Science Friday Podcast Recap: This Fish Sucks

In a recent podcast episode of the Science Friday podcast with host Ira Flatow, he and his guest Adam Summers of the University of Washington Friday Harbor laboratory discussed a recent discovery regarding the northern clingfish that may lead to scientific innovations. The northern clingfish lives in the Pacific Ocean along the coasts of North America in the intertidal zones. The fish is about the size of the average human hand, and it initially seems like your average bottom-dweller - perhaps a cross between a catfish and a tadpole. What makes the fish so very unique is that, as the title claims, "this fish sucks". On the bottom of the fish, there is a small disc resembling a suction cup that is the pelvic and pectoral fin of the fish. This suction cup allows the northern clingfish to latch itself onto rocks along the coast and not get carried away by the strong force of the tides that constantly exist in its home. The surface of the rocks it clings onto is not like the bathroom tiles that suction cups stick onto in the average person's house, however. The surface is very rough and covered in slime called biofilm. So how does this fish do it? The suction cup on the northern clingfish is special because it does everything that a normal suction cup does - it pushes out all the air underneath the suction cup creating a vacuum with no air pressure while the atmospheric pressure surrounding it presses it down and allows it to suck on to the surface it is attached to - the secret to the extraordinary power of its suction cup is the hairs around the sucker. The hairs provide friction and stop the sucker from slipping. Does this mean that scientists can use this information to create more powerful suction cups that human can use to, say, walk up walls? Yes and no. These hairs only function when immersed in water, so it could not be used to scale walls with special suction cupped shoes. However, scientists are now developing technology using the information found from the study of the northern clingfish's suction cup that will attach to whales in order to more closely study them.