Abstract
The fiber type profiles of 12 muscles (M. masseter, M. trapezius, M. latissimus dorsi, M. triceps brachii, M. extensor carpi radialis, M. longissimus dorsi, M. obliquus externus abdominis, M. rectus femoris anterior, M. semitendinosus, M. semimembranosus, M. gastrocnemius and M. tibialis anterior) in eight species of amphibians (Cynops pyrrhogaster, Hyla japonica, Rana nigromaculata, Rana brevipoda, Rana rugosa, Rana limnocharis, Rhacophorus buergeri, Rhacophorus arboreus) were examined histochemically. According to the enzymatic reactions (succinate dehydrogenase, glycogen phosphorylase and myosin adenosine triphosphatase), muscle fibers were divided into three types; i. e., slow-twitch-oxidative (SO), fast-twitch-oxidative-glycolytic (FOG) and fast-twitch-glycolytic (FG) types. Moreover, according to the reactions of α-glycerophosphate dehydrogenase, aldolase and β-hydroxybutylate dehydrogenase, each of the three main types was subdivided into three types. The number of FG type fibers was higher than the other types of fibers in all species. The diameter of muscle fiber was largest in FG type fibers and smallest in SO type fibers. The fibers of muscles in the hindlimb were larger than those in the forelimb and the diameters of fibers in Cynops pyrrhogaster and Hyla japonica were smaller than those of the other six species.
