ИСТИНА

Tantulocaridans are known to be the smallest parasitic crustaceans of copepods, ostracods, cumaceans, tanaidaceans, isopods and amphipods from all over the world. The class Tantulocarida was proposed in 1983. Since then about 30 species belonging to five families have been described. Yet information on their ultrastructure and anatomy is still scarce. Two new species of Tantulocarida from different families were described. One individual (tantulus larva) of Serratotantulus chertoprudae Savchenko and Kolbasov, 2009 (Basipodellidae) was found attached to harpacticoid host from the abyssal depth of the Indian Ocean. Its tantulus is only 76μm long and represents the smallest of the described species of Tantulocarida. Microdajus tchesunovi Kolbasov and Savchenko, 2009 (Microdajidae) parasitic on a tanaid Thyphlotanais sp. is the second tantulocaridan species from the Russian Seas. New data on tantulocarid ultrastructure and morphology were obtained. Cephalothorax of a tantulus larva contains unpaired stylet hollow in its proximal part but with a solid tip, so it cannot be used for injection of any substances into a host. A funnel-shaped organ (or proboscis) has four glandular ducts which are used putatively to excrete an adhesive cement under the oral disk. A parasite produces a rootlet system which penetrates into host tissues right under the attachment site (the mouth) and is probably used for nutrition. For the first time several free swimming males of Tantulocarida (Arcticotantulus pertzovi and Microdajus tchesunovi) from the White Sea were reared. The specimens were studied thoroughly with SEM and TEM. The internal anatomy of tantulocaridan male was studied for the first time. The cephalothorax of male contains a very specific comb-shaped tissue which probably accumulates nutrients provided that adult males do not feed.