Meeting Abstract
While venomous spines are used for defense in many ray-finned fishes, the red lionfish, Pterois volitans, is unique in that it has a diverse array of spines (13 dorsal, 2 pelvic, 3 anal). We suspect that spines located in different fins may vary in mechanical properties, dependent upon spine function (i.e. defense or locomotion,). Pterois volitans may not require all 18 venomous spines for successful defense against natural predators in the Indo-Pacific and Red Sea. They have been shown to be successful ambush hunters that confuse prey with their large fan-like pectoral fin rays. We quantified the relationship between the unique cross-sectional geometry of lionfish spines to their associated bending and compressive properties. We performed two point cantilever testing of each spine to determine the force required to break the spine and location of the break. Young’s modulus, second moment of area, and flexural stiffness were analyzed after cross-sectional area was determined at the point load. Mechanical properties of the extraordinary spine morphology of lionfish can be informative for examining evolutionary tradeoffs between protection and hydrodynamic function of fins. These tradeoffs can provide insights into how lionfish are such successful invasive species despite the apparently reduced locomotory performance.
