Prey capture in actinopterygian fishes: A review of suction feeding motor patterns with new evidence from an elopomorph fish, megalops atlanticus

Abstract

SYNOPSIS. Suction feeding is recognized as the dominant mode of aquatic prey capture in fishes. While much work has been done identifying motor pattern variations of this behavior among diverse groups of actinopterygian fishes, many rayfinned groups are still not represented. Further, the substantial amount of inherent variation in electromyography makes much of the pioneering work of suction feeding motor patterns in several basal groups insufficient for evolutionary comparisons. Robust evolutionary comparisons have identified conserved qualitative traits in the order of muscle activation during suction feeding (jaw opening > buccal cavity expansion > jaw closing). However, quantitative traits of suction motor patterns (i.e., burst durations and relative onset times) have changed over evolutionary time among actinopterygian fishes. Finally, new motor pattern evidence is presented from a previously neglected group, the Elopomorpha. The results suggest that future investigations of the muscles influencing lateral expansion of the mouth cavity and head anatomy may provide valuable new insights into the evolution of suction feeding motor patterns in ray-finned fishes. In addition, the evidence illustrates the value of comprehensive EMG surveys of cranial muscle activities during suction feeding behavior.