A recent Facebook post/video brought to mind one of my favorite intertidal fish species, the northern clingfish. This fascinating 3-minute video, by a University of WA team, grabbed first place honors in the 2016 Ocean 180 Video Challenge honoring excellence in science communication. The video illustrates how this species is able to adhere to rocks and other substrate in a habitat where rampaging waves and swift currents would otherwise sweep it away.
The northern clingfish, known in scientific circles as Gobiesox meandricus is a species that our monitoring teams have frequently run across when tipping up small boulders on rocky beaches . Like most species of intertidal fish, it’s a little guy with a maximum length of about 6 inches. References set forth its range from the intertidal zone to a depth of 30 feet. It is seen in shades of gray, brown, or dark red with a pattern described as reticulated or chainlike. The clingfish’s flattened head and body form help it wedge its way up underneath rocks. An adhesive disk formed from the pectoral fins on the underside of the body covers about 25% of the surface area of the belly. That is the point of adhesion and I encourage you to check out the prize winning video to dive deeper into just how it works.
The northern clingfish starts life in a single layer of bright yellow to golden brown eggs deposited in clusters on the underside of rocks. The eggs are guarded by the male and once hatched, the larval fish join the plankton. When they reach a length of about 0.4 inch, they settle out of the plankton often onto bull kelp and later moving into the intertidal zone.
As the tide rolls in, clingfish leave their hideout and venture out to feed. Diet varies somewhat with size. Smaller individuals feed on copepods, amphipods, polychaetes, periwinkles, and isopods. Larger ones add limpets, chitons, and hermit and other small crabs to their menu. Larger clingfish employ their adhesive disk to stabilize their body as they pry limpets and chitons off the rocks with chisel-like teeth.
In our nearshore food web, the predatory northern clingfish in turn falls prey to a myriad of species. When submerged, danger lurks from rockfish and diving cormorants but other threats arise when the tide recedes. Hungry mink, raccoons, gulls, and even gopher and garter snakes then descend onto the beach to browse intertidal nooks and crannies in search of a plump clingfish.
Congratulations to the folks from UW who did a superb job of illustrating how the northern clingfish is so well adapted to adhering to rocks and other surfaces. We enthusiastically give their video two thumbs up! See it for yourself at the UW news website..