Figure 3From: Development of the ultrastructure of sonic muscles: a kind of neoteny?Ultrastructure of sonic and expaxial muscles in Pygocentrus nattereri of size class 5 (245 mm length). (A) sonic muscle of a calling fish; (B) sonic muscle of a mute fish and (C) epaxial muscle of a calling fish. my: myofibril, sr: sarcoplasmic reticulum.Back to article page