Zur Biologie des marinen HeterotardigradenTetrakentron synaptae

The life cycle ofTetrakentron synaptae Cuénot, 1892, a tardigrade closely associated with the sea cucumberLeptosynapta galliennei Herapath, was investigated in the littoral zone at Roscoff (France). Eggs and juveniles were found only in June and July, adults only from May to October. There are vagile males and stationary dwarf males. The dorsoventrally flattened body, an enlarged slimy epicuticle in females and dwarf males, the full set of claws also in juveniles, and the anus, which is in a dorsocaudal position, are indicative for an epizoic, sessile life. There is strong evidence thatT. synaptae punctures the cells ofL. galliennei and sucks out their content, which is indicative of parasitism.