In many arthropods, endosymbiont bacteria have been detected that can influence their hosts' biology and reproductive system. Here, we screen a first set of non-marine ostracod specimens for the presence or absence of Cardinium, one such endsymbiont, to confirm results that were obtained with classic Sanger sequencing. Our study is the first on endosymbionts in non-marine ostracods and shows that the Cardinium bacteria, which we found in non-marine ostracod, is a novel group and only distantly related to Cardinium from other, mostly terrestrial arthropods.