iStockThe shark’s scientific name semifasciata comes from the Latin words semi ("half") and fasciatus ("banded").
When hundreds of leopard sharks were found dead and dying in California's San Francisco Bay in May 2017, we wanted to learn more about these beautiful fish. Here are 10 interesting facts about Triakis semifasciata. Plus, answers to some of the most common questions divers ask, including how the leopard shark differs from the zebra shark, and whether they're safe to swim with.
1) The leopard shark is a species of houndshark, in the family Triakidae. Found along the Pacific coast of North America from Oregon to Mazatlán, Mexico, Triakis semifasciata is one of the most common sharks in California's coastal waters. Its genus name Triakis comes from the Greek for "three-pointed"—a reference to its distinctive teeth (more on that below).
2) Leopard shark teeth are flat and pavement-like. This design is better for smashing than cutting; they use suction to pluck up prey. Leopard sharks follow the tide onto mudflats to forage for food, retreating just fast enough to prevent being stranded or trapped as the water recedes. They feed on animals that live in the mud, like the fat innkeeper worm, crabs, shrimp, octopuses and fish.
3) Baby leopard sharks, or pups, are born live—not hatched from eggs. They come into shallow water to give birth to live young in spring. Females can produce from seven to 36 pups per litter, each measuring 8 inches (20 centimeters) at birth. This reproductive strategy is called ovoviviparous: embryos develop inside eggs that hatch internally.
4) Leopard sharks are more active at night than during the day, and sometimes are found lying still on the bottom.
5) Adult leopard sharks reach lengths of over 6 feet; though they average less than 5 feet in length. The maximum lifespan of leopard sharks is estimated at 30 years. Found in many aquariums, they have lived up to 20 years in captivity.
Related Reading: Leopard Shark, Zebra Shark or Both?
6) Where can you dive or swim with leopard sharks? La Jolla, California, is the best-known spot in the world. Every year, thousands of leopard sharks migrate to the warm, shallow waters of La Jolla Shores for breeding season. While migrating leopard sharks have been documented traveling hundreds of miles, most leopard sharks are “homebodies” that remain in the same area for much of their lives. Leopard sharks are most common in shallow water. They prefer muddy bay habitats, especially in northern California.
7) Are leopard sharks dangerous? No—they are considered harmless to humans. The leopard shark poses virtually no danger to humans. The International Shark Attack File has a single report of an incident involving a human and a leopard shark, which did not cause any significant injury and involved no bite.
8) Larger sharks such as the great white shark (Carcharodon carcharias) and the broadnose sevengill shark (Notorynchus cepedianus) have been known to prey on small leopard sharks.
Related Reading: Hundreds of Leopard Sharks Dying in San Francisco Bay
9) Leopard shark vs. zebra shark: what's the difference? This question is often raised by divers confusing leopard sharks and zebra sharks, but the two are unrelated. Triakis semifasciata is called a leopard shark in the United States, but commonly called a zebra shark in Australia. Meanwhile, Stegostoma fasciatum is called a zebra shark in the United States but a leopard shark in Australia and much of the Indo-Pacific. The California leopard shark is a houndshark with saddle-like spots on a silver-gray body, found along the Pacific coast of North America. The zebra shark (Stegostoma tigrinum) is a carpet shark found throughout the tropical Indo-Pacific; juveniles have bold zebra-like stripes that change to spots as they mature into adults.
10) California implemented fishery management regulations in 1992 that helped stabilize leopard shark populations. Scientists say hundreds of leopard sharks were found dead in San Francisco Bay in a mass mortality event believed to be caused by meningitis linked to a fungal bloom in stagnant water. Though the IUCN has assessed the leopard shark as Least Concern, local populations can be vulnerable given the species' slow growth, late maturity, and limited migratory range. The 1992 regulations reduced harvesting to sustainable levels—a conservation success story worth noting.
