Fig. 3From: Uncharted biodiversity in the marine benthos: the void of the smallish with description of ten new Platyhelminth taxa from the well-studied North SeaNumber of Platyhelminth species accumulated over the tidal gradient near Sylt island using data until 2015 (broken blue line) and including the current study (solid blue line). The red line gives the linear regression between the upper supratidal and the lower intertidal (solid) and its extrapolation towards the subtidal (dotted)Back to article page