These Dead Fish Really Suck: Adhesion Performance of the Northern Clingfish

Abstract

The ray-finned fish family Gobiesocidae includes over 100 species of fish that are commonly known as clingfish (Fishbase). These aptly named clingfish posses modified pelvic fins that are fused into a biological suction cup, allowing the fish to adhere to surfaces in their environments. The northern clingfish, Gobiesox maeandricus, is a common inhabitant of the rocky intertidal shores along the Pacific Northwest coast of North America. The northern clingfish can reach sizes up to 16cm but are much more common around 8-10cm (Fishbase). These clingfish use their suction discs to adhere to rocks in their intertidal home, providing a way to remain stationary and stable in the turbulent waters close to shore. Although intertidal rocks differ greatly in surface roughness, we have observed that the northern clingfish does not appear to be limited to only smooth rocks. While manufactured suction cups function only on smooth surfaces, clingfish appear able to stick on the myriad types of surfaces present in the intertidal. This study seeks to compare how well clingfish are able to adhere to surfaces of different roughness.