Test of hypothesis of cosmopolitanism of many species of the deep-sea genus Acantholaimus

and a review of this genus

Cosmopolitan species are known among shallow-water nematodes. However deep-sea nematodes are usually investigated on genus level, because of the huge quantity of species. Therefore the information on the species distribution of deep-sea nematodes using morphological data exists, but very scarce. The molecular taxonomy data on deep-sea nematodes completely absent. Acantholaimus is one of the most typical and species-rich deep-sea nematode genera. Basing on morphological descriptions we can conclude, that many Acantholaimus species seem to be cosmopolitan. We started a study of this genus using methods of traditional taxonomy, molecular taxonomy, and histology. In our work, we plan to find similar Acantholaimus morphotypes from different regions and apply methods of molecular taxonomy to find out whether these morphotypes really belong to the same species. We will use samples from the Tropical Eastern Pacific, North-Western Pacific, North Atlantic, and the Antarctic.