Meeting Abstract
While much of the functional work on suction feeding has involved members of Acanthopterygii, a much older cypriniform radiation led to almost 4000 species filling nearly every freshwater trophic niche. Within the great majority of acanthomorph clades that have been investigated suction feeding and the underlying morphology responsible for the generation of rapid suction have been largely conserved. This conserved feeding apparatus is primarily aimed at increasing the force experienced by the prey item thus making a strike more effective. Cypriniform feeding anatomy is comprised of a number of novelties used for benthic feeding, which characterized early members of this clade. The modified cypriniform structure of the oral jaws represents a case where a particular type of suction feeding allowed for probing the benthos with a more functionally maneuverable feeding anatomy. Requisite modifications included origin and elongation of a median kinethmoid, duplications of certain divisions of the adductor mandibulae muscles, and a dorsal muscular palatal organ. The elongated kinethmoid (coupled with modified adductor muscles) allowed for a type of premaxillary protrusion that decouples the upper and lower jaws, enables premaxillary protrusions with a closed mouth, and facilitates benthic sorting. This greatly modified benthic feeding morphology allowed for a degree of maneuverability and variation in kinematics not seen within most acanthomorphs. Later cypriniform radiations into piscivorous or planktivorous feeding guilds were associated with shortening of the kinethmoid and simplified adductor morphology. Although this suite of morphological novelties seemingly evolved for benthic feeding, with minimal modifications these anatomical features were later coopted during radiations into different functional niches.
