Leopard shark facts for kids
Quick facts for kids Leopard shark |
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| A leopard shark and two blacksmith damselfish in Birch Aquarium | |
| Conservation status | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Order: | Carcharhiniformes |
| Family: | Triakidae |
| Genus: | Triakis |
| Species: |
T. semifasciata
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| Binomial name | |
| Triakis semifasciata Girard, 1855
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| Range of the leopard shark | |
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| Synonyms | |
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Mustelus felis Ayres, 1854 |
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The leopard shark (Triakis semifasciata) is a cool type of houndshark. You can find it along the Pacific coast of North America, from Oregon in the U.S. all the way down to Mazatlán in Mexico. These sharks are usually about 1.2 to 1.5 meters (4 to 5 feet) long. They have a slim body and are easy to spot because of their amazing pattern. They have black, saddle-like markings and big spots on their back, which is how they got their name!
You'll often see large groups of leopard sharks swimming in bays and estuaries. They like sandy or muddy areas, or places with rocks near kelp beds and reefs. They usually stay close to the coast, in water less than 4 meters (13 feet) deep.
Leopard sharks are active predators. They often follow the tide onto muddy flats to hunt for food. Their favorite meals include clams, spoon worms, crabs, shrimp, small bony fish, and fish eggs. Most leopard sharks prefer to stay in one area. They don't travel far, which means different groups of sharks in different places have become a bit unique over time.
Female leopard sharks give birth to live young. The babies grow inside the mother and get their food from a yolk sac. From March to June, a female can have up to 37 pups after being pregnant for 10 to 12 months. These sharks grow slowly and take many years to become adults.
Leopard sharks are not dangerous to humans. People catch them for food and for aquariums. Most of this fishing happens off the coast of California. In the 1980s, there were fewer sharks, but new rules in the 1990s helped their numbers grow back. The International Union for Conservation of Nature says the leopard shark is a species of "Least Concern". This means they are not currently endangered. However, it's important to fish them carefully because they grow slowly and don't move around much.
Contents
Understanding Leopard Shark Names
Every animal has a scientific name that helps scientists around the world know exactly which species they are talking about. For the leopard shark, its scientific name is Triakis semifasciata. This name was given by a French biologist named Charles Frédéric Girard in 1855.
The name semifasciata comes from Latin words. "Semi" means "half" and "fasciatus" means "banded." This describes the shark's cool pattern of saddle-like markings on its back. Sometimes, in older books, you might see this shark called a "tiger shark" or "catshark" by mistake.
Scientists also study how different animals are related to each other. This is called phylogenetics. Studies have shown that the leopard shark is part of a group called Triakis. It's related to other sharks like the banded houndshark.
Where Leopard Sharks Live and Their Homes
Leopard sharks live in the northeastern Pacific Ocean. You can find them from the cooler waters of Coos Bay, Oregon, all the way to the warmer waters of Mazatlán, Mexico. This includes the Gulf of California.
They love to hang out in muddy or sandy areas inside calm bays and estuaries. You might also see them near kelp forests, rocky reefs, or along the open coast. Sometimes, many sharks gather near warm water coming from power plants. Leopard sharks usually swim close to the ocean floor. They are most common in shallow water, from the intertidal zone (where the tide goes in and out) down to about 4 meters (13 feet) deep. But they can sometimes be found as deep as 91 meters (300 feet)!
In colder areas, many leopard sharks leave their coastal homes in winter. They come back in early spring when the water gets warmer. For example, in Tomales Bay, California, they leave when the water temperature drops below 10–12°C (50–54°F). One tagged shark even swam about 140 kilometers (87 miles) south.
Most leopard sharks stay in one small area for most of their lives. They don't travel very far. Because of this, sharks in different areas have developed small differences in their gene pools. Scientists have found seven different groups of leopard sharks along the California coast.
What Does a Leopard Shark Look Like?
Leopard sharks have a strong, sleek body with a short, rounded snout. They have special flaps of skin in front of their nostrils. Their eyes are big and oval, and they even have a protective third eyelid called a nictitating membrane. Their mouth curves strongly, and they have grooves at the corners.
These sharks have many rows of teeth! There are 41 to 55 rows in the upper jaw and 34 to 45 in the lower jaw. Each tooth has a smooth, pointed center with one or two smaller points on the sides. These teeth are flat and fit together like a pavement, which helps them grab their food.
The leopard shark has two large dorsal fins on its back. The first one is about halfway down its body. Its pectoral fins (on the sides) are wide and shaped like triangles. Its tail fin, called the caudal fin, has a strong upper part.
Their color pattern is very special and gives them their name. They have bold black "saddles" (like markings on a horse's back) and big black spots. These patterns are on a silvery or bronzy gray background. Younger sharks have darker spots, while older sharks often have more spots with lighter centers. Their belly is plain and whitish.
Most leopard sharks are about 1.2 to 1.5 meters (4 to 5 feet) long. Males can grow up to 1.5 meters (5 feet), and females can reach 1.8 meters (6 feet). The longest one ever recorded was an amazing 2.1 meters (7 feet) long! The heaviest leopard shark known weighed 18.4 kilograms (40.5 pounds).
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The leopard shark's unique pattern gives it its name.
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Leopard shark jaws.
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Lower teeth.
Leopard Shark Behavior and Environment
Leopard sharks are active swimmers. They move with a strong, wavy motion and are often seen cruising near the ocean's edge. They are more active at night than during the day. Sometimes, they even lie still on the bottom. In places like Tomales Bay, leopard sharks follow the tide onto muddy flats to find food. They retreat just fast enough to avoid getting stuck when the water goes out.
From the time they are born, leopard sharks form large schools. These groups are usually made up of sharks of similar age and gender. They might even swim with other types of sharks, like grey or brown smoothhounds. These schools seem to move around a lot, appearing suddenly in an area for a few hours before disappearing.
During summer days, many adult female sharks gather in shallow bays and estuaries. They spread out at night. These females look for the warmest patches of water. Scientists think they do this to help themselves and their growing babies get bigger faster.
Leopard sharks have special red blood cells that help them use oxygen very well. This might be because they often hunt in places like estuaries where oxygen levels can be lower. Their eyes don't have many color-sensing cells, probably because they live in murky water.
Smaller leopard sharks can become food for bigger sharks. These include the great white shark and the broadnose sevengill shark. Once, a sevengill shark was seen surprising a leopard shark on a muddy flat!
What Do Leopard Sharks Eat?
Leopard sharks eat small animals that live on the ocean floor or near the shore. Their main foods are crabs, shrimp, small bony fish (like anchovies, herring, and gobies), fish eggs, clams, and a type of worm called the "fat innkeeper worm." They are opportunistic hunters, meaning they will eat whatever they can find. They have also been known to eat ghost shrimp, other worms, and even the young of other sharks and rays. Sometimes, they accidentally swallow eelgrass or algae.
Leopard sharks catch their food by quickly opening their mouths to create a suction force. At the same time, they push their jaws forward to grab the prey with their teeth. Like other sharks, their teeth are always being replaced. It takes about 9 to 12 days for a new tooth to move into place.
Scientists have found clam siphons in shark stomachs. This means the sharks grab the siphons before the clams can pull them back, breaking them off with a strong movement of their bodies. Sometimes, they even pull the whole clam out of its shell! They also suck whole innkeeper worms out of their burrows without biting them. Leopard sharks are also known to use their nose to dig for prey hidden underground.
What a leopard shark eats can depend on where it lives, the time of year, and its age. For example, in Elkhorn Slough, they eat crabs and innkeeper worms in winter and spring. They eat fish eggs from winter to early summer, bony fish in summer, and clams in fall. Young sharks mostly eat crabs. As they get bigger (around 70–80 cm or 2.3–2.6 feet long), they start eating clam siphons, fish eggs, and innkeeper worms. The largest sharks eat the most fish.
Leopard Shark Life Cycle and Reproduction
Leopard sharks give birth to live young. The baby sharks grow inside their mother, getting all their food from a yolk sac until they are born. In northern areas, females use bays and calm waters as safe places for their babies. In southern areas, they give birth in more open waters. Some known places where they have their babies in California include Humboldt Bay, San Francisco Bay, and San Diego Bay.
Females have 1 to 37 pups each year between March and July (most often in April or May). Larger females tend to have more pups. In some bays, females drop their pups in beds of eelgrass, which provides both shelter and food. In other places, they give birth in very shallow water, sometimes so shallow that their backs are exposed! The pups then stay in even shallower water, less than 30 centimeters (1 foot) deep.
Mating happens in early summer after the pups are born. Scientists once saw nine sharks mating off La Jolla in 2004, in shallow water close to shore.
Newborn leopard sharks are about 20 centimeters (8 inches) long. They grow slowly after their first few years. Male sharks grow about 2.0 cm (0.8 inches) per year. They become adults when they are 7 to 13 years old and 0.7 to 1.2 meters (2.3 to 3.9 feet) long. Females grow about 2.3 cm (0.9 inches) per year. They become adults when they are 10 to 15 years old and 1.1 to 1.3 meters (3.6 to 4.3 feet) long. Some sharks grow very slowly; one shark only grew 4 cm (1.6 inches) in 12 years! Leopard sharks can live for at least 30 years.
Leopard Sharks and People
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Leopard sharks are usually shy and swim away quickly. They are almost never dangerous to humans. There was only one report in 1955 of a leopard shark bothering a diver with a nosebleed, but no one was hurt.
People catch leopard sharks for food using nets and long lines. Recreational anglers and spearfishers also catch them. Sometimes, they are caught by accident in fishing nets meant for other fish. Their meat is considered good to eat and is sold fresh or frozen. However, leopard sharks that live near cities can sometimes have harmful substances like mercury and pesticides in their bodies. The California Department of Fish and Wildlife advises against eating them too often.
Leopard sharks are also popular in aquariums because they look nice and are hardy. In the late 1980s and early 1990s, many newborn pups were caught for the aquarium trade. They can live for over 20 years in captivity.
Most leopard shark fishing happens off the coast of California. Commercial fishing peaked in 1983, but new rules helped reduce it. In recent years, more sharks have been caught by sport fishers than by commercial fishers.
The International Union for Conservation of Nature (IUCN) says the leopard shark is of "Least Concern". This means they are not currently endangered. However, their numbers can easily drop in local areas because they grow slowly and don't move around much. In 1992, California put rules in place for recreational fishing, like a minimum size limit of 91 cm (36 inches) and a limit of three fish per person. These rules helped protect the sharks. In 1993, a minimum size limit of 46 cm (18 inches) was also set for commercial fishing, including for the aquarium trade. These rules have helped the leopard shark population in California grow by 3–6% each year, showing that careful fishing can be sustainable.
See also
In Spanish: Tiburón leopardo para niños
