Myotomes of adult teleost have a folded shape often referred to as chevron shape. The chevron shape has been proposed to be optimal for the alternating body bending during swimming. Much less is known about which processes underly the ontogenetic development of the myotome shape. As far as we know, the only study that deals with this topic was done by Van Raamsdonk et al.(1974, 1977, 1979). They conclude” that the lateral body movements have both a shape determining and a shape-stabilizing role during the early stages of somite morphogenesis. We aim to shed new light on the mechanisms that shape the my- otome chevrons by developing and analysing a mathematical model of the interactions between muscle fibres and somite boundaries.