Abstract:
The halophilous habitats, commonly found in the Danube Delta Biosphere Reserve, are restrictive habitats for most
edaphic microarthropods; soil with high salt content, excess moisture and deficient aeration are the main limiting
environmental factors. The present study aims to investigate, both from qualitative and quantitative points of view, the
oribatid mite communities in these habitats of DDBR, less approached in previous ecological research. Following the
field research, representative sampling sites were selected, located in the western DDBR, north of the Razim-Sinoe
lagoon complex, between Murighiol and Enisala.
In terms of fauna, the small number of taxa was noticed (14 species, belonging to 12 genera and 9 families); poronotic
oribatid mites are dominant both as number of species and individuals. Humerobates rostrolamellatus Grandjean, 1936,
and also the genus Humerobates Sellnick, 1928 and the family Humerobatidae Grandjean, 1971 are recorded now for
the first time in the Romanian fauna. Oribatid communities are simply structured, with a small number of species and
low specific diversity, indicating a poor stability. In most of the investigated sites Oribatula (Zygoribatula) undulata
Berlese, 1916 is the over-dominant species, holding 46-94% of all individuals. In addition, the frequency and relative
abundance of the immature stages highlights the full adaptation of this species and its bio-indicator quality in relation to
saline soils.
