Some details on the morphological structure of planarian musculature identified by fluorescent and confocal laser-scanning microscopy

The details of the morphological organization of the body musculature in the planarians Girardia tigrina and Polycelis tenuis were investigated by histochemical staining of actin filaments with fluorescently labeled fluorescent. The whole mount preparations and frozen tissue sections of planarians were analyzed by fluorescent and confocal laser scanning microscopy. The results indicate that the muscle system is well differentiated in both planarian species and is represented by the somatic musculature of the body wall, the musculature of the digestive tract, and the musculature of the reproductive system organs in P. tenuis, which reproduces sexually. The differences and similarities between the two species in the morphological characters of the musculature, which are the size and density of myofibrils in different muscle layers, were described. The results present the basis for further studies on the regulation of muscle function in planarians.