Many different animals eat fish eggs. Fish eggs, also known as fish roe or caviar, are an important food source for aquatic and terrestrial animals. Fish lay eggs in large numbers, so they provide plentiful nutrition for predators. Animals that eat fish eggs include other fish, birds, mammals, amphibians, and invertebrates.
Fish that Eat Fish Eggs
Many species of fish eat the eggs of other fish. This helps control fish populations and provides an easy meal. Some examples of fish that eat eggs include:
Salmon
Salmon are notorious for eating the eggs of other salmon. As Pacific salmon migrate upstream to spawn, they may encounter nests, called redds, built by salmon who spawned earlier. Salmon will dig up these redds and eat the eggs inside. This egg predation helps ensure that only the strongest salmon survive.
Trout
Trout also readily eat the eggs of other fish. Lake trout and brook trout feed on the eggs of minnows, sunfish, and perch. Rainbow trout and brown trout eat the eggs of Pacific salmon when they are available. The protein-rich eggs help trout grow large and fat.
Catfish
Many catfish species are efficient egg predators. Channel catfish, blue catfish, and flathead catfish use their keen sense of smell to find fresh egg clutches. They vacuum up the eggs with their toothless mouths. Freshwater drum, relatives of catfish, also eat fish eggs from lake and river bottoms.
Char
The char family includes Dolly Varden, brook trout, lake trout, and Arctic char. These predatory fish use their sharp teeth to puncture the eggs of other fish. Chars mainly feed on the eggs of groundfish, salmon, herring, and other schooling fish.
Birds that Eat Fish Eggs
Fish eggs provide birds with an excellent source of protein. Many aquatic birds and waterfowl rely on fish eggs during breeding season. Some examples include:
Gulls
Gulls are opportunistic feeders that readily eat fish eggs when available. Herring gulls, ring-billed gulls, and other species scavenge fish eggs from spawning areas in lakes and oceans. The eggs provide gulls with energy for migration and breeding.
Terns
Terns are graceful diving birds that plunge into water to catch fish. They also eat eggs near the water’s surface. Common terns, arctic terns, and Forster’s terns all target dense schools of fish eggs. The eggs supplement their diet of small bait fish.
Loons
Loons migrate to lakes and rivers to build nests and breed. While there, they feast on the eggs of bass, perch, pike, and trout. Loons swallow the small eggs whole, often diving 30 meters underwater to find egg clutches on the bottom. Their sharp beaks allow them to spear and eat eggs.
Cormorants
These large water birds have webbed feet and long necks. They dive deep underwater to reach fish eggs. Double-crested cormorants and great cormorants can eat thousands of fish eggs per day. The nutritious eggs help them regain body mass after winter migration.
Mammals that Eat Fish Eggs
Many marine and semi-aquatic mammals also eat fish eggs when the opportunity arises. Eggs provide mammals with protein, healthy fats, vitamins, and minerals. Some examples include:
Raccoons
Raccoons use their dexterous front paws to feel for fish eggs in shallow water. They grab eggs to eat right away or carry them back to the shore for a meal. Raccoons raid spawning grounds to eat eggs of trout, salmon, shad, and suckers.
Otters
River otters and sea otters feed extensively on fish eggs, which provide nearly half their annual nutrition. They use their sensitive whiskers to detect eggs buried in gravel. Otters then dig up and consume the eggs. Some otters even patrol spawning streams to target migrating fish.
Bears
Bears gobble up fish eggs in large quantities wherever they can find them. Black bears wade into streams and scoop up mouthfuls of trout and salmon eggs. Grizzly bears and brown bears along the coast feast on the eggs of salmon, herring, capelin, and other fish.
Mink
Mink are semi-aquatic mammals that prey on fish and aquatic invertebrates. They regularly eat the roe (eggs) of herring, salmon, shad, smelts, and other fish near the water’s surface. Fish eggs provide mink with the dense nutrition they need.
Amphibians that Eat Fish Eggs
Salamanders and frogs in and around freshwater sources will eat fish eggs when they get the chance. The eggs provide them with protein and nutrients. Examples include:
Giant Salamanders
Giant salamanders of China and Japan prey on fish eggs. Their huge size allows them to gorge on egg clutches from carp, salmon, and trout. Their larvae also vacuum up eggs. Loss of spawning habitat has caused giant salamander numbers to decline.
Bullfrogs
As tadpoles, bullfrogs eat algae and plants. As adult frogs, they become voracious predators. Bullfrogs eat bass, bluegill, and other fish eggs. They wait motionless for egg clutches to drift near, then strike.
Leopard Frogs
Leopard frogs inhabit lakes, rivers, and wetlands across North America. They eat a wide variety of aquatic prey, including insect larvae, crustaceans, worms, and fish eggs. Large numbers of leopard frog tadpoles can decimate fish egg clutches.
Invertebrates that Eat Fish Eggs
A diversity of invertebrates also feed on fish eggs. These small aquatic animals provide an important check on fish populations. Some examples are:
Dragonfly Nymphs
Dragonflies begin life as nymphs in lakes and ponds. Dragonfly nymphs are fearsome aquatic predators armed with a retractable jaw for snatching prey. They consume large numbers of fish eggs, including eggs from sunfish, bass, carp, and perch.
Damselfly Nymphs
Damselflies are close relatives of dragonflies. Their nymphs also hunt fish eggs. Using scoop-like mouthparts, they slurp up eggs from substrate and vegetation. Damselflies help control mosquito and midge larvae populations while feeding on fish eggs.
Crayfish
Freshwater crustaceans called crayfish eat a variety of aquatic plants and animals. Using their claws and legs, they grab and consume fish eggs from the substrates of rivers, lakes, and wetlands. They preferably eat the eggs of sunfish, bass, crappie, and perch.
Leeches
Most leech species feed on the blood of mammals and birds. However, some are predatory and feed on eggs. These leeches use a protrusible jaw to suck out the contents of fish eggs. They target the eggs of catfish, perch, salmon, and other fish.
Conclusion
In summary, fish eggs are a nutritious food source consumed by diverse aquatic and terrestrial animals. Predators like fish, birds, mammals, amphibians, and invertebrates all eat fish eggs for their dense protein, energy, vitamins, and minerals. This predation helps regulate fish populations in lakes, rivers, and oceans. Protecting spawning habitat allows many types of animals to take advantage of this seasonal abundance of fish eggs.
Animal | Examples |
---|---|
Fish | Salmon, trout, catfish, char |
Birds | Gulls, terns, loons, cormorants |
Mammals | Raccoons, otters, bears, mink |
Amphibians | Giant salamanders, bullfrogs, leopard frogs |
Invertebrates | Dragonfly nymphs, damselfly nymphs, crayfish, leeches |