Harsh environments with strong waves and fast-moving water make survival difficult. Many animals in these habitats have special adaptations to stay in place, like suction-like attachments.
However, some fish, like sculpins, use their pectoral fins to grip surfaces better and resist water flow. While other bottom-dwelling fish have microscopic structures on their fins, scientists have not yet studied sculpins’ fin surfaces in detail.
Researchers from Syracuse University and the University of Louisiana at Lafayette used high-powered microscopes to study sculpins. They discovered tiny structures on the fish’s fins that may help them grip surfaces underwater, allowing them to resist strong currents and waves.
Sculpins have a unique adaptation to stay in place despite strong currents: their pectoral fins have less webbing on the bottom, allowing the fin rays to extend beyond the fin itself. This helps them grip rocks and other surfaces. Some species take it a step further, using these modified fins for walking and sensing their environment.
Previous studies show that sculpins use both hydrodynamic and physical methods to stay in place. Their small, streamlined bodies help them resist water flow, while their flexible fin rays—similar to fingers—allow them to grip surfaces.
This new research reveals an additional adaptation: microscopic surface textures on their fin rays may create friction or adhesion, further improving their grip. Kane and her team discovered these features in 2022 during fieldwork in Washington.
Using a powerful microscope, she noticed their resemblance to the fine hairs on gecko feet and consulted an adhesion expert -Austin Garner, a biology professor at Syracuse University—to investigate further.
The team studied the texture of sculpin fin rays by analyzing density, area, and length. They compared these features to those in other animals known for strong friction-based gripping, like sandpaper-like surfaces on fins.
Their findings mark the first description of these microscopic structures in sculpins, opening new research opportunities.
Garner suggests this discovery could inspire bio-inspired robots or underwater grippers designed for better adhesion. In the future, such technology might even help robots explore the ocean depths using principles borrowed from sculpins’ natural grip.
Journal Reference:
- Emily A. Kane, Austin M. Garner, Shubham Yadav, L. Ann Hume, and Tom Pesacreta. Epidermal microstructures on the paired fins of marine sculpins suggest new functional hypotheses supporting benthic station-holding. Royal Society Open Science. DOI: 10.1098/rsos.241965
