taxonID	type	description	language	source
658ED4EB06D756158B50EE0725B38ECB.taxon	type_taxon	Type species. Guiunio rarus Chen, Li, Dai & Wu, sp. nov.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
658ED4EB06D756158B50EE0725B38ECB.taxon	diagnosis	Diagnosis. Shell medium-sized, moderately thick, flat, long, sub-glossy, opaque. Anterior small, rounded and short; posterior extremely expanded, wide and long, with an indistinct obtuse angle in the middle of posterior margin. Umbo inflated, slightly higher at the hinge line, located at 1 / 4 of the dorsal margin, with concentric square carving. Periostracum yellowish green to brown with thin growth lines. Papillae on flap margin highly degraded.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
658ED4EB06D756158B50EE0725B38ECB.taxon	description	Description. Shell medium-sized, moderately thick, flat, long, sub-glossy, opaque. Anterior small, rounded and short; posterior extremely expanded, wide and long, with an indistinct obtuse angle in the middle of posterior margin. Dorsal margin slightly curved downwards and truncated in behind; ventral margin weakly curved or retuse. Umbo inflated, slightly higher the hinge line, located at 1 / 4 of the dorsal margin, with concentric square carving. Periostracum yellowish green to brown with thin growth lines. Posterior slope with an indistinct low secondary posterior ridge end in the angle on the posterior margin. Growth lines arranged in irregular concentric circles. Hinge long. Ligament short and strong. Beak cavities shallow, open. Mantle attachment scars on the pallial line obvious. Anterior adductor muscle scars irregularly oval, deep, smooth; posterior adductor muscle scars long oval, smooth. Left valve with two pseudocardinal teeth, posterior tooth elevated pyramidal or degenerated; anterior tooth thick and pyramidal. Right valve also with one pseudocardinal tooth, low triangular. Lateral teeth of both valves long and thin. Nacre light orange to white. Mantle light brown, aperture margins black, papillae on flap margin highly degraded. Gills light brown, inner gills slightly longer and wider than outer gills. Labial palpsrown, distally pointed and irregularly fan-shaped in appearance. Visceral mass grayish white, foot light orange.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
658ED4EB06D756158B50EE0725B38ECB.taxon	etymology	Etymology. The species is made from the Gui for the abbreviation for Guangxi and unio for the unionid type genus.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
5484ED9AA328596B996E7D6BECDE71E8.taxon	description	Fig. 2	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
5484ED9AA328596B996E7D6BECDE71E8.taxon	diagnosis	Diagnosis. Same as the genus.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
5484ED9AA328596B996E7D6BECDE71E8.taxon	description	Description. Same as the genus.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
5484ED9AA328596B996E7D6BECDE71E8.taxon	description	Measurements. Holotype: shell length 50.0 mm, height 29.4 mm, width 14.2 mm. Paratypes: shell length 32.2 – 72.3 mm, height 18.1 – 42.2 mm, width 7.8 – 26.2 mm.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
5484ED9AA328596B996E7D6BECDE71E8.taxon	etymology	Etymology. The species is named after Latin rarus for rare, referring to the rarity of it.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
5484ED9AA328596B996E7D6BECDE71E8.taxon	distribution	Distribution and ecology. Known from the type locality only (Fig. 3). Living in the slow flowing stream with muddy and sandy bottom alongside Cristaria plicata (Leach, 1814), Nodularia douglasiae (Gray, 1833) and Lanceolaria gladiola (Heude, 1877). In addition, the new species was associated with a yet-to-be-described species of Rhodeus Agassiz, 1832, which may be laying eggs in the gills of it (all type specimens of the new species were collected during the dry season in winter, so no fish eggs were observed in the gills). It is an occasional species in the type locality, accounting for less than 1 / 20 of the population of all freshwater mussels.	en	Dai, Yu-Ting, Chen, Zhong-Guang, Li, Fan, Huang, Xiao-Chen, Ouyang, Shan, Wu, Xiao-Ping (2025): A new genus and species of freshwater mussel from the Pearl River Basin in Guangxi, China (Bivalvia, Unionidae, Gonideinae). Zoosystematics and Evolution 101 (2): 805-812, DOI: 10.3897/zse.101.151802
