In warm, shallow waters around the world, the tiger shark is one of the top predators of tropical and temperate coastal ecosystems. These large, lightly striped sharks are notorious for eating just about anything they come across. Potential encounters with humans in coastal waters are worthy of precaution, but shark attacks are rare. As an _____1_____ predator, the role of the tiger shark in coastal ecosystems is important. But they have declined in places where they are either intentionally or accidentally overfished. Marine biologists are working to ensure a better future for them before it’s too late.

Discovery and Classification

Tiger sharks are known from the fossil record as far back as 56 million years ago. In 2021, new fossil discoveries revealed that the current and only living species of tiger shark (scientific name Galeocerdo cuvier) has been around for at least ____2____ million years. Millions of years ago there were at least five other species that were closely related to today’s tiger shark, but all have gone extinct. We’re left with one species in the formerly diverse Galeocerdo group. 

In modern science, the tiger shark was first described by French explorers Francois Peron and Charles Lesueur in 1822. Taxonomists who study the relationships between species place the tiger shark in the Carcharhiniformes order of sharks. This order of sharks is characterized by a _____3_____ that covers their eyes to improve vision underwater, two dorsal fins, an anal fin and five gill slits. Within this diverse group of 270 species, the tiger sharks make up the Carcharhinidae family. The Carcharhinidae are known as _____4____ sharks, a moniker of French origin that alludes to their superior hunting abilities. As biologists have learned more about the physical and genetic attributes of the species, its placement in the tree of life has changed a few times. 

Today, the taxonomists who study the classification of life place The tiger shark is the largest and most fierce hunter in this family. The bull shark, lemon shark and blue shark are close relatives of the tiger shark.

Large and Adapted to Hunt

Adult tiger sharks are 10 to 14 feet in length and weigh between 850 and 1400 pounds. At birth, they are only one foot in length but quickly grow to adulthood in _____5_____ years. Females are larger than males. The largest female tiger shark on record was a whopping ____6_____ feet in length. Only the great white, whale and basking sharks are larger. 

Tiger shark teeth are very sharp and _____7_____ like a steak knife, perfect for shredding meat. The sharpest tips point sideways on the tooth, an easy identifier of tiger sharks. Like other sharks, the teeth are shed and replaced. 

The _____8_____ helps the tiger shark maneuver through water with precision. The _____9_____ acts like a pivot, which allows the shark to turn on a dime. The skin is a bluish-_____10_____ up top and a lighter colored underbelly. When viewed from above, the shark blends in with ocean water, leaving prey clueless of the approaching predator. They have specialized cells on their snout that detect _____11______ from approaching prey. The lateral line that spans the sides of the shark detects vibrations in the water. Tiger sharks are uniquely adapted as apex predators of the ocean.

At night, tiger sharks feed in shallow waters near shore. They move to deeper waters during the day. Adult sharks hunt for just about any meal they can find. Common prey include dolphins, _____12_____, seals, seabirds and turtles. Research has found that in areas where sea turtles are common, they are a preferred meal for tiger sharks. Although they are primarily fierce predators, tiger sharks won’t pass up a meal if they come across a dead animal such as a whale. They _____13______ with great white sharks when possible. It saves energy versus actively hunting.

Tiger sharks only have two major predators: humans and _____14_____. Also known as killer whales, they are larger than the sharks and are known as very capable predators around the world’s oceans. 

Tiger Shark Conservation

The International Union for the Conservation of Nature considers the tiger shark to be near-threatened due to overhunting by humans for fins, liver and shark meat. When purchased, shark meat has a very high chance of being sourced unsustainably. Marine biologists are teaming up with ____15_____ and international governments to find a way to protect tiger sharks. In some coastal seas with high intensity fishing, the populations of tiger sharks have dropped by 70%. These predators at the top of the food chain are not invincible, so it’s important that we protect and respect them in their serene ocean homes.