The harpacticoid families Ancorabolidae Sars, 1909 and Argestidae Por, 1986, are both regarded as representatives for deep-sea meiofauna, either being worldwide distributed with predominant occurrence in deep-sea habitats. In contrast to Ancorabolidae, Argestidae include more described species, show higher frequency and higher individual numbers in deep-sea samples. The body of Argestidae is of compact, cylindrical shape whereas the body of Ancorabolidae appears to be more delicate through conspicuous processes on all body somites, indicating different life styles and needs to the habitat in the two families. Anyhow, due to clear morphological features in the two families and possibly different preferences, Ancorabolidae and Argestidae are both excellent groups for biogeographical studies on species level. To date, predominantly data from the Atlantic region are available. Thus, the actual distribution might be misrepresented by the generic and the specific distribution focused on the Atlantic ocean including the southern ocean. One single record of Ceratonotus steiningeri George, 2006 in the south Atlantic as well as in the Pacific ocean leads to the assumption, that there indeed is a species distribution exceeding only Atlantic dispersal. This is supported by five additional records on generic level of argestid and ancorabolid specimens from the Atlantic, the Southern, the Indian, and the Pacific ocean.