Stuck on you How pelvic girdle morphology influences adhesion

January 3 – Febuary 28, 2021

Meeting Abstract

P4-2  Sat Jan 2  Stuck on you: How pelvic girdle morphology influences adhesion Palecek-McClung, AM*; Huie, JM; Cohen, KE; Donatelli, CM; Summers, AP; Clemson University, Clemson, SC; George Washington University, Washington, DC; University of Washington, Friday Harbor, WA; University of Ottawa, Ottawa, ON; University of Washington, Friday Harbor, WA

Pelvic suction discs have independently evolved multiple times in bony fishes. The discs are used to adhere to substrates during climbing or station-holding and show tremendous diversity in musculoskeletal morphology and performance. These suction discs vary in size, texture, the substrates they are used on, and their internal skeletal morphology. We compared how the shape of the pelvic girdle contributes to adhesive performance in four groups of bony fishes- clingfishes, gobies, snailfishes, and lumpsuckers. We used CT data to make 3D printed models of pelvic girdles and embedded each model into a standardized silicone suction cup. We measured the pull-off forces on 3 substrates varying in surface roughness. Generally, bioinspired suction cups followed comparative live-animal adhesive performance trends, and performance increased as surface roughness increased. Though the clingfish (Gobiesox) has the highest performing suction disc in nature, its suction cups yielded poor adhesive performance. Most fishes with suction discs have a modified pelvic girdle, but clingfish suction discs are supported by both pectoral and pelvic girdle elements. Our low clingfish values are likely due to the absence of the pectoral girdle skeletal elements. We have established that this simple modeling technique will track the real world results of pull off tests for suction performance. We will now use the technique to explore the finer scale diversity of skeletal support structures in fishes. This is especially interesting work in light of the immediate biomimetic implications on manufactured suction devices.

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