ИСТИНА

The representatives of the Lumbrineridae family have a complex jaw apparatus that is typical for the Eunicida order. However, there are only a few studies on the fine morphology of the eunicidan jaws, and none of them are on the Lumbrineridae family. The present study describes the fine morphology of the jaw apparatus of Scoletoma fragilis, the common lumbrinerid from the White Sea. Three different types of jaw plate ultrastructure were observed in the pharynxes of adult and juvenile worms. In general, our results correspond with those of previous studies on other eunicidan families. However, one of the jaw types was not described in the literature before. It is characterized by heterogeneous sclerotization and is found in specific areas of the maxillary apparatus.