The integration of locomotion and prey capture in vertebrates: Morphology, behavior, and performance

For most vertebrates, locomotion is a fundamental component of prey capture. Despite this ubiquitous link, few studies have quantified the integration of these complex systems. Several variables related to locomotor performance, including maximum speed, acceleration, deceleration, maneuverability, accuracy, and approach stability, likely influence feeding performance in vertebrates. The relative importance of these measures of performance, however, depends on the ecology of the predator. While factors such as morphology and physiology likely define the limits of these variables, other factors such as motivation of the predator, prey type, and habitat structure can also influence performance. Understanding how these variables relate to feeding under a given suite of ecological conditions is central to understanding predator-prey interactions, and ultimately how locomotion and feeding have co-evolved. The goals of this article are to discuss several variables of locomotor performance related to prey capture, present new data on the relationship between locomotor and feeding morphology in fishes, discuss the evolution of prey capture in cichlid fishes, and outline some future directions for research. While suction feeding is a primary mechanism of prey capture in fishes, swimming is vital for accurately positioning the mouth relative to the prey item. Many fishes decelerate during prey capture using their body and fins, but the pectoral fins have a dominant role in maintaining approach stability. This suggests that fishes employing high-performance suction feeding (relatively small mouth) will have larger pectoral fins to facilitate accurate and stable feeding. I provide new data on the relationship between pectoral fin morphology and maximum gape in centrarchid fishes. For seven species, pectoral fin area was significantly, and negatively, correlated with maximum gape. This example illustrates that the demands from one complex system (feeding) can influence another complex system (locomotion). Future studies that examine the morphological, physiological, and functional evolution of locomotion involved in prey capture by aquatic and terrestrial vertebrates will provide insight into the origin and consequences of diversity.