Whitefin swellshark facts for kids
Quick facts for kids Whitefin swellshark |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Cephaloscyllium
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| Species: |
albipinnum
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The whitefin swellshark (Cephaloscyllium albipinnum) is a special type of catshark. It belongs to the family called Scyliorhinidae. This shark lives only in southeastern Australia, which means it is endemic there.
You can find these sharks deep in the ocean, from about 126 to 554 meters (413 to 1,818 feet) down. They live on the outer edge of the continental shelf and the upper continental slope. Whitefin swellsharks can grow up to 1.1 meters (3.6 feet) long. They have a very thick body and a short, wide, flat head with a big mouth.
One cool thing about them is their color. They have dark saddle-like marks and blotches on their brown or gray bodies. Their fins also have light edges, which is how they got their name! When these sharks feel scared, they can puff themselves up with water or air. This makes them look much bigger to scare away predators.
Like some other sharks, they lay eggs. The International Union for the Conservation of Nature (IUCN) has said that the whitefin swellshark is Critically Endangered. This means their numbers have dropped a lot, and they need our help to survive.
Contents
How it Got its Name
For a while, people sometimes confused the whitefin swellshark with other sharks. These included the Australian swellshark or the draughtsboard shark.
In 1994, scientists realized it was a new species. They called it Cephaloscyllium "sp. A" for a time. Then, in 2008, three scientists named Peter Last, Hiroyuki Motomura, and William White officially described it. They published their findings through the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
Its special name, albipinnum, comes from Latin words. Albi means "white," and pinna means "fin." This name perfectly describes its unique white fin edges! The first shark used to describe the species was a 1.0 meter (3.3 feet) long adult male. It was caught near Maria Island, Tasmania.
What it Looks Like
The whitefin swellshark is a sturdy shark that can grow up to 1.1 meters (3.6 feet) long. Its head is short, very wide, and quite flat, with a rounded snout. Its eyes are like slits and are placed high on its head. Behind the eyes are tiny holes called spiracles.
Its nostrils have small flaps of skin in front of them. The shark has a large, curved mouth without grooves at the corners. It has many rows of teeth, about 90 to 116 in the upper jaw and 97 to 110 in the lower jaw. Each tooth has three main points and sometimes one or two smaller points on the sides. You can see its upper teeth even when its mouth is closed.
The shark has five pairs of gill slits. The fourth and fifth pairs are shorter and are located above the bases of its pectoral fins.
Fins and Skin
The pectoral fins are large and wide. The first dorsal fin (on its back) is rounded and starts over the front half of its pelvic fins. The second dorsal fin is much smaller and shaped a bit like a triangle.
The pelvic fins are small. Male sharks have very long parts called claspers. The anal fin is bigger than the second dorsal fin. It is rounded in young sharks but becomes more angled in adults. The large caudal fin (tail fin) has a clear lower part and a deep notch near the tip of the upper part.
The shark's skin is thick and feels rough. This is because of small, arrowhead-shaped scales called dermal denticles. These scales have three ridges. The top of the shark is brown to gray. It has 9 to 10 dark saddle-like marks that switch with dark blotches on its sides. One large round blotch covers its gill slits. Its fins are dark on top but have light edges. The shark's belly is lighter than its back. Young sharks have clearer and more regular blotches than adult sharks.
Where it Lives
The whitefin swellshark lives off southeastern Australia. You can find it from Batemans Bay, New South Wales all the way to the Great Australian Bight. This includes southern Tasmania, from Maria Island to Point Hibbs.
This shark is a bottom-dweller. It lives on the outer part of the continental shelf and the upper part of the continental slope. It prefers depths between 126 and 554 meters (413 to 1,818 feet).
Biology and Reproduction
Like other sharks in its group, the whitefin swellshark has a cool defense trick. When it feels threatened, it can quickly swallow water or air. This makes its body swell up a lot, making it look much bigger. This sudden size increase can scare away predators.
The whitefin swellshark lays eggs, which means it is oviparous. Its eggs are inside smooth, light yellow capsules. These capsules are shaped like flasks and are about 9.8 to 11.6 centimeters (3.9 to 4.6 inches) long and 5 centimeters (2.0 inches) wide. They have flat edges and short "horns" at the corners. These horns have long, curly threads that help the egg case attach to things on the seafloor.
Male whitefin swellsharks become mature when they are about 70 centimeters (28 inches) long. Females become mature when they are about 98 centimeters (39 inches) long.
Human Interactions and Conservation
The whitefin swellshark lives in an area where a lot of fishing happens. Even though people don't specifically fish for them, these sharks are often caught by accident. This is called bycatch, especially in trawl fishing nets.
The Australian South East Trawl Fishery operates in over a third of this shark's habitat. They reported that the number of whitefin swellsharks caught dropped by more than 30% between 1967–77 and 1996–97. Another program, the South East Trawl Fishery Observer Program, also saw a small drop in their population off southern Australia.
Because of these declines, the International Union for the Conservation of Nature (IUCN) has listed the whitefin swellshark as critically endangered. This means it faces a very high risk of disappearing from the wild. The IUCN has suggested that we need to carefully watch how many sharks are caught as bycatch to help protect this species.
See also
In Spanish: Cephaloscyllium albipinnum para niños
