. They have 1 to 3 babies each year after being pregnant for 10 to 12 months.
Sadly, many greenback stingarees are caught by accident in fishing nets. Most of these rays do not survive. Because of this, their numbers have dropped a lot. The International Union for the Conservation of Nature (IUCN) says the greenback stingaree is a Vulnerable animal. This means it is at risk of disappearing.
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What is a Greenback Stingaree?
The greenback stingaree was first described by an Australian scientist named Allan Riverstone McCulloch. He wrote about it in a science book in 1916. He named it viridis, which is a Latin word meaning "green."
The first greenback stingaree studied was found near Green Cape in New South Wales. It was caught at a depth of 90 m (300 ft). Scientists have also found a similar stingaree off southwestern Australia. It might be the same species, but it has slightly different fins.
Where Does the Greenback Stingaree Live?
The greenback stingaree used to be quite common. It lives in warm waters from Portland in Victoria up to Stradbroke Island off Queensland. It can also be found around all of Tasmania.
This stingaree lives deeper than most other stingarees in the area. It prefers the bottom of the ocean, usually on soft sand or mud. It is mostly found at depths of 80–180 m (260–590 ft). This is on the outer edge of the continental shelf and the upper part of the continental slope. Sometimes, it can be found in shallower water, as little as 20 m (66 ft) deep. It has also been seen as deep as 300 m (980 ft).
What Does the Greenback Stingaree Look Like?
The greenback stingaree has a body shaped like a diamond. It is wider than it is long. The corners of its body are rounded. The front edges of its body are almost straight and meet at a wide angle at its nose. Its nose sticks out a little bit.
It has large eyes, and behind them are comma-shaped holes called spiracles. These help it breathe. Between its nostrils, there is a curtain of skin that looks like a skirt. This curtain has a slightly fringed edge. Its mouth is medium-sized and has small, nipple-like bumps inside. Its teeth are small and oval-shaped. It has five pairs of short gill slits. Its bottom fins, called pelvic fins, are small and round.
The tail of the greenback stingaree is flat near its body. It is about 75% to 91% as long as its body. There is a clear skin fold along each side of the tail. At the very end of the tail, there is a deep, pointed fin. About halfway along its tail, there is a sharp, stinging spine. This ray does not have a fin on its back.
Its skin is smooth and does not have any rough scales. The top of the stingaree is a plain light green color. It gets lighter towards the edges of its body. The underside is off-white, but it can look purplish or pinkish towards the sides. The edges of its body underneath might also have dark brown spots. The tail fin is dark brown in young stingarees and olive green in adults. Some stingarees might have dark colors under their tail or on the tip of their nose. The biggest one ever recorded was 51 cm (20 in) long.
Life Cycle and Habits
The greenback stingaree mainly eats worms and crabs. It can also have tiny parasites, like a type of worm called Calicotyle.
Like other stingrays, the greenback stingaree gives birth to live young. The baby stingarees grow inside their mother. They are fed by a special liquid, sometimes called "uterine milk," that the mother produces.
Female stingarees usually have 1 to 3 babies each year. They are pregnant for about 10 to 12 months. Male stingarees become old enough to have babies when they are about 28 cm (11 in) long. Females are ready to reproduce when they are about 26–31 cm (10–12 in) long. Stingarees found near Lakes Entrance, Victoria, seem to be ready to reproduce at a smaller size than those in other areas.
Why the Greenback Stingaree Needs Our Help
The greenback stingaree is one of the most common stingarees caught by accident in fishing nets. This happens in the Southern and Eastern Scalefish and Shark Fishery (SESSF) off New South Wales. Other fishing operations in Queensland also catch them.
Because they live in deep water, greenback stingarees usually do not survive after being caught. Also, if a pregnant female is caught, she often loses her babies. We don't have exact numbers for this species alone. However, between 1976 and 1997, the number of stingarees on the upper slope of New South Wales dropped by about two-thirds.
Because their numbers are falling and fishing continues, the International Union for the Conservation of Nature (IUCN) has listed the greenback stingaree as Vulnerable. This means it is at high risk of becoming extinct. There is a plan from 2004 in Australia to help protect sharks and rays. This plan could also help the greenback stingaree.
