Morphological and molecular identification of freshwater eutardigrade Dactylobiotus parthenogeneticus (Bertolani, 1982) in the Greater Zab River of Kurdistan Region - Iraq.

Abstract

Dactylobiotus parthenogeneticus is one of the widespread species of tardigrade all over the world. Tardigrades of this species were collected from the Greater Zab River in Erbil City-Iraq by filtering water of the river through a plankton net with a mesh of 45 µm pore. The samples were mounted on a slide with a cover slip and examined under the microscope to determine morphological characteristics and measurements. Based on these characters the species identified to be D. parthenogeneticus. To support this diagnosis, DNA barcoding techniques were applied to do molecular analysis and sequencing on the cytochrome oxidase subunit I (COI) gene. The sequence was subjected to the GenBank database of NCBI and recorded with the accession number PP140905. The result of the sequencing and molecular analysis of the cytochrome oxidase subunit I (COI) gene confirmed to be the same species diagnosed by relying upon morphological characters. This study represents one of the pioneer researches and documents on tardigrades and found D. parthenogeneticus for the first time in the Greater Zab River in Kurdistan, North of Iraq. Tardigrades play a magnificent role in different trophic levels and can be utilized as an indicator of ecosystem health.