ИСТИНА

Tantulocarida is a group of exclusively ectoparasitic crustaceans, that utilise copepods, isopods, amphipods, ostracods, cumaceans or tanaidaceans as hosts. Parasitic as well as free swimming stages of tantulocaridans could be found in a wide range of marine meiobenthic biotops from shallow water corral sand to the deepest areas of the World ocean and even anchialine caves. However, until now Tantulocarida has never been recorded to parasitise plankton dwelling Crustacea. During the German-Russian expedition KURAMBIO II abundant material on Tantulocarida was collected from sediment samples obtained from ultraabyssal depths of the Kurile-Kamchatka trench. However, for the first time Tantulocarida were also detected on the planktonic hosts collected with the Multiple Plankton Sampler (MultiNet). Two small parthenogenetic females of yet unidentified tantulocaridans were found attached to the two specimens of harpacticoid copepods of the family Aegisthidae (Stratiopontotes sp.) collected from 6000-3000 meters depth at two different stations. In both cases infected hosts were obtained from the deepest horizon of the MultiNet deployment, but this was still more that 2000m above the bottom. Thus, the hosts could not be assigned to benthopelagic species, but more likely they have typically planktonic mode of life which is proved by various adaptations such as, for example, extremely elongated caudal rami. Complex life cycle of Tantulocarida involves both free living and parasitic stages as well as sexual reproduction and parthenogenesis. How is it functioning in the three-dimentional environment of the planktonic communities?