TY - JOUR AU - Schmelz, Rüdiger M. AU - Klinth, Mårten J. AU - Chalkia, Christina AU - Anastasiadou, Pelagia AU - Vavoulidou, Evangelia PY - 2019/12/01 Y2 - 2024/03/28 TI - Enchytraeus demutatus sp. nov. (Enchytraeidae, Oligochaeta) has characters hitherto unrecorded in the genus JF - SOIL ORGANISMS JA - SOIL ORG VL - 91 IS - 3 SE - ARTICLES DO - 10.25674/so91iss3pp87 UR - https://soil-organisms.org/index.php/SO/article/view/108 SP - 87–96 AB - <p>A new species of enchytraeids with peculiar characters is described, <em>Enchytraeus demutatus</em> sp. nov. The species differs from all known species of <em>Enchytraeus</em> in features of the oesophageal appendages and the male efferent apparati. The oesophageal appendages insert ventro-laterally below the pharyngeal pad and not dorsally behind the pad, as is usual in the genus; furthermore, their histology is different. The male efferent apparati have each an unusually wide and short vas deferens, and accessory glands are attached to the inner surface of the male glandular bulb, in close vicinity to the male pore. The remaining characters agree with the genus diagnosis of <em>Enchytraeus</em>, notably the presence of testis sacs and oesophageal appendages. The bisetose worms are about 5 mm long and 0.2–0.3 mm wide. The peculiarities of the oesophageal appendages raised the possibility to place the species in a new genus. DNA sequencing was performed to provide molecular identifiers and to assess the generic placement of the species. The molecular phylogenetic analysis, based on a concatenation of the six genetic markers 12S, 16S, 18S, 28S, COI and H3 placed <em>E. demutatus</em> inside the well-supported (PP  =  0.99) <em>Enchytraeus</em> clade and not outside, hence the new species is to be considered a member of <em>Enchytraeus</em>. The tree includes species that cover a wide range of the morphological diversity in <em>Enchytraeus</em>; here <em>E. demutatus</em> sp. nov. groups with a sub-branch that includes the other bisetose species, also the fragmenting ones, but also one species with 3 chaetae per bundle; whereas species of the <em>E. buchholzi</em>-group and the <em>E. albidus</em>-group, respectively, form clades of their own. <em>E. demutatus</em> sp. nov. was found in soil samples derived from a tomato field of a private greenhouse farm in the regional division of Ilia, West Greece, together with abundant <em>E. bigeminus</em>.</p> ER -