taxonID	type	description	language	source
992987FDFF84FFE0FF83F9D106836F55.taxon	type_taxon	(type species: Unio caeruleus Lea, 1831; by original designation) (Prashad 1918).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE0FF83F9D106836F55.taxon	description	(Fig. 3 A – H)	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE0FF83F9D106836F55.taxon	discussion	Comments: This genus contains 12 accepted species. Based on our new phylogenetic and morphological data, we consider Indonaia corbis (Hanley, 1856) stat. rev. as an accepted species endemic to the Brahmaputra River basin (Table 1; Fig. 3 A – H). Additionally, two nominal species are transferred here from Indonaia to new genera (see below). Earlier, we separated three species groups in this genus: (i) the caerulea - group; (ii) the cylindrica - group; and (iii) the involuta - group (Bolotov et al. 2022 a). Indonaia corbis belongs to the first group that is well resolved in both COI - based and combined phylogenies (Fig. 2; Supporting Information, Fig. S 1). The cylindrica - group is supported by the COI phylogeny but is unresolved (non-monophyletic) in the three-locus combined tree. However, this group contains two Parreysia - like species that could be distinguished from other Indonaia species by having a thick, massive, ovate shell (Bolotov et al. 2022 a) and seems to be a pair of sister-species rather than two unrelated taxa. This issue needs to be checked in the future using an expanded set of DNA markers.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	type_taxon	(type species: Unio scobina Hanley, 1856).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	description	(Fig. 3 I – K) LSID: https: // zoobank. org / urn: lsid: zoobank. org: act: 6366 F 102 - F 465 - 4 FBD-BFF 2 - D 8 BF 8 FEE 87 C 7	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	diagnosis	Differential diagnosis: Phylogenetically, the new genus is the sister-lineage of Indonaia. However, it does not correspond to the latter genus by having a specific, strongly-developed sculpture over the shell disc, i. e. V- or W-shaped ridges at the middle of the shell, and waved and arcuate ridges at the anterior and posterior parts of the shell, respectively, while corresponding depressions display the same pattern in the inner side of the shell. Conchologically, the new genus is similar to the genera Harmandia Rochebrune, 1882 and Scabies Haas, 1911 (Indochinellini) but could be distinguished from these taxa by having a rectangular V- or W-shaped sculpture at the middle part of the shell. Furthermore, Indonaia rugosa (Gmelin, 1791) remotely resembles the new genus by having a few W-shaped ridges near the umbo but these ridges are less developed, less prominent, and do not spread over the dorsal half of the shell.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	description	Description: Shell thin, rather compressed; anterior margin broadly rounded; posterior margin slightly narrower, with small wing; dorsal margin slightly convex, its posterior part angular, umbo not prominent; ventral margin slightly convex. Umbo slightly shifted to the anterior part of the shell. Periostracum brown, sometimes with green markings on ridges at the posterior half of the shell. Nacre bluish white, sometimes with goldish spots. The shell is covered by peculiar sculpture: repeating V- or W-shaped ridges at the middle of the shell, surrounded by waved ridges at the anterior part of the shell and arcuate ridges at the posterior part of the shell. This sculpture is clearly visible in the inner side of the shell by depressions, the pattern of which corresponds to ridges on the outer side. Pseudocardinal teeth rather short, representing shallow, smooth ridges, two teeth in right valve and one tooth in left valve. Lateral teeth elongated, slightly curved, lamella-like, one tooth in right valve and two teeth in left valve. Anterior adductor muscle scar ovate, shallow; posterior adductor muscle scar ovate or round, very shallow, sometimes weakly visible.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	etymology	Etymology: The name of this genus comprises of two words: ‘ pseudo’ (translingual prefix, meaning ‘ appears like a true but is false’) and ‘ scabies’ [reference to the genus Scabies, in which it was placed due to a similar shell sculpture (Subba Rao 1989, Sonowal et al. 2021)].	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	distribution	Distribution: Endemic to the Brahmaputra River basin, north-eastern India.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	biology_ecology	Habitats: Topotypes of Pseudoscabies scobina gen. et comb. nov. (N = 8 specimens) were collected from the Sesa and Burhidihing rivers in Assam (Fig. 7 B). The species was found together with Parreysia marcens, Indonaia corbis, and Balwantia soleniformis.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF84FFE9FC99F97A042B68AA.taxon	discussion	Comments: Here, we transfer the nominal species Unio scobina Hanley from Indonaia to Pseudoscabies gen. nov. and propose P. scobina gen. et comb. nov.; its conchological form with broadly rounded V-shaped sculpture (e. g. see Fig. 3 K) was described as Unio radula Hanley, 1856 [= Nodularia (sec. Radiatula) lima Simpson, 1900].	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF36F8FE00936F5A.taxon	type_taxon	(type species: Unio involutus Hanley, 1856).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF36F8FE00936F5A.taxon	description	(Figs 6 A – C, 7 A) LSID: https: // zoobank. org / urn: lsid: zoobank. org: act: B 1 F 90 D 7 F- 3153 - 484 D- 8 FDC- 54 CCFD 0 E 3955 Differential diagnosis: From a phylogenetic perspective, the new genus is the sister-lineage of Parreysia but it could be distinguished from the latter genus by having a combination of the following characters: thin, fragile shell (vs. thick, massive), thin, lamella-like pseudocardinal teeth (vs. thick, massive, strongly indented), almost invisible adductor muscle scars (vs. deep, well visible). Among the Asian representatives of the subfamily, the new genus is more similar to Lamellidens but differs from it by having a much broader and larger umbo, longer and thinner pseudocardinal teeth, and the central position of umbo. Conchologically, the East African species Coelatura cridlandi Mandahl-Barth, 1954 (Coelaturini) that is endemic to Lake Victoria looks similar to the new genus but this external appearance most likely reflects convergent evolution. Description: Shell thin, very inflated; anterior margin broadly rounded; posterior margin triangular, with narrowly rounded apex; dorsal margin convex, dominated by massive, broad, very prominent umbo; ventral margin broadly convex. Umbo situated in the middle of the shell. Periostracum glossy, light green, usually with dirty yellow patches and bands of long growth lines. Pseudocardinal teeth elongated, narrow, thin, lamella-like, two teeth in right valve and one tooth in left valve. Lateral teeth elongated, lamella-like, one tooth in right valve and two teeth in left valve. Anterior and posterior adductor muscle scars almost invisible.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF36F8FE00936F5A.taxon	etymology	Etymology: The name of this genus is derived from two words: ‘ Assam’ (Indian state, in which it ranges) and ‘ naia ’ (a nymph in Latin, reference to the genus Indonaia, in which it was placed traditionally).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF36F8FE00936F5A.taxon	distribution	Distribution: Endemic to the Brahmaputra River basin in India and to the Surma River in Bangladesh.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF36F8FE00936F5A.taxon	biology_ecology	Habitats: Topotypes of Assamnaia involuta (Hanley, 1856) gen. et comb. nov. (N = 3 sequenced specimens and one dead shell) were collected from an oxbow lake of the Dhansiri River, close to the Kaziranga National Park in Assam (Fig. 7 A). This water body is connected with the main river channel during the rainy season. The mussels were sampled from silt and clay bottom substrate.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF36F8FE00936F5A.taxon	discussion	Comments: Here, we transfer the nominal species Unio involutus Hanley from Indonaia (the involuta - group) to Assamnaia gen. nov. and propose A. involuta gen. et comb. nov. The other member of the involuta - group, Indonaia olivaria (Lea, 1831) from the Ganges River, needs future study. In the absence of available DNA sequences, we prefer to consider it as an unassigned-togroup (incertae sedis) representative of the genus Indonaia.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF2EFE0C04BB6CB8.taxon	type_taxon	(type species: Anodonta soleniformis Benson, 1836; by original designation) (Prashad 1919).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF2EFE0C04BB6CB8.taxon	description	(Figs 4 A, 7 B, C)	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF2EFE0C04BB6CB8.taxon	diagnosis	Differential diagnosis: Balwantia is the sister-lineage of the genus Trapezidens but it cannot be placed in the latter genus due to a combination of specific morphological characters: ultra-elongated, narrow shell (vs. ovate or rhomboid, broad) and reduced pseudocardinal teeth (vs. well-developed, massive). Conchologically, Balwantia resembles other ultra-elongated genera of freshwater mussels such as Solenaia Conrad, 1869, Sinosolenaia Bolotov et al., 2021, Lanceolaria Conrad, 1853, Parvasolenaia Huang and Wu, 2019, and Koreosolenaia Lee et al., 2020. External similarity between these genera reflects convergent evolution and most of them cannot be distinguished based on conchological features alone (Bolotov et al. 2021). Balwantia differs from these genera by having unhooked glochidia and tetragenous brooding mode (Prashad 1919, Bolotov et al. 2022 a).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF2EFE0C04BB6CB8.taxon	discussion	Comments: The genus is monotypic and contains a single species having an ultra-elongated shell, B. soleniformis (Table 1; Fig. 4 A). Our new phylogenetic results support the morphology-based assumption that this genus belongs to the Parreysiinae due to the presence of unhooked glochidia and tetragenous brooding mode (Pfeiffer et al. 2021, Bolotov et al. 2022 a). We also show that it is a representative of the tribe Lamellidentini, whereas Balwantia was placed as incertae sedis Parreysiinae in our earlier revision (Bolotov et al. 2022 a).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF3BFA5804C66F81.taxon	type_taxon	(type species: Unio marginalis Lamarck, 1819; by original designation) (Simpson 1900).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF3BFA5804C66F81.taxon	description	(Figs 4 B – G, 5 A – G)	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE9FF3BFA5804C66F81.taxon	discussion	Comments: This genus contains 13 recent species (Bolotov et al. 2022 a, b). Two widespread and one putative local species were recorded from Assam (Table 1).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE8FC6EF97A04D26CBA.taxon	type_taxon	(type species: Unio multidentatus Philippi, 1847 [= Parreysia corrugata (O. F. Müller, 1774)]; by original designation) (Conrad 1853).	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE8FC6EF97A04D26CBA.taxon	description	(Fig. 6 D – I)	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
992987FDFF8DFFE8FC6EF97A04D26CBA.taxon	discussion	Comments: This genus contains eight recent species. Four nominal species belonging to the genus Parreysia were described from Assam: Unio favidens var. marcens Benson, 1862; Unio gowhattensis Theobald, 1873; Parreysia (Parreysia) annandalei Preston, 1912; and Parreysia favidens var. assamensis Preston, 1912 (Subba Rao 1989, Bolotov et al. 2022 a). These species were separated on the basis of minor morphological differences in shell shape (Benson 1862, Theobald 1873, Preston 1912). Our phylogenetic data reveal that there is a single Parreysia species in Assam (Supporting Information, Fig. S 1), the conchological varieties of which correspond to the four nominal species, listed above. Here, we consider Parreysia marcens (Benson, 1862) stat. rev. as an accepted species based on new DNA sequences and morphological data from Assam, while three other taxa described from this region are considered its synonyms (Table 1). This species has large genetic distance from its congeners (mean uncorrected COI p-distance of 7.3 – 8.3 %) (Supporting Information, Table S 1). Parreysia marcens belongs to the keralaensis - group of the genus, being a sister-lineage of Parreysia keralaensis Bolotov et al., 2022 a from south-western India. Our occurrence and sequence datasets indicate that Parreysia marcens is endemic to the Brahmaputra River basin and that this species inhabits a broad range of habitats (Supporting Information, Dataset S 1). This species was not recorded beyond the Brahmaputra Basin. Published records of other Parreysia species from Assam (Subba Rao 1989, Sonowal et al. 2021, Bolotov et al. 2022 a) should be considered as belonging to P. marcens. A published COI sequence of Parreysia from Nagaland (GenBank acc. No. OM 074301; Imsong and Murali 2023) that was erroneously identified as Parreysia corrugata (see: Bolotov et al. 2024) also belongs to Parreysia marcens (Table 1). This conclusion is based on the molecular genetic data (Supporting Information, Fig. S 1) and published image of the shell (Imsong and Murali 2023: fig. 1 G). Additionally, Parreysia smaragdites (Benson, 1862) is here considered a putative accepted species based on morphological features such as a rather thin shell and prominent, conical umbo (see: Preece et al. 2022: fig. 111 A). Comparative analysis of a syntype of P. smaragdites (UMZC I. 103360. A) (Preece et al. 2022) and the holotype of Unio corrugatus var. fragilis Hanley and Theobald, 1872 (NHMUK 1968651; unavailable name) from an unknown type locality indicates that these taxa are conspecific (Table 1). It is likely that the latter shell also originated from the Brahmaputra River basin. We were unable to find living specimens of P. smaragdites in Assam, and the identity of this interesting species needs to be checked by means of a DNA sequencing approach in the future.	en	Bolotov, Ivan N., Sonowal, Jyotish, Kardong, Devid, Pasupuleti, Rajeev, Subba Rao, Nalluri V., Unnikrishnan, Suresh Kumar, Gofarov, Mikhail Y., Kondakov, Alexander V., Konopleva, Ekaterina S., Lyubas, Artem A., Vikhrev, Ilya V. (2024): Discovery of an endemism hotspot of freshwater mussels (Bivalvia: Unionidae) in Assam, with a description of two new genera. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (4): 1-19, DOI: 10.1093/zoolinnean/zlae052, URL: https://doi.org/10.1093/zoolinnean/zlae052
