Meeting Abstract
60.3 Saturday, Jan. 5 Feeding morphology and kinematics in surfperches (Embiotocidae: Perciformes): evolution and functional consequences QUARANTA, K.Q.*; FERRY-GRAHAM, L.A.; Moss Landing Marine Laboratories kquaranta@mlml.calstate.edu
Morphological differences in feeding mechanisms are assumed to relate to differences in feeding mode and prey capture performance. Such differences are thought to explain how the Embiotocidae (Perciformes, Acanthopterygii) manage to co-exist in spite of tightly overlapping geographic ranges and habitats. Embioticids can possess one of several different feeding modes: browser-picker, crusher, and oral-winnower. We hypothesize that mechanical models, such as the anterior jaws 4-bar linkage model, can be used to interpret the differences in underlying morphology, tying anatomy to feeding mode and ultimately performance. Several specimens (n ~ 10) representing each of the 14 genera of Embiotocidae were examined using the concepts of lever mechanics to quantify the anterior jaw musculoskeletal system; these incorporated replicates from the same species sampled from distant locations in order to examine geographic variation in mechanics. Preserved specimens were dissected and the components of the anterior 4-bar linkage measured along with other morphological variables associated with feeding (e.g. gape, jaw protrusion, jaw levers, and muscle mass). Trends in these variables among species seem to provide a basis for variation in feeding mode. However, our findings do not suggest that function is reflected in the underlying morphology, but that behavior linked to evolutionary relationships is a primary determinant of feeding ecology in embiotocids. A subset of these species was investigated using high-speed video (250 – 500 fps) in order to identify differences in prey capture behavior with different feeding modes. This kinematics study further suggested that differences in the feeding mechanism directly relates to differences in feeding behavior and not underlying morphology.
