Meeting Abstract
31-6 Friday, Jan. 4 14:45 – 15:00 The art of unsticking: Biomechanics of terrestrial adhesion in the amphibious fish Kryptolebias marmoratus STANDEN, EM*; TURKO, AJ; University of Ottawa, Canada; University of Guelph, Canada estanden@uottawa.ca http://www.standenlab.com/
The mangrove rivulus Kryptolebias marmoratus is a small amphibious fish that inhabits tropical mangrove swamps. During the dry season, these aquatic habitats can disappear, forcing fish to seek water elsewhere or burrow into logs and debris until water returns. Water conditions in these habitats can also become acutely unfavourable (e.g. hypoxia, elevated H2S, too hot), and mangrove rivulus respond by escaping onto land. Conspecific aggression can also cause fish to leave water and travel over land to unoccupied pools. Mangrove rivulus have developed a dynamic locomotory repertoire and they readily move between water and land with a large amount of control. Rivulus emerse from water in an explosive behaviour and readily stick above the water line to mud, wood and leafy substrates (in the wild), or glass and plastic (in the lab). The fish can easily adhere to vertical and even inverted horizontal surfaces and surface roughness and humidity do not appear to hinder their performance. More impressively mangrove rivulus perform controlled ‘unsticking’ maneuvers and can gain height by jumping from vertical surface to vertical surface in a seemingly organized and directional manner. This study uses high-speed video and force measurements in combination with fine anatomical description of the fins, scales, and trunk musculature to determine the mechanisms used to control adhesion-based maneuvering in these tiny fish. Body orientation and surface area contact are highly variable during unsticking events suggesting that another smaller scale mechanism is acting to provide precise control for surface adhesion. Preliminary data points to skin surface structure as a possible mechanism to control release timing during unsticking events in this tiny amphibious fish.
