Family Cyclopidae Dana, 1846

Only two cyclopoid species were included in this study, Tropocyclops parvus Kiefer and Thermocyclops inversus Kiefer, both from Peten Lake. The former species, recently re-described by Dumont (2006), is an extremely small (less than 0.4 mm) pelagic copepod. These two genotypes showed deep barcode divergence (>40%), but members of each species showed little sequence variation (0.02%).