After Aquino & Schaefer, 2002, Britski & Garavello, 2003, and Armbruster, 2004, with Recent species from Froese & Pauly, 2001 [“The FishBase”]

<==o Hypoptopomatinae
   |-- Schizolecis guntheri (Miranda-Ribeiro, 1918)
   `--+--o Parotocinclus (vasamamonnit)
      |  |-- P. amazonensis Garavello, 1976
      |  |-- P. aripuanensis Garavello, 1988
      |  |-- P. bahiensis (Miranda-Ribeiro, 1918)
      |  |-- P. britskii Boeseman, 1974
      |  |-- P. cearensis Garavello, 1976
      |  |-- P. cesarpintoi Miranda-Ribeiro, 1939
      |  |-- P. collinsae Schmidt & Ferraris, 1985
      |  |-- P. cristatus Garavello, 1976
      |  |-- P. doceanus (Miranda-Ribeiro, 1918)
      |  |-- P. eppleyi Schaefer & Provenzano R., 1993
      |  |-- P. haroldoi Garavello, 1988
      |  |-- P. jimi Garavello, 1976
      |  |-- P. jumbo Britski & Garavello, 2002 (Pit Bull Pleco; katinkultamonni)
      |  |-- P. longirostris Garavello, 1988
      |  |-- P. maculicauda (Steindachner, 1877) [Otocinclus maculicauda Steindachner, 1877]
      |  |-- P. minutus Garavello, 1976
      |  |-- P. polyochrus Schaefer, 1988
      |  |-- P. spilosoma (Fowler, 1941)
      |  `-- P. spilurus (Fowler, 1941)
      `--+--o Otothyrini
         |  |?-o Corumbataia Britski, 1997
         |  |  |-- C. britskii Ferreira & Ribeiro, 2007
         |  |  |-- C. cuestae Britski, 1997
         |  |  |-- C. tocantinensis Britski, 1997
         |  |  `-- C. veadeiros Carvalho, 2008
         |  |--o Otothyris Myers, 1927
         |  |  |-- O. juquiae Garavello, Britski & Schaefer, 1998
         |  |  |-- O. lophophanes (Eigenmann & Eigenmann, 1889) [Rhinelepis lophophanes Eigenmann & Eigenmann, 1889, non Otothyris lophophanes (Miranda Ribeiro, 1911)] [incl. Otocinclus cephaloacanthus Miranda Ribeiro, 1911]; Otothyris canaliferus Myers, 1927]
         |  |  |-- O. rostrata Garavello, Britski & Schaefer, 1998
         |  |  `-- O. travassosi Garavello, Britski & Schaefer, 1998
         |  `-- Hisonotus Eigenmann & Eigenmann, 1889 [Otocinclus Cope; Microlepidogaster]
         `--+--o Otocinclus Cope (nuoli-imumonnit) [includes some species later referred to Hisonotus]
            |  |-- O. bororo Schaefer, 1997
            |  |-- O. caxarari Schaefer, 1997
            |  |-- O. hasemani Steindachner, 1915
            |  |-- O. hoppei Miranda-Ribeiro, 1939
            |  |-- O. huaorani Schaefer, 1997
            |  |-- O. macrospilus Eigenmann & Allen, 1942
            |  |-- O. mariae Fowler, 1940
            |  |-- O. mura Schaefer, 1997
            |  |-- O. vestitus Cope, 1872
            |  |-- O. vittatus Regan, 1904
            |  `-- O. xakriaba Schaefer, 1997
            `--+--o Pseudotothyris
               |  |-- P. janeirensis Britski & Garavello, 1984
               |  `-- P. obtusa (Miranda-Ribeiro, 1911) [Otocinclus obtusus Miranda-Ribeiro, 1911]
               `--+-- Niobichthys ferrarisi Schaefer & Provenzano R., 1998
                  `--+--o Acestridium Haseman, 1911
                     |  |-- A. discus Haseman, 1911
                     |  |-- A. dichromum Retzer, Nico & Provenzano, 1999
                     |  |-- A. martini Retzer, Nico & Provenzano, 1999
                     |  |-- A. colombiensis Retzer, 2005
                     |  |-- A. triplax Rodriguez & Reis, 2007
                     |  |-- A. gymnogaster Reis & Lehmann A., 2009
                     |  `-- A. scutatum Reis & Lehmann A., 2009
                     `--+--o Oxyropsis Eigenmann and Eigenmann, 1889 [Hypoptopoma Günther, 1868] [3]
                        |  |-- O. acutirostris Miranda-Ribeiro, 1951
                        |  |-- O. wrightiana Eigenmann & Eigenmann, 1889
                        |  `-- O. carinata (Steindachner, 1879) [Hypoptopoma carinatum Steindachner, 1879]
                        `--+--o Nannoptopoma
                           |  |-- N. spectabile (Eigenmann, 1914) [Otocinclus spectabilis Eigenmann, 1914]
                           |  `-- N. sternoptychum Schaefer, 1996
                           `--o Hypoptopoma Günther, 1868
                              |-- H. bilobatum Cope, 1870
                              |-- H. guentheri Boulenger, 1895
                              |-- H. guianense Boeseman, 1974
                              |-- H. gulare Cope, 1878
                              |-- H. inexspectatum (Holmberg, 1893)
                              |-- H. joberti (Vaillant, 1880) [Otocinclus joberti Vaillant, 1880]
                              |-- H. psilogaster Fowler, 1915
                              |-- H. steindachneri Boulenger, 1895
                              `-- H. thoracatum Günther, 1868

Phygenetically untreated Hypoptopomatines

    Eurycheilichthys Reis & Schaefer, 1993
        E. limulus Reis & Schaefer, 1998
        E. pantherinus (Reis & Schaefer, 1992)
    Epactionotus
        E. bilineatus Reis & Schaefer, 1998
        E. gracilis Reis & Schaefer, 1998
        E. itaimbezinho Reis & Schaefer, 1998
    Lampiella
        L. gibbosa (Miranda Ribeiro, 1908) [Otocinclus gibbosus Miranda Ribeiro, 1908]
    Macrotocinclus
        M. affinis (Steindachner, 1877) [Otocinclus affinis Steindachner, 1877] (vihernuoli-imumonni; Golden otocinclus)
        M. flexilis (Cope, 1894) [Otocinclus flexilis Cope, 1894] [incl. Otocinclus fimbriatus Cope, 1894; Otocinclus arnoldi Regan, 1909]
    Microlepidogaster [includes some species later referred to Hisonotus]
        M. bourguyi Miranda-Ribeiro, 1911
        M. laevior (Cope, 1894)
        M. leptochilus (Cope, 1894)
        M. maculipinnis (Regan, 1912)
        M. perforatus Eigenmann & Eigenmann, 1889
        M. taimensis Buckup, 1981

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