ИСТИНА

Kamptozoa is a small group of marine invertebrate animals with uncertain phylogenetic position. New morphological investigations are needed to find out kamptozoan relationships. In this study the myoanatomy of larval and adult stages of [Barentsia discreta] was investigated using confocal laser scanning microscopy. The calyx musculature of adult stage comprises longitudinal muscles of body cavity and muscles associated with the digestive tract. At the base of the tentacles the atrial ring muscles are found. The musculature of each tentacle consists of one pair of thick longitudinal muscles and two pairs of fine longitudinal muscles. The star-cell complex is situated in the calyx-stalk junction. The small muscular bulbus — slightly expanded apical stalk part with bands of longitudinal muscles on the periphery – is located below. The thin part of the stalk has no muscles. In the muscle base longitudinal fibers are located on periphery. Muscles don't pass in the stolon. The musculature of the larvae includes prototroch ring muscles, episphere ring muscles , four pairs of inner longitudinal muscles and numerous prototroch longitudinal muscles. The comparison of the myoanatomy of [B. discreta] with the myoanatomy of the solitary entoproct species Loxosomatidae indicates that the general muscular structure is identical in all Kamptozoa and includes central muscles of the calyx, atrial ring muscles, tentacle muscles and muscles associated with the digestive tract.