Characterization of Achromadora porosa sp. n. (Chromadorida: Achromadoridae) from the coal mines, with a detailed inference on the phylogeny of the group and the relationships between congeners.

A new species, Achromadora porosa, is described and illustrated based on morphology, morphometric and molecular characterization supplemented with scanning electron microscopic observations. Achromadora porosa sp. n. was extracted from the soil around the roots of Prosopis juliflora. The new species is characterized by numerous linearly arranged pores over the body on lateral sides, and occasionally on ventral side, indiscernible in LM; somatic setae absent; six lips, with six inner and six outer labial small, setose sensilla, nearly of equal shape and size, in two circlets and four slender, small, setose cephalic sensilla arranged closely to the circle of outer labial sensilla; amphidial fovea large, spiral with 1.5-2.0 coils, at the stoma base or 7–11 annules from anterior end; stoma funnel-shaped, asymmetrical, cheilostom divided into twelve ribs, a pair of ribs arranged in between two lips; prerectum absent; tail strongly arcuate ventrally with terminal spinneret. The phylogenetic analyses based on Bayesian inference and Maximum-likelihood method using partial SSU 18s rDNA showed close relationships among congeners of the genus besides revealing the status of family Achromadoridae with regard to families Cyatholaimidae, Selachinematidae and Ethmolaimidae. [ABSTRACT FROM AUTHOR]