Grubich, J.R.: Prey Capture in Actinopterygian Fishes: A review of suction feeding motor patterns with new evidence from an Elopomorph fish: Megalops atlanticus

Suction feeding has long been recognized as the dominant mode of prey capture among ray-finned fishes. Elshoud-Oldenhave and Osse (1976) first proposed a triphasic sequence of the suction feeding strike: 1) a preparatory phase, 2) an expansion phase, and 3) a compression phase. I review the underlying motor basis of these events during suction feeding by summarizing the major evolutionary trends identified among basal actinopterygians and advanced teleosts. One goal of this review will seek to identify functionally significant motor pattern features that are associated with major changes in the head musculature and linkage mechanics of the actinopterygian skull. Finally, the motor basis of suction feeding in the Tarpon (Megalops atlanticus) will be presented. Phylogenetically, Elopomorphs are positioned intermediately between the Osteoglossomorpha and the Euteleostei (Lauder and Liem, 1983) making them an interesting transitional group among suction feeding teleosts. Morphologically, they lack the protrusible upper jaw of advanced teleosts, but have a highly mobile anteriorly swinging maxilla. This group has also maintained a double coupling of mandibular depression through the presence of mandibular-hyoid and interopercular-mandibular ligaments. Both these oral jaw traits are shared with the basal actinopterygian fish, Amia calva (Halecomorphi), making comparisons of suction motor patterns between these distantly related species particularly interesting. Comparisons of Tarpon suction feeding motor patterns to previously documented basal and advanced actinopterygian fishes will revisit the standing paradigm that there is strong motor pattern conservation among the three phases of the suction feeding strike across a broad phylogenetic spectrum.