Meeting Abstract

71.3  Tuesday, Jan. 6  Integrated diversification of suction feeding performance in centrarchid and cichlid fishes WAINWRIGHT, P.C.**; HOLZMAN, R.A.; MEHTA, R.S.; HULSEY, C.D.; Univ. of California, Davis; Univ. of California, Davis; Univ. of California, Davis; Univ. of Tennessee, Knoxville pcwainwright@ucdavis.edu

Suction feeding ability has been shown to have a complex underlying basis with numerous avenues of musculoskeletal biomechanics and behavior leading to higher performance. In this study we explored the degree to which this complexity was integrated during the diversification of two groups of predatory suction feeding fishes, centrarchids and the heroine cichlids of Central America. We focus on the magnitude of hydrodynamic forces the fish can exert on the prey as a measure of performance. These forces are partly due to the ability to generate high velocity, high acceleration water flow during suction feeding, which can be estimated from cranial morphology with Suction Index. Fish can also increase the water flow in the prey frame of reference with faster jaw protrusion and appropriate timing of strike kinematics. We measured Suction Index and jaw protrusion speed in 17 centrarchid species and 14 heroine cichlids, and asked how tightly correlated the evolution of these features were during the diversification of the two groups. In both groups there is a significant relationship between independent contrasts of Suction Index and jaw protrusion speed. These results show that structurally independent determinants of suction feeding performance were integrated during these two radiations. We suggest that the mechanical trade-off between the ability to exert high suction forces on prey and the ability to capture large volumes of water is a dominant axis of diversification in fish feeding systems.