The locomotory system of pearlfish Carapus acus: What morphological features are characteristic for highly flexible fishes?

摘要: The body curvature displayed by fishes differs remarkably between species. Some nonmuscular features (e.g., number of vertebrae) are known to influence axial flexibility, but we have poor knowledge the musculotendinous system (myosepta and muscles). Whereas this has been described in stiff-bodied fishes, little data on flexible fishes. In study, present new a highly fish compare them existing rigid We use microdissections with polarized light microscopy study three-dimensional anatomy myoseptal tendons, histology immunohistology insertion muscle fiber types into μ-CT scans skeletal anatomy. Results compared published from identify four important morphological differences Carapus acus: (1) bears short tendons horizontal septum, whereas elongated tendons. (2) lateral its myosepta, bear Because retains high flexibility. contrast, restrict flexibility able transmit anteriorly generated forces through long down tail. (3) distinct epineural epipleural these weak or absent As firmly connect vertebral axis skin Carapus, consider constrain displacement during extreme flexures. (4) Ossifications only C. acus other more functional reasons for remain unexplained. J. Morphol., 2012. © 2011 Wiley Periodicals, Inc.