ИСТИНА

Tantulocarida is a group of very small crustaceans (70-300µm) living as ectoparasites on other benthic crustaceans such as harpacticoid copepods, ostracods, isopods, cumaceans and tanaidaceans. Described as a new class only in 1983 they remain one of the most poorly studied groups of arthropods. Internal anatomy of the Tantulocarida who have various curious internal structures, has never been studied using TEM - the only efficient method for animals of such small sizes. Internal morphology of different stages of the two species of the Tantulocarida (Arcticotantulus pertzovi and Microdajus tchesunovi) has been studied using transmission electron microscopy and laser confocal microscopy. This constitutes the first use of TEM and CLSM for tantulocarid anatomy. Due to the parasitic mode of life tantulus larva has several unique structures inside cephalon. Double folded cuticular attachment disc is located at the anterior part of the cephalon ventrally and is used to glue tantulus to the host surface with a special substance called cement, which is released under the disc. Four cuticular canals go from the cement gland located ventrally in the posterior part of cephalon and enter unpaired proboscis. Proboscis is a cuticular organ located dorsally in the anterior part of cephalon, which can be protruded outside through a separate opening above the mouth and is used to release cement. Unpaired cuticular stylet is located centrally along the cephalon. The basal part of it is hollow, while the tip is solid, so the larva can not use it for injecting any substances into the host. The stylet serves to make a small puncture only 1µm in diameter in host cuticle. Rootlet system which is used for feeding, penetrates into the host through this tiny hole. It has now been proved that rootlet system is a direct extension of the anterior gut