microfaunal

mi·cro·fau·na

 (mī′krō-fô′nə)
n. pl. microfauna or mi·cro·fau·nas
Microscopic or very small organisms, such as protozoans, that live in soil or benthic sediments.

mi′cro·fau′nal adj.

microfaunal

(ˌmaɪkrəʊˈfɔːnəl)
adj
(Microbiology) relating to microfauna