Figure 26 Electron micrographs of the slow swimming muscles of two antarctic fish, (a) The icefish (Chaenocephalus aceratus). The mitochondria are so large and numerous that they occupy more space within the muscle fibre than the contractile myofibrils. (b) Notothenia gibberifrons. The fibres contain fewer mitochondria and the myofibrils are more regularly arranged than in (a). Abbreviations: my, myofibrils; mt, mitochondria; cap, capillary; lp, lipid droplet