Muscle Fiber Composition of the Anterior Tibial Muscle in Several Species of Prosimians

Abstract

Muscle fiber composition in cross-sections of the venter of the anterior tibial muscle was characteristic for each species of 13 individuals of 7 species of 5 genuses of 2 families of prosimians. In the fat-tailed dwarf lemur (Cheirogaleus medius) and Miller's mouse lemur (Microcebus murinus) of lemurinae, all three types of muscle fibers were thick, and the proportion of white muscle fibers showing fast contraction was high. In slender loris (Loris tradigradus) and slow loris (Nycticebus coucang) of lorisinae, red muscle fibers were large in diameter and white muscle fibers were small in diameter, different from other species, and the proportion of red muscle fibers showing slow contraction was high, showing a pattern of dominance of red muscle fibers. In the lesser galago (Galago senegalensis), grand galago (Otolemur crassicaudatus) and Garnett's galago (Otolemur garnettii) of galaginae, muscle fibers were thin and the proportion of red muscle fibers was extremely low, while the proportion of intermediate muscle fibers, or white muscle fibers was the highest. The results suggest that it is closely correlated with the specific locomotion systems in various species of prosimians.