Two new Halamphora (Bacillariophyta) species from the marine coasts off Livingston Island, Antarctica.

During a survey of the marine benthic diatom flora on the coasts off Livingston Island (South Shetland Islands, Maritime Antarctic Region), two Halamphora species that could not be identified based on the currently available literature, were observed. Detailed light and scanning electron microscopy observations and thorough comparison with similar taxa in the literature revealed that both taxa should be described as new species. The first taxon, Halamphorakenderoviana sp. nov. , was most likely misidentified in past Antarctic studies, and included within the range of another taxon, Halamphoracoffeaeformis . Analysis of literature data showed that the second new taxon, Halamphoramoncheviana sp. nov. , has been previously reported from the Antarctic Continent (but as an unidentified species). The new taxa are compared with similar Halamphora taxa worldwide. Data on their ecology and distribution are also provided.