The presence of Dolomedes plantarius (Clerck, 1757) (Araneae: Pisauridae) in the Ebro Delta extends its distribution in the Iberian Peninsula southwards

The rare Dolomedes plantarius has been observed in a permanent pond ("ullal") in the Ebro Delta (Catalonia, north-eastern Spain). This is the most meridional record registered in the Iberian Peninsula, and perhaps in western Europe. Thus, the presence of this semiaquatic species may vary our assumptions on its rarity. Such finding evidences the relevance of aquatic environments in general and "ullals" in particular for biodiversity conservation, as well as the importance of considering both the semiaquatic and the terrestrial species inhabiting them.