Observations of Irish Parechiniscus Cuénot, 1926 (Heterotardigrada: Echiniscidae) Convey New Information (And Questions) About the Genus

Abstract

ABSTRACT:Parechiniscus Cuénot, 1926 is a monotypic genus of tardigrades that includes among its characteristic features the uncommon trait of unpaired dorsal cuticular plates at the position of each of the first three leg pairs. Our morphological analyses of Irish Parechiniscus specimens, which included scanning electron microscopy, led to a new interpretation of configuration and details of the dorsal cuticular plate morphology in this genus. We also provide comments on Parechiniscus morphometry, sensory organs and sexual system. New emendations to the genus diagnosis based on our findings are proposed. Additionally, we record Echiniscus spiniger Richters, 1904 and Testechiniscus spitsbergensis spitsbergensis (Scourfield, 1897) from Ireland for the first time.