Influences des glaciaires-interglaciaires sur les ichtyofaunes des eaux douces européennes

• Published in: Quaternaire
• Main Author: Le Gall, Olivier
• Format: Article in Journal/Newspaper
• Language: French
• Published: Association française pour l’étude du quaternaire 2013
• Subjects: Pleistocene; Europe; fishes; fresh waters; Palaeoclimatology; eaux douces; poissons; paléoclimats; envir; geo; Anguilla anguilla
• Online Access: https://doi.org/10.4000/quaternaire.5570; http://journals.openedition.org/quaternaire/5570

Continental ichthyofaunas are formed by species who lived strictly in fresh waters (stenohalines) and by species, which can adapt themselves to different salinities (euryhalines) and are generally migratory for the reproduction. These two fish categories are characterized by different mobilities (possibility to colonize new environment), limited for the stenohaline individuals that constitute the great majority of the species concerned by ichthyofaunas studies, they are important for the migrants. The fishes are very dependents on temperature, notably during the reproduction, and on the competence of the aquatic environments. So they should constitute excellent proxies of the environmental variations. In fact the composition of the Pleistocene ichthyofaunas divides Europe in two areas: 1) the North was under the influence of the glaciations: only the cold taxa have survived among the stenohaline, they will only provide information about competence of the aquatic environments (Esox lucius). In this geographic area, the indication of temperature variation will be obtained through the study of the migratory species (Alosa alosa and Anguilla anguilla). 2) in the South, cold and warm species have coexisted and close detailed observations, based on “biozonations”, are in theory possible. Unfortunately, climatic modifications are characterized by limited amplitudes. The come back of thermophilic species in Northern Europe will only happen during the Tardiglacial from “refuge zone” of the Southern Europe (particularly from the Black Sea and its margins). They have probably passed by the Baltic Sea, North Sea and the Channel. Les ichtyofaunes continentales pléistocènes se composent d’espèces strictement d’eaux douces (sténohalines) et d’espèces pouvant s’adapter à des salures différentes (euryhalines) généralement migratrices à l’occasion de leur reproduction. Ces deux catégories de poissons sont caractérisées par des mobilités (possibilité de conquête de milieux) différentes, très limitées chez les sténohalines qui ...