A new eutardigrade from Costa Rica with taxonomical and zoogeographical remarks on Costa Rican tardigrades

Abstract

ABSTRACTIn a moss sample collected in Costa Rica, 63 specimens and 13 eggs of the new species were found. Mesobiotus pseudopatiens sp. nov. belongs to the harmsworthi group and is most similar to Mesobiotus patiens, but it differs from it mainly by smaller eggs, longer flexible portions of egg processes and certain morphometric characters of adults. In addition, after re-examination of specimens of the genus Milnesium collected in Costa Rica, a new record of Milnesium kogui may be added to Costa Rican fauna. The paper also discusses taxonomical problems and the zoogeography of Costa Rican tardigrades, which partially agree with hypotheses of Great American Biotic Interchange and Mexican Transition Zone. A large number of so-called ‘Costa Rican species’ are doubtful taxa with ‘cosmopolitan’ distribution; the largest number of species, however, have tropical/subtropical or neotropical distribution. Certain species from colder regions are also present in the mountains of Costa Rica.http://zoobank.org/urn:lsid:zoobank.org:pub:F6F6195E-0888-4279-A3AF-422642F8B40