Meeting Abstract
P1.200 Friday, Jan. 4 A comparative study of body shape and swimming kinematics in pholid and stichaeid fishes REYNAGA, CM*; FERRY, LA; CLARK, AJ; Univ. of California, Santa Cruz; Arizona State Univ.; College of Charleston cmreynag@ucsc.edu
Body shape may provide a potential explanation for the variation in swimming kinematics across fish groups. The anguilliform body plan is one extreme body shape that strongly influences swimming behavior. Anguilliform teleosts are phylogenetically and morphologically diverse, especially with respect to their 2nd major body axis (body depth/width). We examined the effects of second major body axis on the swimming kinematics in two teleost families with eel-like bodies: the Pholidae and Stichaeidae. In four species of pholids (Apodichthys purpureus, Pholis laeta, Pholis ornata) and three species of stichaeids (Anoplarchus purpurescens, Xiphister muscosus, Xiphister atropurpureus, Lumpenus sagitta), we recorded standard length, and the body widths and body depths at 10% standard length increments. Second major axis was defined as the ratio between body depth and width. As this ratio changed with length along the body, a single unifying metric, the “body shape slope” was used to characterize body shape across individuals; this is the slope of the increasing ratio of body depth to width along the caudal region. Forward swimming speed, caudal fin beat frequency, body wavelength frequency, and maximum amplitude were examined from high-speed video recordings at steady swimming speeds ranging from 13.5 – 78.0 mm/s. Pholids, with greater body depths, are morphologically distinct from stichaeids, which have greater body widths. Although pholids and stichaeids varied in body plans, body shape and second major axis were not strong predictors of wave frequencies, maximum body wave amplitudes, and caudal fin beat frequencies relative to standard lengths. The results demonstrate the complexity between body shape and locomotor performance within the body plan of the two teleost families.
