Pygmy ribbontail catshark facts for kids
Quick facts for kids Pygmy ribbontail catshark |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Eridacnis
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| Species: |
radcliffei
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| Range of the pygmy ribbontail catshark | |
| Synonyms | |
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Proscyllium alcocki Misra, 1950 |
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The pygmy ribbontail catshark (Eridacnis radcliffei) is a small type of finback catshark. It belongs to the family called Proscylliidae. You can find this shark in different spots across the western Indo-Pacific Ocean. Its range stretches from Tanzania all the way to the Philippines.
This shark lives near the edges of continental shelves and island shelves. It usually stays deep underwater, between 71 and 766 meters (233 to 2,513 feet). It often lives on or close to muddy ocean bottoms. The pygmy ribbontail catshark is one of the smallest sharks known. It can grow up to 24 centimeters (9.4 inches) long. It has a thin body and a long, ribbon-like tail fin. Its color is dark brown, with black marks on its dorsal fins and dark bands on its tail. This shark mainly eats bony fishes. It also enjoys crustaceans like shrimp, and sometimes squid. Female sharks give birth to 1 or 2 large pups at a time. This shark is not very important for fishing. It is sometimes caught by accident when people are fishing for other things.
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How This Shark Got Its Name
The first pygmy ribbontail catsharks were found a long time ago. This happened during an expedition to the Philippines between 1907 and 1910. The trip was made by the United States Fish Commission Steamer Albatross.
Hugh McCormick Smith was in charge of this expedition. He wrote about this new shark in 1913. He named it after Lewis Radcliffe, who was a naturalist on the trip. Smith also created a new genus (a group of similar species) called Eridacnis for this shark. The first shark used to describe the species was a 23 cm (9.1 in) long adult female. It was caught near Jolo Island in the Sulu Archipelago, Philippines.
Where Does This Shark Live?
The pygmy ribbontail catshark is the most widespread shark in its genus. However, it is found in scattered locations. It has been seen off the coasts of Tanzania, the Gulf of Aden, and the Gulf of Mannar. It also lives in the Bay of Bengal, near the Andaman Islands, Vietnam, and the Philippines.
This shark lives on the ocean bottom. It prefers depths from 71 to 766 meters (233 to 2,513 feet). You can often find it on the outer parts of continental shelves or upper slopes. It commonly lives over muddy areas.
What Does It Look Like?
The pygmy ribbontail catshark has a slender body. Its snout is short and rounded. It has long, oval eyes with small, simple nictitating membranes (a clear eyelid). Each nostril has a short, triangle-shaped flap of skin in front of it.
Its mouth is wide and V-shaped. It does not have grooves at the corners. Inside, there are many rows of small, pointed teeth. These teeth look more like combs towards the sides of its mouth. There are also small bumps, called papillae, on the roof of its mouth. These bumps are also on the edges of its gill arches.
The shark has two dorsal fins, which are about the same size. The first dorsal fin is a little closer to the pectoral fins than to the pelvic fins. The second dorsal fin is located above the anal fin. Its caudal fin (tail fin) is low and very long. It makes up about a quarter or more of the shark's total length. The tail fin does not have a lower lobe.
The shark is a plain dark brown color. It has black marks on its dorsal fins. There are also darker bands on its tail fin. The longest male shark found was 23 cm (9.1 in) long. The longest female was 24 cm (9.4 in) long. A male shark that was 18.6 cm (7.3 in) long weighed 14 grams (0.49 oz). A pregnant female, 24.2 cm (9.5 in) long, weighed 37 grams (1.3 oz).
Life and Habits
Pygmy ribbontail catsharks are said to be very common in some places. This includes areas off southern India and the Philippines. One study in Indian waters looked at what these sharks eat. It found that 55% of their diet was bony fishes. These were mostly lanternfishes, but also bristlemouths and small eels. About 28% of their diet was crustaceans, mainly shrimp. They also ate stomatopods and crab larvae. Another 14% of their food was squid. The rest was other small items, including a bivalve.
Reproduction and Young
These sharks reproduce in a special way called aplacental viviparous. This means the young grow inside the mother. They get their food from a yolk sac until they are ready to be born. Female pygmy ribbontail catsharks can become pregnant when they are about 16.6 cm (6.5 in) long. However, only females longer than 18 cm (7.1 in) have been found with fully developed babies. This suggests that the babies grow a lot during the time they are inside the mother.
One or two pups are born at a time. The newborn sharks are very large compared to their mothers. They measure around 11 cm (4.3 in) long when they are born. Males become ready to reproduce when they are 18 to 19 cm (7.1 to 7.5 in) long. Females might be ready when they are 15 to 16 cm (5.9 to 6.3 in) long. These sizes are similar to other very small sharks. This includes the spined pygmy shark and the dwarf lanternshark. This makes the pygmy ribbontail catshark one of the smallest sharks in the world! It's hard to know for sure which of these species is truly the smallest.
Human Interactions and Conservation
Pygmy ribbontail catsharks are sometimes caught by accident. This happens in bottom trawls off the Philippines. Bottom trawls are nets that are dragged along the ocean floor. However, these sharks are not usually used for anything after they are caught.
The International Union for Conservation of Nature (IUCN) has not yet checked the conservation status of this shark. This means we don't have a clear idea if its population is healthy or if it's at risk.
