Definition of meiofauna in US English:



  • Minute interstitial animals living in soil and aquatic sediments.

    • ‘In other words, at some point an ancestral deuterostome became really small, probably as a member of the meiofauna, and lost a number of complicated organ systems as a result.’
    • ‘The meiofauna, as the tiny invertebrate animals are called, are equipped with all sorts of odd appendages and body shapes that are well adapted to this unique environment.’
    • ‘The loriciferans seem to be one of the most abundant groups of meiofauna in the deep-sea, but also occur in mud on shallower water, and they may be one of the dominant meiofauna groups.’
    • ‘The Kinorhyncha are microscopic, bilaterally symmetrical, exclusively free-living, benthic, marine animals and ecologically part of the meiofauna.’
    • ‘The scientists found on the ocean floor miniscule meiofauna, single-celled creatures less than half a millimeter long, the most successful and numerous animal in the southern sea.’


1960s: from Greek meiōn ‘less or smaller’ + fauna.