mesopsammon

mesopsammic +‎ -on

mesopsammon (uncountable)

1. Small species that live in mesopsammic spaces where water is filtered between grains of sand and fine gravel.
   • 1971, Smithsonian contributions to zoology - Issues 72-77, page 18:

     The body, however, is always extremely slender with a diameter of not more than 500 μ, thus enabling the animals to move through the interstitial system without actively replacing the sand grains; all the listed species, therefore, are considered to be mesopsammon forms sensu Broaden (1962)

   • 2003, Italian Habitats: Sand dunes and beaches, →ISBN, page 71:

     The mesopsammon of intertidal environments and the many physical, chemical and mineralogical factors which affect their presence are very complex.

   • 2012, Per Sundberg, ‎R. Gibson, ‎& G. Berg, Recent Advances in Nemertean Biology, →ISBN:

     As is the case with mesopsammic representatives of other major taxa, interstitial nemertines constitute a unique biological grouping recognizable by specializations that are characteristic of mesopsammon (see Swedmark, 1964, for review of the nature of interstitial organisms).