Abstract:
THE BIOGEOGRAPHICAL DISTRIBUTION OF INVERTEBRATE ANIMALS IN FRENCH KARSTS (FIRST PART: THE AQUATIC FAUNA) - This text analyses the bibliographic data in order to draw up a schematic representation of the biogeographical distribution of Invertebrate animals found in French karsts up to 1985. The animal population of these karsts is very varied, especially in the South of France. For many groups, there are obvious links with geological history and paleo-ecology. This text first lists the aquatic groups (from Porifera to Crustacea; the latter is the most varied and numerous in karstic water). It puts forward possible solutions to the problems posed by the ways followed by the ancestors of present-day groups, either of superficial fresh-water origin, or of marine origin during the Tertiary, and whose areas were later modified by the impact of Quaternary glaciations. For the terrestrial groups (cf. Karstologia n° 11), subterranean penetration followed different pathways, among which the Superficial Hypogean Compartment (MSS = Milieu Souterrain Superficiel) plays an obvious role; this shows that many troglobites are not limited, in the underground environment, to just caves and the karst. The Arthropods, and among them the Insects, are of course the most varied and the best known. Their biogeographical distribution reflects the problems of speciation, ecology and endemism, which are discussed in the text.