Piscivore

A piscivore (/ˈpɪsɪvɔːr/) is a carnivorous animal that mostly eats fish. Many animals, both in water and on land, eat fish as a big part of their food. Fish were an important food source for early tetrapod evolution, starting with water-bound amphibians during the Devonian period. Later, animals that lived more on land, like reptiles and synapsids, began to eat plants too.

Almost all predatory fish, such as most sharks, tuna, billfishes, and pikes, are piscivores because they need to eat fish to survive. Some other animals, like whales, sea lions, and crocodilians, also eat fish but will eat other things too, like invertebrates, marine mammals, and even land animals. There are animals such as the bulldog bat and gharial that depend only on fish for food.

Even animals you might not expect, like grizzly bears, jaguars, wolves, snakes, turtles, and sea gulls, will eat fish when they can. Humans can live mostly on fish, and even some domesticated pets like dogs and cats can have fish as a big part of their diet.

Etymology

The word piscivore comes from Latin words. Piscis means "fish" and vorō means "to devour." This is like the Greek word ichthyophage, which also means "fish eater."

Discussion

Piscivores are animals that eat fish. They can change nature in different ways. For example, adding cutthroat trout to a lake can change what bats eat. This is because bats eat insects that come from the water where the trout live. In another case, removing lionfish helps keep coral reefs healthy. Counting piscivores can also show how well the reefs are doing.

Some animals start eating fish early in life. These are called primary piscivores. Others begin eating fish later. These are called secondary piscivores. Scientists think this change helps animals use energy better as they grow.

Examples of extant piscivores

Some animals eat mainly fish.

Arachnids

• Fishing spider

Birds

• Bald eagle
• Merganser
• Osprey
• Penguin

Fish

• African tigerfish
• Alligator gar
• Arapaima
• Barracuda
• Bluefish
• Giant trevally
• Kidako moray
• Lemon shark
• Lionfish
• Piranha
• Silver arowana

Mammals

• Amazon river dolphin
• American mink
• Aquatic genet
• Bottlenose dolphin
• Bulldog bat
• Eurasian otter
• Fish-eating bat
• Fishing cat
• Flat-headed cat
• Fur seal
• Giant otter
• Harbor seal
• North American river otter
• Orca
• Otter shrew
• Sea lion
• Tiger

Reptiles

• Asian water monitor
• Gharial
• Green anaconda
• Komodo dragon
• Yellow anaconda
• Yellow-bellied sea snake

Extinct and prehistoric piscivores

Many ancient animals likely ate fish, based on their body shape or where they lived. Some scientists found fish inside their fossils. This list includes fish-eaters and other predators that ate fish.

Fish

• Diplomystus (a small relative of the herring, fossils show these fish tried to eat others, sometimes even their own kind)
• Thyrsocles (a fossil was found with fish in its stomach)
• Xiphactinus (a big fish found with another fish inside it)

Reptiles

• Baryonyx (a predator with a crocodile-like head, with fish remains found where its stomach would be)

• Elasmosaurus (its long neck and special teeth helped it catch fish)

• Laganosuchus (its flat head suggests it waited for fish to swim close)

• Ornithocheirus (likely ate fish based on its jaws and teeth)

• Pteranodon (some have fish remains in their beaks)

• Spinosaurus (a relative of Baryonyx, it likely ate fish because it lived where large fish were found)

• Titanoboa (its skull and body suggest it ate mainly fish)