• synonyms


noun, plural in·fau·nas, in·fau·nae [in-faw-nee] /ˈɪnˌfɔ ni/. Ecology.
  1. the aggregate of animals that burrow into and live in the bottom deposits of an ocean, river, or lake.
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Compare epifauna.

Origin of infauna

First recorded in 1910–15; in-1 + fauna
Related formsin·fau·nal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

infaunal in Science


  1. Benthic animals that live in the substrate of a body of water, especially in a soft sea bottom. Infauna usually construct tubes or burrows and are commonly found in deeper and subtidal waters. Clams, tubeworms, and burrowing crabs are infaunal animals. Compare epifauna.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.