microstomus, Hypostomus Weber [C.] 1987:275, Figs. 2-3, 7a [Archives des Sciences (Geneva) v. 40 (no. 3); ref. 6241] Río Alta-Paraná, Río Paraná system, 15 kilometers southeast of Encarnacion, Campichuelo, 27°26'S, 55°45'W, Paraguay. Holotype: MHNG 2367.90. Paratypes: MHNG 2367.91-92 (4, 1). Type catalog: Weber 1998:9 [ref. 32707], Ferraris 2007:257 [ref. 29155]. •Valid as Watawata microstomus (Weber 1987) -- (Isbrücker et al. 2001:22 [ref. 25649], Isbrücker 2001:28, 32 [ref. 25653], Isbrücker 2002:30 [ref. 27178], López et al. 2003:52 [ref. 27366], Menni 2004:81 [ref. 28131]). •Valid as Hypostomus microstomus Weber 1987 -- (López & Miquelarena 1991:36 [ref. 23548], Gómez & Chebez 1996:64 [ref. 23791], Weber in Reis et al. 2003:360 [ref. 27061], Armbruster 2004:79 [ref. 27644], Ferraris 2007:257 [ref. 29155], Zawadzki et al. 2010:724 [ref. 31074], Koerber 2011:5 [ref. 31122], Cardoso et al. 2012:77 [ref. 32154], Zawadzki et al. 2014:103 [ref. 33233], Martins et al. 2014:7 [ref. 33617], Koerber 2014:9 [ref. 33621], Litz & Koerber 2014:25 [ref. 33622], Mirande & Koerber 2015:43 [ref. 35117], Cardoso et al. 2016:22 [ref. 34373], Nión et al. 2016:32 [ref. 35565] with author in parentheses, Koerber et al. 2017:62 [ref. 35267], Zawadzki et al. 2017:12 [ref. 35355], Zawadzki et al. 2018:[16] [ref. 35944], Zawadzki et al. 2019:[11] [ref. 37170], Reis et al. 2020:467 [ref. 38364], Azevedo et al. 2021:9 [ref. 38203], Zawadzki et al. 2021:110 [ref. 38157]). Current status: Valid as Hypostomus microstomus Weber 1987. Loricariidae: Hypostominae. Distribution: South America: Paraná River system, Paraguay River basin (Argentina, Paraguay and Uruguay). Habitat: freshwater.