First record of the tardigrade Echiniscus testudo (Doyère, 1840) from northeast of Iran (Heterotardigrada: Echiniscidae)

Tardigrada is a phylum closely allied with the arthropods. They are small (0.05-1.20 mm), hygrophilous micrometazoans, have four pairs of lobe-like legs and are either carnivorous or feed on plant material. Most of the tardigrade species are limno-terrestrial. In two moss and lichen samples collected in Mashhad, one heterotardigrade species was found. Echiniscus testudo (Doyère, 1840) belongs to the Echiniscidae group and differs from most of other species in this group mainly by having a different claw configuration and by some morphometric characters. This study is the first report of tardigrades from Iran.