The aquatic insects of a standard small plain river in NE France, with emphasis on remarkable species.

A five-year macroinvertebrate study was conducted on a 55 km river (le Rupt-de-Mad, Lorraine region, north-eastern France), a standard for the region. A list of 300 species was drawn up, and remarkable species were listed for some better known orders: Ephemeroptera, Plecoptera, Trichoptera and Odonata. Some faunistic results are emphasised: about 42% of the identified species were more or less ubiquitous, 26% were meso- to polysaprobic species of potamon, present only in the main course of the river, while 31% were rather stenoecious species restricted to certain tributaries. Fifty-one remarkable species were listed, taking into account their regional status, according to IUCN categories: more than three quarters were hosted in the small tributaries, and 55% found exclusively in these latter (versus 23.5% only present in the main course of the river). Calcareous lotic tributaries were hosting particularly original communities with many remarkable species. Ephemeroptera, Plecoptera and Trichoptera were pertinent groups to assess the global faunistic interest of lotic habitats, but lentic habitats are probably better evaluated using other groups, e.g. Odonata and Coleoptera; the latter unfortunately poorly known from an ecological point of view. [ABSTRACT FROM PUBLISHER]