Benthic Organisms Facts Sheet


Benthic organisms, or benthos, live in, on, or near the bottom of aquatic environments.

There are two types:

Epifauna- live on the surface of the bottom

Infauna- burrow into the sediment on the bottom

Divided by size: 

Microbenthos (<100mm) includes bacteria & protests

Meiobenthos (100-500mm) includes small metazoa and larger protists

Macrobenthos (>500mm) includes larger metazoa and megabenthos

          Megabenthos (very lrg.) large crustaceans, mollusks, etc.

Also divided by what they eat:

Herbivores- feeds on plant material

Carnivores/predators- feeds on other benthic organisms

Detritivores- feeds on dead plant and animal material

And how they eat:

Suspension feeders- eats using a mucus-covered appendage that catches particles in water column

Filter feeders- strain particles from the water column

Deposit feeders- ingest sediment and removing the nutrients

Scavengers- feed on dead bodies or remnants of benthic or other organisms found water column

Predators- hunt and catch prey


“Benthic Organisms.” Galveston Bay National Estuary Program (1995). 

Retrieved from the World Wide Web 11 November 2003:


Rumohr, Heye.  “Benthos.” Aqualex Multimedia Consortium (2003)

Retrieved from the World Wide Web 11 November 2003:

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Last Updated 01/26/2010