Some flatfish such as halibut actually have a 'migrating' eye that moves to the upward-facing side of the fish as it ages. Those bottom feeders with upward-pointing mouths, such as stargazers, tend to seize swimming prey. Also, many exhibit what is termed an 'inferior' mouth, which means that the mouth is pointed downwards this is beneficial as their food is often going to be below them in the substrate. The exception may be the flatfish, which are laterally depressed but lie on their sides. In fish, most bottom feeders exhibit a flat ventral region so as to more easily rest their body on the substrate. In darker deep waters, some bottom predators uses aggressive mimicry and bioluminescence to visually lure and ambush prey, as in the case of anglerfish. Others burrow deep into the floor and hunt with most of the body remaining buried, as in the case of oceanic bobbit worms. One common method is the animal using body movements to stir up sand and conceal itself with sediment, a tactic used by many species of flatfish or simply hide inside burrows or around other existing covers, such as many species of octopus and mantis shrimps, before suddenly emerging from cover to catch unsuspecting prey with fast strikes.

Some bottom feeding predators use the floor terrain as cover to ambush their prey. Lastly, some bottom feeders are carnivorous and specialize in either hunting other benthic animals, or scavenging from bodies killed by other predators. Other bottom feeders graze on living aquatic plants and macroalgae, as is the case in some sea urchin species.

In 2014, it was reported that deep sea bottom feeders absorb carbon dioxide by eating creatures such as jellyfish and cephalopods, allowing the greenhouse gas to be retained at the sea floor rather than be released back into the atmosphere. This biotic decomposition and recycling of organic matter is critical for the health of many aquatic environments as it helps maintain various biogeochemical cycles. Bottom feeders may gather detritus manually, as some crab species do or filter microparticles out of the water using suspension feeding. In ocean environments, this downward drift of detritus is known as marine snow. Some bottom feeders are detritivores taking advantage of organic materials that sink down through bodies of water to the bottom. Examples of bottom feeding fish species groups are flatfish ( halibut, flounder, plaice, sole), eels, cod, haddock, bass, grouper, carp, bream ( snapper) and some species of catfish, sharks. Biologists also use specific terms that refer to bottom feeding fish, such as demersal fish, groundfish, benthic fish and benthopelagic fish. However the term benthos includes all aquatic life that lives on or near the bottom, which means it also includes non-animals, such as plants and algae. Biologists often use the terms benthos-particularly for invertebrates such as shellfish, crabs, crayfish, sea anemones, starfish, snails, bristleworms and sea cucumbers-and benthivore or benthivorous, for fish and invertebrates that feed on material from the bottom. This species is Corydoras paleatusĪ bottom feeder is an aquatic animal that feeds on or near the bottom of a body of water. A cory catfish, a commonly kept bottom feeder species in freshwater aquaria.

Saltwater bottom feeder fish