Bottom feeder fish are those that eat from the bottom third of the water column, but not necessarily those that spend all their time at the bottom of the water column. Some fish species, like catfish, feed from the bottom, but also spend time at different levels. Bottom feeder fish can be found in natural freshwater settings and in saltwater natural settings.
Additionally, small fish species have long been used in freshwater aquariums and saltwater aquariums. Bottom dwellers who live in aquariums are valuable in keeping the tank clean. Not only do bottom feeders eat fish poop, but they eat algae from the sides and bottom of the tank. In a freshwater aquarium, algae eaters are essential to maintaining a healthy environment. Not only do they clean the bottom of the tank, but they clean up uneaten food that might affect pH balance and water quality.
Most bottom feeder fish would rather eat food leftovers or algae blooms than fish feed. That is how they earned the nickname algae eater. Most people think of the bristlenose pleco, or vacuum cleaner fish, when looking for a cleaner fish, but there are many other fish species that help maintain a healthy aquatic environment in a freshwater aquarium. Siamese algae eaters, otocinclus catfish, and cory catfish are great bottom feeders for your fish tank and add color and life to your aquarium hobby tank.
There are other fish who are bottom feeders that are also attractive and beautiful. The zebra loach has attractive patterning and feeds on algae and debris. Cherry shrimp are bright and colorful and add a burst of color to your tank. Rosy barbs are very peaceful fish that travel in small schools (6-8 in a 40 gallon tank with other fish) and get along well with most tank mates.
If you have a larger saltwater tank, you can even add bottom feeder fish like rays and eels to your underwater community. The size of your fish tank will determine what species of fish you can keep.
In zoos and retail store freshwater aquariums, it is not unusual to find catfish, crappie, bluegill, and bass cohabitating in a community tank. While your home tank may only be a 20 or 40 gallon tank, you can still find many species of bottom feeder fish that will get along with your other species. If you need help finding peaceful community fish to add to your freshwater fish tanks, ask the experts at your aquarium trade store. They will know which bottom feeder fish are compatible with other fish in a community tank.
Naturally occurring bottom dwelling fish typically help keep lake and river waters clean by eating debris and the remains of other fish. They also improve water quality by constantly stirring up bottom sediment and eating aquatic organisms and some types of algae. As you study these, you will discover that many are related to the feeder species sold in the aquarium trade.
Freshwater bottom feeding fish (ponds, lakes and rivers)
Catfish are probably the most well known of all the bottom feeder fish. They are a popular fish for anglers who want to eat their catch. There are many species of catfish in freshwater locations all over the world. Some species, like the tiger shovelnose catfish, are harvested when they are young and sold for use in freshwater tanks. The same is true of corydoras catfish and synodontis catfish, both of which are native to the waters of South America.
When anglers start talking about catfish, though, the conversation usually revolves around blue cats, channel catfish, bullheads, or flathead. Even though all these catfish are slightly different, they all share the same characteristic of being bottom feeder fish. They feed on dead fish, algae, garbage, and anything else they can find.
The carp species is a large grouping and over 2000 types of fish fit into the classification Cyprinids, to which carp belong. Some types of carp are caught very small and sold as aquarium fish that clean the bottom of the tank. Carp are omnivorous fish. They will not only eat algae, insect larvae, and debris like most bottom dwelling fish, they also eat live foods including smaller fish, brine shrimp, and insects.
Some anglers enjoy a meal of carp, but others think it is too greasy. Much of that depends on the type of diet the fish consumes. Catching carp can be a challenge, as they can grow very large in the wild.
While some sturgeon, like the shovelnose sturgeon and the white sturgeon can be found in freshwater lakes, the Atlantic sturgeon is anadromous. This bottom feeder fish is actually born in fresh water, but migrates into salt water as it grows, then returns to fresh water to spawn and die.
Once endangered, because of recreational and commercial fishermen, the sturgeon is now being bred and stocked into many lakes and rivers as recovery efforts continue. The sturgeon is one of the oldest living fish of record. Fossils have been found that are thousands of years old, and many feel the sturgeon may have been alive when dinosaurs roamed the earth.
Sturgeon are not picky in what they eat. In captivity, these fish will swallow pellet foods just a easily as smaller fish. In the wild, sturgeon prefer meaty foods like crabs, clams, and bottom dwelling shrimp.
Among anglers, sturgeon is a highly desired fish because it puts up a tremendous fight when hooked. Larger fish are used for meat, and sturgeon is a mild, sweet-tasting fish with delicate and flaky meat. It can be prepared a number of ways and still taste great.
Ah, the bass. A favorite of anglers, bass are elusive fish preferring to remain in hiding places and let the food come to them. Definitely opportunistic feeders, bass will eat whatever swims by. They will also feed on phytoplankton and zooplankton in algae-filled ponds, mussels and freshwater clams, and debris like fish remains. Among bottom feeders, bass are like the garbage men of the lake.
Anglers love bass for the thrill of the catch, the bragging rights, and the taste. Depending on what they eat, bass can taste sweet or muddy. Like many bottom feeder fish, their survival is linked to their diet. Some lakes and rivers provide a balanced diet and some do not.
The lake trout, or Arctic char, is not actually a trout at all. This fish is more closely related to salmon than trout. Lake trout are bottom feeder fish. They prefer to eat feeder fish and will often wait for a school to swim by, then gulp down large quantities of small fish. They have also been known to eat crabs, shrimp, and mussels. Juvenile lake trout can be considered more of an algae eater. They tend to rely on insect and frog eggs, plankton, and algae. Lake trout are large fish and anglers like to reel in these freshwater bottom feeders. They are desired mainly for sport fishing though because the meat is fatty and oily and can have a strong fishy smell and taste.
Saltwater bottom feeders
Bottom feeder fish can also live in saltwater. Because of the immense size of the oceans, the term bottom feeders is relative to the lower third of the water column, which could be thousands of feet deep. Perhaps a better to classify these fish would be to call them bottom dwellers. While they do not spend all of their time on the floor of the ocean, a good part of their time is spent near the bottom.
Halibut are among the largest flatfish in the world. These bottom feeding fish are genetically engineered to eat from the floor of the ocean. Pancake shaped, with both eyes on the top of the body and the mouth on the underside, halibut suck different forms of aquatic animal and plant life from the sand. There are two different species of giant halibut, the Atlantic and the Pacific, so named because of the ocean in which they live.
One of the most popular game fish among saltwater anglers, the flounder is an exclusively bottom-feeding fish. This fish, like the halibut, is flat and pancake-shaped. Both eyes are found on the upper side of the fish, which ranges in color from light brown to dark brown with stripes. The mouth of the fish is on its light colored underside. The sands of the ocean floor provide natural hiding places for the flounder. Flounder feed on smaller fish spawn, crabs, and shrimp.
Atlantic cod are bottom feeders who prefer cold water. While not a flatfish, cod eat the same foods as the halibut and flounder, primarily feeding on feeder fish, crustaceans, and shrimp. Cod is commercially harvested and used in frozen foods. This white, flaky fish is excellent to eat.
Snapper is a popular game fish found in warm, tropical waters like those found in the Gulf of Mexico and the waters surrounding South America. While they do not live on the bottom, we can classify snapper as bottom feeders because they eat fish and organisms that live on the bottom. Popular foods for snapper include smaller fish, octopus, and squid. Because they have rows of sharp teeth, snapper can also eat crabs, lobster, and oysters.
Grouper are giant fish with huge mouths that eat large quantities in one bite. They also have the unique ability to suck up sand, and any creatures in the sand, then expel the sand through their gills. This allows them to eat many organisms that bury in the ocean floor, including smaller fish, crabs, lobster, octopus, turtles, and mollusks.
Eels are unique animals that look like half fish and half snake. Their long, flexible bodies allow them to between rocks or inside coral formations. They prefer the darkest parts of the ocean and will feed at night whenever possible. These nocturnal fish eat smaller fish, but will sometimes grab a small crab or squid. Eel have sharp teeth that let them grab and hold their prey.
There are hundreds of species of rays in the oceans. Some are huge and aggressive. Others are small and peaceful fish that just want to survive. All rays have similar body characteristics. They have a long, thin body with two wing-shaped protrusions on either side that allow them to swim and change direction quickly. Rays have eyes on the front of their head, but they don’t use their eyes for sight. Instead, they rely on sensors built into their body. The mouth of a ray is on its underside and is full of sharp teeth. Rays feed on crabs, shrimp, clams, oysters and fish spawn. While rays are beautiful creatures, they are also very dangerous due to the sharp barb on their tail.
Are Bottom Feeding Fish Safe to Eat?
Some people think bottom feeder fish are dangerous to eat because they consume dead, decaying things from the dirty bottom of the lake or ocean. This is not the case. Bottom feeder fish eat shellfish, algae, and other fish, which are some of the same things humans eat. Because they consume all of the creature they are eating, all of the nutrients are absorbed by the bottom feeder fish.
Among freshwater bottom feeders, catfish are considered to be the nastiest of the fish, but in truth, catfish is remarkably healthy to eat. It is a clean, lean protein full of B12, healthy Omega 3 fatty acids, and many other nutrients. The only thing that makes catfish unhealthy to eat is deep frying it with breading and salt, but it sure is delicious that way.
Halibut, a bottom feeder fish that lives in the ocean is recommended by physicians as a regular source of protein that should be consumed once a week. Not only does this fish contain protein, vitamin B and Omega 3 acids, but it is high in magnesium, selenium, and potassium. All these nutrients are essential to heart and bone health. Additionally, researchers have studied the effects of halibut consumption and proven that it helps reduce breast cancer risk, dementia, and heart disease.
Like any food, too much of a good thing might be harmful. While some scientists make claims of high levels of mercury that can be harmful, it would take excessive consumption of high mercury fish like king mackerel or swordfish to ingest dangerous levels of mercury. All fish, and many other foods we eat, contain small amounts of mercury. Eaten in reasonable portions, mercury is not dangerous to humans.
Final thoughts about bottom feeder fish
Bottom feeder fish or bottom dwellers are those fish that tend to eat from the bottom of the body of water, whether that is the bottom of a lake or ocean, or the bottom of the tank. These bottom feeders help create a healthy environment for all the other fish. Not only do they clean the environment of debris and algae, but bottom feeder fish are among the most low maintenance fish in an aquarium or in nature. They take care of uneaten food, bothersome algae blooms, and rotting debris.
In saltwater, the best bottom feeder fish are the best eating fish. Halibut and flounder are both highly prized for their firm, white meat that holds up well in many cooking techniques. Cod is the most used fish in frozen foods and chain restaurants. Bottom feeding fish are valuable creatures.