Anatomy of digestive system and feeding mechanism of Quatuoralisia malakhovi (Hemichordata, Torquaratoridae)

An anatomical study of the digestive system of the deep-sea enteropneust Quatuoralisia malakhovi was carried out. It is shown that the lateral collar lips are twisted in such a way that they form a ciliary groove leading to an internal channel through which the collected detritus particles are transferred to the peripheral pharyngeal channels. The size of the selected particles ranges from 1–6 μm to 100–200 μm, which corresponds to feeding on the remains of planktonic diatoms. The importance of the faecal cord as an anchor holding the heavily watered jelly-like body of Torquaratoridae at the sea floor during feeding is noted.