ИСТИНА

The tantulocaridans represent tiniest exoparasites of other benthic crustaceans. They have a unique life circle among crustaceans characterized with absence of true subsequent molts. The material on two tantulocarid species including different instars was collected at the White Sea during 2004-2007. These are Arcticotantulus pertzovi parasite of the harpacticoid genus Pseudobradya sp. and a new species of family Microdajidae parasite of the tanaid genus Typhlotanais sp. Additionally, a material on a new species of the family Basipodellidae (a tantulus larva) from deep-sea of Indian Ocean has been examined. The morphology of tantulus larva, «parthenogenetic female» and male was studied with SEM and TEM. Both larval cephalon of tantulus and cephalothorax of male lack the lattice organs, representing a synapomorphy for the class Thecostraca. Stylet, a funnel-shaped organ and rudimental, closed cuticular gut were observed inside the cephalon of larva. Stylet is covered by several layers of thick cuticle, hollow at base, at least, and situated within special chamber inside the gut. A funnel-shaped organ lies inside an own chamber above the gut, and having a separate opening above mouth aperture. A tip of funnel-shaped organ ends with dense cuticle. Four canals or peculiar cavities putatively of secretory nature open into a funnel-shaped organ. They may produce special cement glues a tantulus to host. Probably, a gut of tantulus penetrates inside a host through a puncture made with stylet.