taxonID	type	description	language	source
03F50F68FFAFFFF8F0C1353687709932.taxon	materials_examined	Type species: Chaetonotus hystrix Metschnikoff, 1865; designation by Schwank (1990) The subgenus Hystricochaetonotus was established by Schwank (1990) for the Chaetonotus species previously included in the ‘ group’ spinulosus by Remane (1936). The subgenus has been subsequently accepted by Kisielewski (1997) in its revision of the subgeneric division of the genus Chaetonotus. The diagnostic features of the subgenus are: a cuticular covering made of three-lobed scales with thick spines, a varying number of which form a dorsal group that can be generally recognized for the considerable length. However, the great intraspecific morphological variability of most species, and the existence of species with intermediate features and thus difficult to be clearly assigned to this subgenus rather than to the subgenus C haetonotus s. s., make this character not reliable for diagnostic purpose, even for the type-species (C. hystrix). It seems that there is a continuum of the morphological characters putatively fixing the distinction between the subgenera Hystricochaetonotus and C haetonotus s. s., which seem actually to form a single natural group. Thus Chaetonotus (Hystricochaetonotus) is synonimized with Chaetonotus (Chaetonotus s. s.) (syn. nov.) and all the species currently included into it are moved to the latter:	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFACFFF8F0C13760824D9C56.taxon	diagnosis	Diagnosis. Chaetonotus of body length 60 – 370 µm. Scales one- to three-lobed with at least one, clear, axial keel. Well developed spines arising from the posterior edge of scales. Spines short to very long, without or with 1 (occasionally 2) accessory points. Some spines greatly longer than the others can be present dorsally on the trunk or dorsolaterally at the furcal base. An area covered with scales bearing a short or very short spine or even with no spine is often present dorsally on the posteriormost trunk region. Ventral field cuticular covering different in scale distribution and usually also in scale shape from that of the dorsal body surface. Posterior and often anterior pharynx thickenings marked. Freshwater, brackish-water and marine. Benthic, interstitial and periphytic.	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFACFFF9F0C1350A87289E20.taxon	description	The genus Lepidochaetus was introduced by Kisielewski (1991) to group some freshwater species previously included in the genus Chaetonotus, characterized by numerous, rounded, unkeeled scales, provided with long and thin spines covering both the dorsal and the ventral body surfaces. According to Kisielewski’s (1991, 1997) phylogenetic views, this cuticular morphology would be plesiomorphic in the Chaetonotida. Other more complex morphological patterns would have arisen from this one, generally different on the dorsal and on the ventral body surfaces, as it is the usual condition in the species of genus Chaetonotus. The latter is a very large genus which includes both freshwater and marine species: Remane (1936) had already divided the genus on morphological criteria into 9 ‘ groups’, to only two of which he recognized a subgeneric rank [C. (Zonochaeta) and the marine C. (Halichaetonotus)]. In his systematic revision of the freshwater species, Schwank (1990) divided the genus Chaetonotus into 8 subgenera (including [C. (Zonochaeta)], all but one, [C. (Nudichaetonotus)] corresponding to the Remane’s groups. A new subgeneric division of the whole genus Chaetonotus was then introduced by Kisielewski (1997), who recognized 8 subgenera, accepting those previously created by Schwank except for two [C. (Bifasciculatella) and C. (Diversichaetatella)] and introducing three others: C. (Primochaetus), C. (Captochaetus) and C. (Marinochaetus), the last one entirely marine. However, the main morphological features diagnostic of the genus Lepidochaetus (large kephalion with a free caudal edge, round-rectangular scales with double anterior edge, some dorsal and lateral rear scales with long, straight spines, ventral cuticular covering agreeing in number and character of structures with the dorsal and lateral ones) cannot be unambiguously distinguished from those of the genus Chaetonotus to which most species of Lepidochaetus were previously assigned. For this reason Lepidochaetus should no longer be considered as a separate genus but rather as a subgenus of Chaetonotus (syn. nov.). Five species were originally included in this genus: L. brasilense Kisielewski, 1991, L. carpaticus (Rudescu, 1967); L. ornatus (Daday, 1901), L. pusillus (Daday, 1905), L. zelinkai (Grünspan, 1908). When moved into Chaetonotus, Lepidochaetus brasilense Kisielewski, 1991 becomes Chaetonotus brasilensis, a secondary junior homonym of Chaetonotus brasiliensis Schwank, 1990. We propose here the new name Chaetonotus brasilianus (nomen novum), as a replacement name for Lepidochaetus brasilense Kisielewski, 1991 nec Schwank, 1990. L. pusillus (Daday, 1905) has been successively moved by Kisielewski (1997) into the subgenus Chaetonotus s. s. and thus is now Chaetonotus (C.) pusillus (Daday, 1905). The other 3 species are thus retained in Chaetonotus (Lepidochaetus), as Chaetonotus (L.) carpaticus (Rudescu, 1967), Chaetonotus (L.) ornatus (Daday, 1901), and Chaetonotus (L.) zelinkai (Grünspan, 1908). Because of the change from a generic to a subgeneric rank within the genus Chaetonotus, the original diagnosis of Lepidochaetus (Kisielewski, 1991, p. 10) is emended as follows:	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFADFFF9F0C1367A80B19C9F.taxon	materials_examined	Type species: Lepidochaetus brasilense Kisielewski, 1991; original typus generis of the genus Lepidochaetus, here designated as the type-species of the subgenus Chaetonotus (Lepidochaetus).	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFADFFF9F0C1367A80B19C9F.taxon	diagnosis	Diagnosis: Chaetonotus of body length 166 – 311 µm. Large kephalion extended on the dorsal head surface. Well developed furcal adhesive tubes. Rounded scales with an anterior ridge. Well developed spines arising from the posterior edge of scales. Thin spines short to very long, without or with 1 accessory point. At the posterior trunk region some lateral and dorsal spines notably long, the rearmost ones extending beyond the furcal tubes. Ventral field cuticular covering similar in scale distribution and also in scale shape to that of the dorsal body surface. Exclusively freshwater, benthic, and periphytic.	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFAAFFFEF0C131C781CB9F4F.taxon	description	Typus generis: Chaetonotus larus (Müller, 1773); original designation. Emended diagnosis: Chaetonotinae with body 60 – 625 µm long. Cephalic plates (kephalion, epipleuria, hypopleuria) usually present, and often well developed. Hypostomion occasionally present. Furcal adhesive tubes occasionally very short. Dorsal cuticular covering of numerous scales arranged in longitudinal rows and provided with well developed spines. Rounded, one-lobed or three-lobed scales with an anterior ridge or an axial keel, in some cases with three radial keels. Spines very short up to very long, without or with 1 (occasionally 2) accessory point. Some spines greatly longer than the others can be present dorsally on the trunk or dorsolaterally at the furcal base. An area with scales with short or very short spines or even without spines is often present dorsally on the posteriormost trunk region. Dorsal and ventral interciliary cuticular coverings similar to or different in scale distribution and shape. Posterior and often anterior pharynx thickenings are sometimes present. Freshwater, brackish-water and marine. Benthic, interstitial and periphytic.	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFAAFFFFF0C1360081E19B7E.taxon	description	Typus generis: Ichthydium podura (Müller, 1773); designation by Ehrenberg, 1830 Subgenus Ichthydium (Ichthydium sensu stricto) Ehrenberg, 1830 [Hummon, 2008 b] [syn. Euichthydium Schwank, 1990]	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFAAFFFFF0C1360081E19B7E.taxon	materials_examined	Type species: Ichthydium podura (Müller, 1773); original designation by Schwank, 1990 Subgenus Ichthydium (Forficulichthys) Schwank, 1990 Type species: Ichthydium (Forficulichthys) forficula (Remane, 1927); original designation by Schwank, 1990 Subgenus Ichthydium (Pseudichthydium) Rudescu, 1967 Type species: Ichthydium (Pseudichthydium) balatonicum (Varga, 1950); original designation by Schwank, 1990: 102 The genus Ichthydium is clearly considered as polyphyletic and thus it is an artificial taxon (Kisielewski, 1991). It needs a careful taxonomic revision rather than a division into subgenera based on very few morphological criteria, like the different shape of the furcal tubes and the possible presence of thin dorsal scales on the bare body cuticle. The latter feature is not peculiar of the subgenus I. (Forficulichthys), since cuticular microsculptures and thin scales are occasionally present also in species of the subgenus I. (Ichthydium s. s.), i. e. I. podura, I. squamigerum. The diagnostic characters of the rare monotypic subgenus Ichthydium (Pseudichthydium) appear so different from the other Ichthydium species that they would require a closer examination of the only species known. For all this reasons the subgenera introduced by Schwank (1990) have not been introduced in the present list.	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFABFFFFF0C1321682599F66.taxon	description	Typus generis: Lepidoderma punctatum Greuter, 1917; original designation by Schwank (1990) as Rhomballichthys punctatus. Schwank (1990) introduced the genus Rhomballichthys for three freshwater species with a complete cuticular covering of rhombic, unpedunculated scales, smooth or keeled, and with a very short, minute spiny process. These features combine those of three different genera (Aspidiophorus, Lepidodermella, Heterolepidoderma). Scale shape and habitus of the species remind the species of Aspidiophorus, which all have pedunculated scales. On the other hand, the Lepidodermella species have smooth scales and the Heterolepidoderma species have numerous, small, elliptical, generally keeled, unpedunculated scales. The typus generis of Rhomballichthys, R. punctatus (Greuter, 1917) is a species whose taxonomical position has been long debated: it was assigned to either Aspidiophorus or Lepidodermella and it was finally place into the latter genus due to the presence of unpedunculated, smooth scales, even if provided with a very short spiny extension (Balsamo 1983). Rhomballichthys murrayi is a new name introduced by Schwank (1990) for Chaetonotus sp. Murray, 1913: the original description of this species is quite incomplete and does not allow to define with certainty its morphological characters, so that it is a species inquirenda. Finally, Rhomballichthys carinatus is a new name introduced by Schwank (1990) for the specimens of Heterolepidoderma fallax Remane, 1936 reported by Roszczak (1969) from Poland. Schwank considered these ones as belonging to a different species from Heterolepidoderma fallax Remane, 1936, that he includes among the species inquirendae. The assignment of the Polish specimens to a new species should require a careful revision of the distinctive characters: Rhomballichthys carinatus is considered here as a species inquirenda. The genus Rhomballichthys is maintained as a monotypic genus only including R. punctatus (Greuter, 1917).	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
03F50F68FFABFFFCF0C1354F82DE9986.taxon	materials_examined	Type species: Dasydytes (Setopus) tongiorgii Balsamo, 1982; designation by Schwank (1990) According to Schwank (1990, p. 42) the genus Dasydytes includes 3 subgenera: D. (Dasydytes s. s.), D. (Setodytes) and D. (Setopus). Schwank established the subgenus Dasydytes (Setodytes) in order to distinguish Dasydytes (S.) tongiorgii, D. (S.) chatticus and D. (s.) lemnicola (nomen nudum) from the rest of the species in the subgenus D. (Setopus), because provided with spines with an accessory point. The former two species show also two peculiar caudal spines of different length and with an accessory point. However, both the spines with an accessory point and the unequal caudal spines are characters present in other species of Dasydytidae, and do not appear to be diagnostic at subgeneric level. Thus, the subgenus Dasydytes (Setodytes) is synonymized with the genus Setopus (syn. nov.), a taxon which has to be considered at a generic level, according to the original description by Grünspan (1908) and the emended diagnosis by Kisielewski (1991). The freshwater genus Dasydytes counts now two subgenera (Dasydytes sensu stricto, Prodasydytes). Chaetonotida Paucitubulatina currently include 7 families (Chaetonotidae, Dasydytidae, Dichaeturidae, Muselliferidae, Neogosseidae, Proichthydidae, Xenotrichulidae) and 28 genera. Four families (Dasydytidae, Dichaeturidae, Neogosseidae, Proichthydidae), with 12 genera, are exclusively freshwater. Chaetonotidae are composed of 12 genera, 5 of which are only freshwater (Arenotus, Fluxiderma, Polymerurus, Romballichthys and Undula), 5 have both freshwater and marine species (Aspidiophorus, Chaetonotus, Heterolepidoderma, Ichthydium, Lepidodermella), and 2 are exclusively marine (Caudichthydium, Halichaetonotus). Muselliferidae, with 2 genera (Diuronotus, Musellifer) and Xenotrichulidae, with 3 genera (Draculiciteria, Heteroxenotrichula, Xenotrichula) comprise exclusively marine species. The complete list of the world freshwater species of Gastrotricha currently considered as reliable species, and indicated with the updated taxonomic name, is given in the Appendix, also including the only two species incertae sedis of Macrodasyida which have been found in fresh waters. For completeness also the species inquirendae, the species incertae sedis and the nomina nuda are reported, and the updated numbers of the reliable species (both freshwater and marine) of each genus and subgenus is given. This checklist is a part of a complete dataset of freshwater species of Gastrotricha of the world, which includes taxonomical comments and geographical distribution at biogeographical region and / or at country / State level of each species, as well as a list of the bibliographic references. This dataset, nearing completion, w i l l b e p u b l i s h e d a n d m a d e f r e e l y a c c e s s i b l e a t t h e w e b s i t e o f FA D A p r o j e c t [h t t p: / / www. fada. biodiversity. be].	en	Balsamo, Maria, Pierboni, Lara, Grilli, Paolo (2009): Taxonomic and nomenclatural notes on freshwater Gastrotricha. Zootaxa 2158: 1-19, DOI: 10.5281/zenodo.275059
