Meeting Abstract
Jaw (premaxillary) protrusion is thought to be a key innovation correlated with the subsequent radiation and diversification of fishes. Extreme amounts of protrusion are associated with suction prey capture, often on highly elusive prey. Notable examples of this are the sling-jaw wrasse Epibulus insidiator and the cichlid Petenia splendida; wrasses and cichlids both being extremely speciose clades of fishes. Interestingly, king-of-the-salmon or ribbonfish, Trachipterus altivelis, also are capable of extreme jaw protrusion. The ribbonfishes as a group (Trachipteridae, Lampriformes) are not terribly diverse, with only around 10 extant species, yet all members appear to show the capacity for impressive jaw protrusion. Ribbonfish are laterally compressed, deep-pelagic, and vertically migrating. They consume primarily zooplankton and perhaps small fish and squid and move to the surface at night with the deep scatter layer. They have highly protrusile jaws, but lack teeth. Here we present new findings regarding the anatomy of ribbonfish and close relatives, as well as the implications for jaw protrusion and prey capture.
