The coloration of this spider is extremely variable, varying between dark brown, grey and nearly black.
Wadicosa fidelis is the commonest wolf spider (lycosidae sp.) living near water.
It is commonly encountered running about on damp ground close to the waterline and sometimes upon the water surface.
This female carries a large blue eggsac which she drags around until the eggs hatch.

Embalse de Talaván, Extremadura, Spain, 3 May 2012