Meeting Abstract

70.4  Jan. 7  Why the long face? Prey capture in trumpetfishes HUSKEY, Steve*; QUINTERO, Reyes; Western Kentucky University; Western Kentucky University steve.huskey@wku.edu

Feeding in fishes has received a tremendous amount of attention to better understand the evolution of vertebrate feeding mechanisms. Application of technologies such as high-speed video, sonomicrometry, and DPIV have assisted in helping researchers gain a thorough understanding of the complexities of the interaction between a fish and its environment, especially during feeding. However, we lack detailed knowledge of what happens to pressure within the buccal cavity of a feeding fish. Likely the result of no way to visualize flows within the buccal cavity and the morphological limitations imposed by most fishes, our limited understanding can be expanded through the use of long-snouted fishes able to accommodate multiple pressure sensors within the mouth. Trumpetfish were implanted with two sensors positioned at the caudal and rostral ends of the buccal cavity to better understand pressure changes during feeding. Peak pressures occurred at 0.026ms and 0.030ms, respectively, with pressure dropping first within the rear of the buccal cavity (mean -22.73kPa) and being translated through the elongate skull and jaws to the tip of the mouth 4ms later (mean -18.00kPa). Pressures in the caudal portion of the buccal cavity were, on average, 4.73kPa greater than at the oral jaws, indicating a precipitous loss of pressure within the elongate buccal cavity. Subambient pressure was accomplished via tremendous cranial elevation produced through contraction of epaxial muscles and translation through large sesamoid tendons down a long portion of the fish�s body. While the overall body shape of trumpetfishes certainly yields ecological success, the long moment arm of the skull and the precipitous decrease of buccal pressure within the mouth suggest a trade-off between body shape and subambient pressure translation.