A proposed order-level classification in Oligochaeta (Annelida, Clitellata).

The purpose of our contribution is to propose a robust and practical order-level classification of the families of Oligochaeta, that is, non-leech Clitellata. The order level is mandatory in Linnaean rank-based classification and is also required in many internet-based biodiversity databases. However, it has received little attention in oligochaete systematics, and the few available order-level classifications of Oligochaeta no longer represent phylogenetic relationships adequately. Our proposal is based on corroborated molecular phylogenetic evidence and takes as benchmarks class level for Clitellata, subclass level for Oligochaeta and Hirudinea, and order level for Crassiclitellata, the monophylum that includes most of the earthworm taxa. As a result, eleven orders are proposed: Alluroidida Timm Martin, 2015; Capilloventrida Timm, n. ordo; Crassiclitellata Jamieson, 1988; Enchytraeida Kasprzak, 1984; Haplotaxida Brinkhurst Jamieson, 1971; Lumbriculida Brinkhurst Jamieson, 1971; Moniligastrida Brinkhurst Jamieson, 1971; Narapida Timm, n. ordo; Parvidrilida Timm, n. ordo; Randiellida Jamieson, 1988; Tubificida Jamieson, 1978. This order-level classification is robust and easily adaptable to future insights into phylogenetic relationships.

A literature revision of Pararhyacodrilus Snimscikova, 1986, with the erection of a new genus, Semernodrilus gen. nov. (Oligochaeta, Tubificidae, Rhyacodrilinae).

The aquatic oligochaete genus Pararhyacodrilus Snimscikova, 1986 included four species, P. aspersus Snimscikova, 1986, the type species, P. palustris (Ditlevsen, 1904), P. ekmani (Piguet, 1928), and P. confusus Semernoy, 2004. Rhyacodrilus palustris (Ditlevsen, 1904) and R. ekmani var. profundalis Lastockin, 1937, have been associated with Pararhyacodrilus, as a result of different nomenclature-related confusions. A new taxon, Semernodrilus gen. nov., is erected for the Baikalian Pararhyacodrilus confusus Semernoy, 2004. As a result, Pararhyacodrilus includes two species, P. aspersus and P. ekmani.

A new species of Enchytraeus (Enchytraeidae, Oligochaeta) from the profundal of Lake Van, the world's largest soda Lake (Turkey, East Anatolia).

Enchytraeus polatdemiri sp. nov. (Enchytaeidae, Oligochaeta) was discovered in the framework of a sampling campaign of the benthic invertebrate fauna of the hyperalkaline Lake Van in Eastern Anatolia, Turkey, the third-largest closed lake and the largest soda lake on Earth. It was the only oligochaete species found in all samples. DNA sequencing included a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene, and a fragment of the nuclear histone 3 (H3) gene. For comparison, specimens from laboratory cultures of E. albidus Henle, 1837, a widespread and morphologically similar species, were sequenced as well. The new species differs from E. albidus in comparatively small body size, 2 or 3 chaetae per bundle, saddle-shaped clitellum, absence of a copulatory field between the male pores and vasa deferentia usually not extending beyond the clitellum. The individual gene trees of COI and H3, as well as the combined phylogenetic analysis of both trees, recovered Enchytraeus polatdemiri sp. nov. as a monophyletic group within the genus Enchytraeus, closely related to E. albidus, but with an average p-distance for COI of 14.5 %. E. polatdemiri sp. nov. may have evolved from a local population of Enchytraeus albidus, a species well-adapted to changing salinity conditions, or from a common ancestor into an extremophile species that dwells and reproduces in the profundal of a strongly alkaline soda lake.

Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp..

Lake Hazar is an alkaline oligotrophic lake of tectonic origin, located in the Eastern Anatolia region in Turkey, 1248 a a.s.l. Its surface area is 80 km2, the average depth 93 m and maximum depth 205 m. The lake and its surroundings an under protection as a region of historical value. During the present study (2007-2012), samples were taken from 15 stations located at a depth of 2-200 m. Oligochaeta comprised 69% of the total invertebrate abundance. The profundal olgochaete fauna was found to consist of only three tubificid taxa, all of the subfamily Tubificinae. Potamothrix alatus hazaricus Timm & Arslan, n. ssp. was dominating anywhere down to maximum depths while Psammoryctides barbatus (Grube) and Ilyodrilus(?) sp. occurred seldom. All three are new records for Lake Hazar. Potamothrix alatus hazaricus shares the "winged" body shape in its genital region with the nominal, brackish-water subspecies P. a. alatus Finogenova, 1972, and the lateral position of the spermathecal pores and the shape of the ventral chaetae with the freshwater subspecies P. a. paravanicus Poddubnaja & Pataridze, 1989 known from Transcaucasian lakes. The mitochondrial COI barcoding gene suggests long separation between the two taxa, but the nuclear ITS region shows no variation. The generic position of Ilyodrilus (?) sp. remains obscure since its internal genitalia could not be studied.

New species in the Old World: Europe as a frontier in biodiversity exploration, a test bed for 21st century taxonomy.

The number of described species on the planet is about 1.9 million, with ca. 17,000 new species described annually, mostly from the tropics. However, taxonomy is usually described as a science in crisis, lacking manpower and funding, a politically acknowledged problem known as the Taxonomic Impediment. Using data from the Fauna Europaea database and the Zoological Record, we show that contrary to general belief, developed and heavily-studied parts of the world are important reservoirs of unknown species. In Europe, new species of multicellular terrestrial and freshwater animals are being discovered and named at an unprecedented rate: since the 1950s, more than 770 new species are on average described each year from Europe, which add to the 125,000 terrestrial and freshwater multicellular species already known in this region. There is no sign of having reached a plateau that would allow for the assessment of the magnitude of European biodiversity. More remarkably, over 60% of these new species are described by non-professional taxonomists. Amateurs are recognized as an essential part of the workforce in ecology and astronomy, but the magnitude of non-professional taxonomist contributions to alpha-taxonomy has not been fully realized until now. Our results stress the importance of developing a system that better supports and guides this formidable workforce, as we seek to overcome the Taxonomic Impediment and speed up the process of describing the planetary biodiversity before it is too late.

Description of two new actinosporean types from a brook of Fuji Mountain, Honshu, and from Chitose River, Hokkaido, Japan.

Actinospore infection of oligochaetes living in the mud of 3 freshwater biotopes in Japan was studied. Using the cell-well plate method, a new aurantiactinomyxon type was found in 0.77% of the examined Tubifex tubifex oligochaete specimens from a brook near Yamanashi Prefectural Fisheries Experimental Station on Fuji Mountain. In 0.14% of Lumbriculus variagetus collected from Chitose River, near Chitose Salmon Hatchery, a new siedleckiella type was found, while at the same time 8.1% of the Lumbriculus spp. oligochaetes released triactinomyxons of Myxobolus arcticus. Of the examined Rhyacodrilus komarovi oligochaetes collected from the Mena River system, Hokkaido, 0.2, 0.6, 0.5 and 0.8% were infected with echinactinomyxon, neoactinomyxum and 2 types of triactinomyxon spores, respectively, and described in our previous paper. The oligochaetes released actinospores for several weeks. Actinospore infection showed high intensity in positive oligochaetes in the case of all the actinosporean types. Two of the actinospore types (aurantiactinomyxon and siedleckiella) presented here have not been previously described.