Fig. 12. Polarized light image of two adjacent and parallel collagen fibre layers of the epaxial multilayers of a carp (dissected form the anal region along the trunk). The muscle fibres were carefully removed by microdissection to reveal the collagen fibre bundles. The main directions of the collagen fibres are indicated by lines with arrowheads. The top layer, visible at the right hand side, is largely removed to reveal the second layer. The orientations of the collagen fibre bundles in the two layers are very different. The functional relevance of the jump in fibre orientation between the layers for the force transmission is discussed in the main text. In vivo, these layers are predicted to slide parallel to each other during muscle contraction of the muscular system (to allow for the jump in added shear, see main text). Some other fibres with deviating orientations are visible that do not form part of these layers. Scale bars, yellow: 51.24 µm; red, 46.66 µm.