Lobed stingaree facts for kids
Quick facts for kids Lobed 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. lobatus
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| Binomial name | |
| Urolophus lobatus McKay, 1966
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The lobed stingaree (Urolophus lobatus) is a common type of stingray. It belongs to the family Urolophidae. This stingray is only found in southern Western Australia. It lives in shallow, inshore sandy areas and seagrass beds.
This stingray is usually a plain sandy color on top. It has wide, rounded side fins. A special feature is a large, half-circle shaped skin flap on the inside of each nostril. Scientists are not sure what these flaps are for. Its tail is thin with skin folds on the sides. It has a spear-shaped tail fin but no back fin. The biggest lobed stingaree found was about 27 cm (11 in) wide.
The lobed stingaree is a bottom-dwelling hunter. It mostly eats crustaceans, like crabs and shrimp. It also eats small bony fish, polychaete worms, and molluscs. This stingray gives birth to live young. The babies get food from "uterine milk" inside the mother. Females usually have one baby every October or November. Their pregnancy lasts about ten months.
In the northern part of its home, fishing boats sometimes catch these stingarees by accident. Even though they usually survive, they often lose their babies when caught. However, people do not affect this species much overall. The International Union for Conservation of Nature (IUCN) says it is a species of Least Concern. This means it is not threatened.
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How it Got its Name
An Australian fish scientist named Roland McKay first described the lobed stingaree. He wrote about it in 1966. He gave it the scientific name lobatus because of its special nasal lobes. The first example of this stingray was found near Rottnest Island in Western Australia. It was found about 31–33 m (102–108 ft) deep.
Where it Lives
The lobed stingaree is one of the most common stingrays in its family. It lives along a short part of the southwest Australian coast. You can find it from Esperance to Rottnest Island. This stingray lives on the ocean floor. It likes sandy areas and seagrass beds. It can be found from the area between high and low tide down to 30 m (98 ft) deep.
In the southern part of its home, it tends to live further from the shore. Young and old stingarees, and males and females, all live together.
What it Looks Like
The lobed stingaree has rounded pectoral fins (side fins). These fins are much wider than they are long. The front edges of these fins are almost straight. Its snout is soft and rounded. The tip might stick out a little past the main body disc.
Its medium-sized eyes are followed by tear-shaped spiracles. These are like breathing holes. The outer back corner of each nostril has a clear lobe. Between the nostrils is a skin flap shaped like a skirt. This flap has a fringed edge. The front corners of the flap are larger and form unique, half-circle lobes.
The mouth is small. It has 9 to 10 small bumps, called papillae, on its floor. A few papillae are also on the lower jaw. Its small teeth have oval bases. It has five pairs of short gill slits. The pelvic fins (belly fins) are small and rounded.
The tail is thin and very flat. It is almost as long as the body disc. It has a clear horizontal skin fold on each side. There is a stinging spine on its back near the caudal fin (tail fin). This spine has jagged edges. The tail fin is long, narrow, and shaped like a leaf. There is no dorsal fin (back fin).
Its skin does not have any tiny, tooth-like scales. The stingray is yellowish-brown on top. It gets a bit lighter at the sides. Its underside is white. Some stingarees have dark spots or a dark stripe along the middle of their tail. The tip of the tail fin gets dark. Males can grow up to 24 cm (9.4 in) wide. Females can grow up to 27 cm (11 in) wide.
Life Cycle and Reproduction
Like other stingrays, the lobed stingaree gives birth to live young. The females have one working uterus (womb) on the left side. They have one breeding cycle each year. Mating happens in November and October. Eggs are released from mid-November to mid-January. This means females store sperm inside for 1 to 3 months before the eggs are fertilized.
The pregnancy lasts ten months. Even though up to six eggs might be fertilized, usually only one baby develops. Sometimes, two babies develop. The baby stingray first gets food from a yolk sac. By five months old, the baby is about 5.4 cm (2.1 in) wide. It has moved most of the remaining yolk into its digestive system.
By six months old, the mother starts to give the baby nutrient-rich "uterine milk." This milk comes through special threads from the uterus lining. These threads grow into the baby's mouth, gills, and spiracles. The baby's body and tail are folded to hold the sting close to its body.
Babies are born in late October or early November. Newborns are about 11 cm (4.3 in) wide. Females grow slower but get bigger than males. Males are ready to have babies when they are about 16 cm (6.3 in) wide and two years old. Females are ready when they are about 20 cm (7.9 in) wide and three years old. Males can live up to 12 years. Females can live up to 14 years.
What it Eats
Almost 90% of the food the lobed stingaree eats is crustaceans. These include small shrimp-like creatures called mysids, amphipods, and cumaceans. They catch these on or just above the ocean floor. This stingray also eats polychaete worms, small bony fish, and sometimes molluscs.
Smaller stingrays (less than 19 cm (7.5 in) wide) eat more mysids, amphipods, and cumaceans. Larger stingrays eat more shrimps and fish. They also have a wider variety of foods in their diet. What they eat also changes with the seasons. This is because shrimp are more available in summer and fall. Cumaceans are more available in winter and spring. A type of tapeworm can be a parasite of this stingray.
Stingarees and People
Boats fishing for scallops and prawns sometimes catch the lobed stingaree by accident. This happens off Perth and Mandurah in the northern part of its range. The stingray usually survives and is released alive. However, stingrays often lose their babies when they are caught.
Not many boats catch this species. Also, it does not face many other big threats where it lives. Because of this, the International Union for Conservation of Nature (IUCN) says the lobed stingaree is of Least Concern. This means it is not in danger. A plan from 2004 to help sharks and rays in Australia could also help this species.
