Bottom feeder

[3] This biotic decomposition and recycling of organic matter is critical for the health of many aquatic environments as it helps maintain various biogeochemical cycles.

[4] 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;[4] 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.

[9] In darker deep waters, some bottom predators uses aggressive mimicry and bioluminescence to visually lure and ambush prey, as in the case of anglerfish.

Generally, they are only useful for consuming the extra (fresh) food left by overfed or clumsy livestock; the added biomass of additional organisms means that the aquarium will likely be more dirty.

[11] Some specialized bottom feeders are more specifically sold as "algae eaters" to increase the amount of free oxygen and aesthetic appeal of a tank.