ENThe paper deals with Lithuanian names in biological nomenclature related with the word 'jūra' (sea). It pays most attention to names of fish (due to the large number of such names containing this word), but also the names of mammals, birds, other animals and plants are researched. An attempt is made to show the variety of names and patterns of their creation and to draw attention to the lack of systematicity and other faults. There is a settled trend in Lithuanian nomenclature to indicate the habitats of both animals and plants using components with the suffix -inis derived from various words meaning places and geographical features. On the basis of this model the connection of an animal or a plant with the sea (lives in the sea or grows near the sea) is, according to the prevailing trends of the creation of biological nomenclature, most frequently indicated by the word jūrinis. Quite a few names of fishes, mammals or invertebrates which live in the sea have been created using names of animals living on the land. In order to separate such metaphorical names of taxa from the names of the animals which are taken as the basis of the metaphor, the component jūrų is used. Thus 'jūrų kregždės' are fishes and 'jūrinės kregždės' are birds. When a specific sea needs to be indicated in the biological nomenclature, a word combination with the component 'jūros' is created. In some names the components 'jūrinis' or 'jūrų' are replaced by compounds with the component jūr-.The research shows that the components 'jūrinis', 'jūrų' and 'jūros' in the names of some similar taxa presented in Žuvų pavadinimų žodynas (Dictionary of the names of fish) (Vilnius, 2005) by J. Virbickas vary unnecessarily. Sometimes none of these components is presented even if it seems necessary when compared with the system of contiguous names. Other cases of lack of systematicity have also been noticed. There are some different taxa (species, genera) named the same. The dictionary is large, it is arranged systematically and its preparation took a long time therefore its compilers and reviewers had difficulties in ordering names presented in different places. Future ordering of the names of fish should include some corrections.