microfaunal

mi·cro·fau·na

M5294400 (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