Neotropical Ichthyology, 4(4):401-409, 2006 Copyright 2006 Sociedade Brasileira de Ictiologia
Redescription of Pterygoplichthys punctatus and description of a new species of Pterygoplichthys (Siluriformes: Loricariidae)
Jonathan W. Armbruster* and Lawrence M. Page**
Pterygoplichthys punctatus and P. weberi, new species, are unique among hypostomines in having a medially divided buccal papilla. The two species can be separated from one another by color (small spots in P. punctatus, large in P. weberi), condition of the buccal papilla (deeply divided at all ages in P. punctatus vs. shallowly divided in adults of P. weberi), condition of the lateral keel odontodes (fairly short and directed posteriorly in P. punctatus vs. large and directed almost laterally in P. weberi), and body width (SL/cleithral width 3.6-4.0 in P. punctatus vs. 3.3-3.4 in P. weberi). Pterygoplichthys punctatus is known from the rio Madeira drainage and the rio Urubu of Brazil and has published, but unconfirmed localities in the rio Purus and rio Tocantins basin, and P. weberi is known from the Río Maraon, Río Ucayali, and upper Río Amazonas drainages of Colombia, Ecuador, and Peru. Pterygoplichthys punctatus e P. weberi, espécie nova, so únicos entre os hipostomíneos por possuirem uma papila bucal dividida medialmente. As duas espécies podem ser separadas entre si pela colorao (pequenos pontos em P. punctatus, pontos grandes em P. weberi), condio da papila bucal (profundamente dividida em jovens e adultos de P. punctatus vs. dividida superficialmente em adultos de P. weberi), condio da quilha de odontódios laterais (pequena e dirigida posteriormente em P. punctatus vs. grande e dirigida quase lateralmente em P. weberi), e largura do corpo (comprimento padro/largura no cleitro 3.6-4.0 em P. punctatus vs. 3.3-3.4 em P. weberi). Pterygoplichthys punctatus é conhecida da drenagem do rio Madeira e do rio Urubu no Brasil and tem sido citada, porém sem confirmao, para localidades nas bacias dos rio Purus e Tocantins, e P. weberi é conhecida do río Maraon, río Ucayali, e drenagens do alto río Amazonas na Colmbia, Ecuador e Peru. Key words: Hypostominae, Systematics, Pterygoplichthyini, suckermouth armored catfishes Introduction With about 80 genera and over 700 species, Loricariidae is the largest family of catfishes (Siluriformes). Loricariids are endemic to South America (absent in Chile), Panama, and Costa Rica and are characterized by having large bony plates and a ventral suctorial mouth with or without noticeable barbels. A group of loricariid catfishes with 10 or more dorsal-fin rays is commonly referred to as sailfin catfishes. Weber (1991, 1992) reviewed variation among sailfin catfishes and assigned them to three genera. Species with an elevated supraoccipital process were placed in Glyptoperichthys Weber, 1991, those lacking the elevated supraoccipital process and with the supraoccipital bone bordered posteriorly by one large plate were assigned to Pterygoplichthys Gill, 1858, and those lacking the elevated supraoccipital process and with the supraoccipital bone bordered posteriorly by three plates were assigned to Liposarcus Günther, 1864. Armbruster (2004) noted that the synapomorphies provided by Weber (1991, 1992) were inadequate to diagnose three genera, and that neither Pterygoplichthys nor Glyptoperichthys could be recovered as monophyletic. He placed Liposarcus and Glyptoperichthys in the synonymy of Pterygoplichthys and recognized the tribe Pterygoplichthyini (originally misspelled as Pterygoplichthini) for Pterygoplichthys and an undescribed genus (the Hemiancistrus annectens group of Armbruster, 1998) from the transAndean region. Pterygoplichthyini was diagnosed by an increased number of plates between the opercle and the suprapreopercle (two or three vs. zero or one) and the presence of a large, respiratory stomach attached to the dorsal wall of the abdominal cavity via a sheet of connective tissue. Pterygoplichthys cannot be diagnosed by any unique synapomorphies; however, Armbruster (2004) listed several homoplasic synapomorphies: the presence of more than seven dorsal-fin rays, no or a diminutive interopercle that is on the

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