Invasive and non-invasive methods to investigate on the musculotendinous system in teleost fishes (e.g. pearlfish)

Aims The locomotory system of fishes is composed of muscles (=myomeres) and myosepta attaching along the vertebral column. Both systems are conflated to the so called musculotendinous system. A myoseptum separates subsequent blocks of muscles and is characterized by a complex 3D arrangement of specific anteriorly and posteriorly pointing cones projected into the musculature. In previous investigations, this system has been described in stiff bodied fishes (e.g. lamnid sharks, tunas) and some flexible specimens (e.g. eel, pearlfish). Commonly, investigating the soft tissue of the musculotendinous system was realized with long-lasting procedures like ̳clearing and staining‘ but also histological serial sections. These methods are destructive and invasive and do not guarantee evaluable results. The aim of this study is comparing different methods of investigation and the benefits of using micro-CT scanning.