Elongated, cylindrical, unsegmented worm; includes a number of plant and animal parasites. (Aydın, I., Küçük, E., Polat, H., Haşimoğlu, A. & Altuntaş, A. 2023. Black Sea turbot – A comprehensive production manual. FAO Fisheries and Aquaculture Technical Paper, No. 693. FAO, Rome. https://doi.org/10.4060/cc6224en)