Updated 7 April 2024
PDF version (with illustrations and additional information)

Lowland Pacus
Subfamily COLOSSOMATINAE Kolmann, Hughes, Hernandez, Arcila, Betancur-R, Sabaj Pérez, López-Fernández & Ortí 2021

Colossoma Eigenmann & Kennedy 1903 colos, from chólos (Gr. χόλος), gall or bile, but authors say “without horns”; sṓma (Gr. σῶμα), body, referring to lack of “procumbent predorsal spine” as present on many serrasalmids

Colossoma macropomum (Cuvier 1816) macro-, from makrós (Gr. μακρός), long or large; pṓma (Gr. πῶμα), lid or cover, i.e., operculum (but apparently treated as an adjective by Cuvier), referring to its large, wide operculum

Mylossoma Eigenmann & Kennedy 1903 mylo-, from mýlos (Gr. μύλος), mill (i.e., millstone); sṓma (Gr. σῶμα), body, referring to disk-like body shape

Mylossoma acanthogaster (Valenciennes 1850) acanthus (L.), from ákantha (Gr. ἄκανθα), thorn; gastḗr (Gr. γαστήρ), belly or stomach, referring to its serrate ventral keel

Mylossoma albiscopum (Cope 1872) albus (L.), white; skopós (Gr. σκοπός), looker, contemplator or viewer (i.e., eye), allusion not explained nor evident [name historically treated as an adjective]

Mylossoma aureum (Spix & Agassiz 1829) Latin for golden, referring to its coloration

Mylossoma duriventre (Cuvier 1818) durus (L.), hard or tough; ventre, genitive of venter (L.), belly, probably referring to spiny serrae on ventral keel

Mylossoma unimaculatum (Steindachner 1908) uni-, from unus (L.), one; maculatum (L.), spotted, referring to a “deep, round, sharply demarcated spot a short distance above the lateral line and in the vertical direction, slightly behind the beginning of the dorsal” (translation); modern accounts and photographs do not mention nor show this spot, but do report a conspicuous black or brown blotch on opercle

Piaractus Eigenmann 1903 pī́ar (Gr. πῖαρ), fat; aktís (Gr. ἀκτίς), ray, referring to rayed adipose fin

Piaractus brachypomus (Cuvier 1818) brachýs (Gr. βραχύς), short; pṓma (Gr. πῶμα), lid or cover, i.e., operculum (but apparently treated as an adjective by Cuvier), referring to shorter operculum compared with Colossoma macropomum

Piaractus mesopotamicus (Holmberg 1887) -icus (L.), belonging to: mésos (Gr. μέσος), middle or in between; potamós (Gr. ποταμός), river, allusion not explained but almost certainly referring to Región Mesopotámica (or La Mesopotamia), the northeast region of Argentina located between the rivers Paraná and Uruguay, where this species occurs

Piaractus orinoquensis Escobar L., Ota, Machado-Allison, Andrade-López, Farias & Hrbek 2019 -ensis, Latin suffix denoting place: Orinoquia or Llanos Orientales, geographic area of Colombia where it occurs

---

Upland Pacus
Subfamily MYLEINAE Eigenmann 1903

Acnodon Eigenmann 1903 ἀ-, Greek privative, i.e., without; knṓdōn (Gr. κνώδων), projecting teeth on the blade of a hunting spear, presumably based on the false impression that A. oligacanthus lacks a predorsal spine (it is small and easily overlooked)

Acnodon normani Gosline 1951 in honor of English ichthyologist J. R. (John Roxborough) Norman (1898–1944), British Museum (Natural History), for his “excellent work” on serrasalmids as well as other fish groups

Acnodon oligacanthus (Müller & Troschel 1844) olígos (ὀλίγος), little, small or few; acanthus (L.), from ákantha (Gr. ἄκανθα), thorn, referring to small (and easily overlooked) predorsal spine

Acnodon senai Jégu & Santos 1990 in memory of Brazilian fisheries worker Anazildo Mateus de Sena, Instituto Nacional de Pesquisas da Amazônia (Manaus), who collected holotype during one of his last trips to the field in June 1987

Mylesinus Valenciennes 1850 –inus (L.), adjectival suffix, i.e., Myleus-like, referring to similarity to that genus

Mylesinus paraschomburgkii Jégu, Santos & Ferreira 1989 pará (Gr. παρά), near, referring to previous misidentification as M. schomburgkii

Mylesinus paucisquamatus Jégu & Santos 1988 paucus (L.), few; squamatus (L.), scaled, referring to fewer lateral-line scales compared with other myleinine fishes

Mylesinus schomburgkii Valenciennes 1850 in honor of German explorer Robert Hermann Schomburgk (1804–1865), who illustrated the specimen upon which the description is based (holotype is a head)

Myleus Müller & Troschel 1844 Neo-Latin scientific adjective of mýlos (Gr. μύλος), mill, i.e., like a millstone, presumably referring to disk-like shape of M. setiger

Myleus altipinnis (Valenciennes 1850) altus (L.), high; pinnis, Neo-Latin adjective of pinna (L.), fin, i.e., finned, referring to its long posterior dorsal-fin rays, longer than those on Tometes unilobatus (=T. trilobatus)

Myleus knerii (Steindachner 1881) patronym not identified but almost certainly in honor of Steindachner’s Austrian friend and colleague, ichthyologist Rudolf Kner (1810–1869), who described several serrasalmid fishes

Myleus micans (Lütken 1875) Latin for twinkling, allusion not explained, perhaps referring to silvery iridescent markings on sides

Myleus pachyodus Andrade, Jégu, Buckup & Netto-Ferreira 2018 pachýs (Gr.παχύς), thick or stout; odus, from odoús (Gr. ὀδούς), tooth, referring to teeth of adults, which are much thicker when compared with the flat, incisiform teeth of congeners

Myleus pacu (Jardine 1841) a “provincial name” for several species in Guyana, including this one, derived from the Tupí word pa’ku [Species inquirenda, provisionally included here]

Myleus planquettei (Jégu, Keith & Le Bail 2003) in honor of French Guianan ichthyologist Paul Planquette (1940–1996), Institut National de la Recherche Agronomique (Kourou), for his work studying the fishes of French Guiana

Myleus setiger Müller & Troschel 1844 seta or saeta (L.), hair or bristle; –iger (L.), to have or bear, allusion not explained, probably referring to filamentous first dorsal-fin rays seen in this species (and other Myleus and Myloplus)

Myloplus Gill 1896 proposed as a subgenus of Myletes (a suppressed name in the synonymy of Alestes, Alestidae), etymology not explained, perhaps Mylo-, referring to similarly disk-shaped serrasalmids with the same generic prefix, and plus (L.), more, i.e., an additional Myleus-like taxon

Mylophus animacula Soares, Andrade & Lucinda 2023 ani (L.), genitive singular of anus); macula, stain or mark, referring to conspicuous black mark at tip of anteriormost branched anal-fin rays

Myloplus arnoldi Ahl 1936 in honor of German aquarist Johann Paul Arnold (1869–1952), who donated specimens to the Zoological Museum of Berlin

Myloplus asterias (Müller & Troschel 1844) asterías (Gr. ἀστερίας), a starred or starry fish or bird, allusion not explained, presumably referring to round, orange-colored spots on body

Myloplus levis (Eigenmann & McAtee 1907) Latin for smooth, polished or bald, allusion not explained nor evident

Myloplus lobatus (Valenciennes 1850) Latin for lobed, referring to anterior rays of anal fin forming a rounded lobe

Myloplus lucienae Andrade, Ota, Bastos & Jégu 2016 in honor of Luciene Maria Kassar Borges, for her “pioneer attempt” (a 1986 Ph.D. disseration) to organize what is known about herbivorous Serrasalmidae from the Rio Negro basin

Myloplus nigrolineatus Ota, Machado, Andrade, Collins, Farias & Hrbek 2020 nigro-, from niger (L.), dark or black; lineatus (L.), lined, referring to dark chromatophores on lateral-line scales, giving the appearance of a black lateral line

Myloplus rubripinnis (Müller & Troschel 1844) rubrum (L.), red; pinnis, Neo-Latin adjective of pinna (L.), fin, i.e., finned, referring to distinctive red-hooked anal fin on adult males

Myloplus schomburgkii (Jardine 1841) in honor of German explorer Robert Hermann Schomburgk (1804–1865), who provided notes and illustration upon which description is based (no types known)

Myloplus tiete (Eigenmann & Norris 1900) etymology not explained, probably referring to Tieté River system (São Paulo, Brazil), which includes Piracicaba River, type locality

Myloplus torquatus (Kner 1858) Latin for collared or adorned with a necklace, referring to black vertical streak or band behind head over pectoral fin

Myloplus tumukumak Andrade, Jégu & Gama 2018 named for the Tumuk-Humak Mountain Range, where type locality (Oyapock River and its tributaries between Brazil and French Guiana) is situated

Myloplus zorroi Andrade, Jégu & Giarrizzo 2016 in honor of Mauricio Camargo-Zorro, a researcher at the Instituto Federal de Educação, Ciência e Tecnologia (São Paulo), for his “invaluable” contribution to the fish fauna inventory from the Marmelos Conservation Area (boundaries of Amazonas and Rondônia states, Brazil, where this species occurs); name also alludes to the Latin-American fictional character “Zorro,” which was the secret identity of Don Diego de la Vega, because its features “masked” it as Tometes, concealing its true identity

Ossubtus Jégu 1992 os (L.), mouth; subtus (L.), below, referring to strictly ventral position of mouth, unique in the family

Ossubtus xinguense Jégu 1992 -ense, Latin suffix denoting place: Rio Xingu, Altamira, Pará, Brazil, type locality

Paramyloplus Norman 1929 pará (Gr. παρά), near, similar to Myloplus but lacking conical maxillary teeth

Paramyloplus taphorni (Andrade, López-Fernández & Liverpool 2019) in honor of American ichthyologist Donald C. Taphorn (b. 1951), for “over four decades of continuing contributions to Neotropical ichthyology, his expansive role in training South American ichthyologists (including the authors), and for his participation in the expedition” during which holotype was collected

Paramyloplus ternetzi Norman 1929 in honor of Swiss-born ichthyologist and naturalist Carl Ternetz (1870–1928), who made extensive collections in French Guiana for the British Museum (including, presumably, holotype of this species)

Prosomyleus Géry 1972 prósō (Gr. πρόσω), in front, proposed as a subgenus of Myleus with upper anterior medial teeth implanted anteriorly, forming the branches of a “V”

Prosomyleus rhomboidalis (Cuvier 1818) –alis (L.), adjectival suffix, presumably referring to its rhomboid-like body shape

Tometes Valenciennes 1850 presumably from tómos (Gr. τόμος), cutter or knife (i.e., one who cuts), referring to obliquely beveled incisors of T. trilobatus; according to Valenciennes, name was coined in the same way that Cuvier (1814) coined Myletes (now a synonym of Alestes but at the time including both alestids and serrasalmids) for characiform fishes with molariform (grinding) teeth, from mýlos (Gr. μύλος), mill (i.e., millstone)

Tometes ancylorhynchus Andrade & Giarrizzo 2016 curve-snouted, from ankýlos (Gr. ἀγκύλος), bent, curved or bowed, and rhýnchos (Gr. ῥύγχος), snout, referring to its relatively short and curved snout, resembling the curved beak of a parrot

Tometes camunani Andrade, Giarrizzo & Jégu 2013 vernacular for this species among the Wai-Wai, who inhabit the upper rio Trombetas basin (Pará State, Brazil) and consider this species of great cultural importance; name is also used by local quilombolas (inhabitants of settlements founded by escaped slaves of African origin), who capture the fish using the fruit of the camu-camu tree (Myrciaria dubia, Myrtaceae) as bait

Tometes kranponhah Andrade & Giarrizzo 2016 named for the indigenous Pytako tribe inhabiting the banks of the Xingu River basin (Brazil), who know this fish as kranponhah, meaning long-haired (kran, head; ponhah, hair or hairy), referring to the long dorsal-fin filaments of mature males

Tometes lebaili Jégu, Keith & Belmont-Jégu 2002 in honor of French ichthyologist Pierre-Yves Le Bail (b. 1954), Institut National de la Recherche Agronomique (Rennes, France), for research and revisionary studies of the fishes of French Guiana, including the first collection of this species

Tometes makue Jégu, Santos & Belmont-Jégu 2002 from makue ñigi, local Tukano (also spelled Tucano) name for this species in Brazil, meaning “black pacu”

Tometes siderocarajensis Andrade, Machado, Jégu, Farias & Giarrizzo 2017 –ensis, Latin suffix denoting place: Serra dos Carajás, the largest high-grade iron deposit in the world (from sídēros [Gr. σίδηρος] iron), Tocantins-Araguaia River basin, Pará, Brazil, type locality

Tometes trilobatus Valenciennes 1850 tri– (L.), three; lobatus (L.), lobed, presumably referring to anal-fin lobe formed by its middle (three?) rays

Utiaritichthys Miranda Ribeiro 1937 Utiarity, referring to Salto Utiarity, or Utiarity Falls, Mato Grosso, Brazil, type locality of U. sennaebragai; ichthýs (Gr. ἰχθύς), fish

Utiaritichthys esguiceroi Pereira & Castro 2014 in honor of Brazilian ichthyologist André L. H. Esguícero (b. 1980), University of São Paulo, who collected holotype

Utiaritichthys longidorsalis Jégu, Tito de Morais & Santos 1992 longus (L.), long; dorsalis (L.), of the back, referring to longer dorsal-fin base compared with U. sennaebragai

Utiaritichthys sennaebragai Miranda Ribeiro 1937 in honor of Colonel Senna Braga, Commander of the 5º Militar Grupamento de Engenharia (equivalent to the U.S. Army Corps of Engineers), who helped Miranda Ribeiro obtain types when he visited Salto Utiarity (or Utiarity Falls, type locality) in May 1909

---

Piranhas
Subfamily SERRASALMINAE Bleeker 1859

Catoprion Müller & Troschel 1844 cato-, from katá (Gr. κατά), beneath, below or under; príōn (Gr. πρίων), saw, probably referring to saw-toothed ventral keel on C. mento

Catoprion absconditus Mateussi, Melo & Oliveira 2020 Latin for hidden or concealed, having been identified as C. mento for 201 years, ever since that species was described in 1819

Catoprion mento (Cuvier 1819) from mentum (L.), chin, referring to its jutting lower jaw

Metynnis Cope 1878 etymology not explained, possibly metá (Gr. μετά), with, and hýnnis (Gr. ὕννις), plowshare (main cutting blade of a plow), perhaps referring to serrate abdominal keel or belly of M. luna, “armed with spiniferous ? interhæmal bones” (question mark in original, significance not evident, perhaps a lapsus), or to “cultriform” (knife-shaped) predorsal bone or spine at base of dorsal fin, a character Cope used to distinguish the genus from Myletes (now divided between Colossoma, Mylossoma and Piaractus)

Metynnis altidorsalis Ahl 1923 altus (L.), high; dorsalis (L.), of the back, allusion not explained, perhaps referring to its extended dorsal-fin rays and/or high dorsal profile

Metynnis anisurus Ahl 1923 unequally-tailed, from ánisos (Gr. ἄνισος), unequal, and urus, from ourá (Gr. οὐρά), tail, referring to upper caudal-fin lobe smaller than lower lobe

Metynnis argenteus Ahl 1923 Latin for silvery, referring to its shiny silver color in alcohol

Metynnis cuiaba Pavanelli, Ota & Petry 2009 named for the Rio Cuiabá, Rio Paraguai basin, Mato Grosso, Brazil, type locality

Metynnis fasciatus Ahl 1931 Latin for banded, referring to 3–4 bluish bars on sides

Metynnis guaporensis Eigenmann 1915 –ensis, Latin suffix denoting place: Rio Guaporé at Maciél, Brazil, type locality

Metynnis hypsauchen (Müller & Troschel 1844) hypso-, from hypsēlós (Gr. ὑψηλός), high; auchḗn (Gr. αὐχήν), nape, referring to its high dorsal profile

Metynnis lippincottianus (Cope 1870) –ianus (L.), belonging to: Cope’s friend James S. Lippincott (1819–1885), “author of important contributions to Meteorology, Agriculture and other subjects”

Metynnis longipinnis Zarske & Géry 2008 longus (L.), long; pinnis, Neo-Latin adjective of pinna (L.), fin, i.e., finned, referring to its extremely elongated dorsal and anal fins

Metynnis luna Cope 1878 Latin for moon, presumably referring to its “orbicular” shape

Metynnis maculatus (Kner 1858) Latin for spotted, referring to rounded dark spots on body and/or large black humeral spot

Metynnis melanogrammus Ota, Rapp Py-Daniel & Jégu 2016 dark-lined, from mélas (Gr. μέλας), black or dark, and grammḗ (Gr. γραμμή), line or stroke of the pen, referring to well-marked dark lateral line

Metynnis mola Eigenmann & Kennedy 1903 Latin for millstone, referring to its “nearly circular” form

Metynnis orinocensis (Steindachner 1908) –ensis, Latin suffix denoting place: Orinoco River basin, Venezuela, where it is endemic

Metynnis otuquensis Ahl 1923 –ensis, Latin suffix denoting place: Río Otuquis, Paraguay, type locality

Metynnis polystictus Zarske & Géry 2008 polý (Gr. πολύ), many; stictus, from stiktós (Gr. στικτός), spotted, referring to numerous small spots on body

Pygocentrus Müller & Troschel 1844 pygo-, from pygḗ (Gr. πυγή), rump; centrus, from kéntron (Gr. κέντρον), prickle, referring to serrate abdomen

Pygocentrus cariba (Humboldt 1821) local Venezuelan equivalent of the Brazilian word piranha

Pygocentrus nattereri Kner 1858 in honor of Austrian naturalist Johann Natterer (1787–1843), who explored South America and collected specimens for 18 years, including some males of this species

Pygocentrus piraya (Cuvier 1819) along with piranha, one of the local names for serrasalmid fishes in Brazil

Pygopristis Müller & Troschel 1844 pygo-, from pygḗ (Gr. πυγή), rump; pristis, from príō (Gr. πρίω) or prízō (πρίζω), to saw, or from prístēs (πρίστης), sawyer, referring to serrated spines on abdomen

Pygopristis denticulata (Cuvier 1819) Latin for having small teeth (denticulate), referring to its narrower, less-oblique teeth compared with other serrasalmids Cuvier had examined

Serrasalmus Lacepède 1803 serra (L.), saw, referring to serrate ventral keel; salmus, from salmo (L.), salmon, referring to salmon-like adipose fin

Serrasalmus altispinis Merckx, Jégu & Santos 2000 altus (L.), high; spinus, from spina (L.), thorn, referring to “deeper” serrae compared with S. rhombeus

Serrasalmus altuvei Ramírez 1965 in honor of sylviculturist and forestry expert Néstor Altuve, Director of Natural Resources of the Agriculture Ministry in Venezuela, where type locality (El Polvero, Río San José, Guárico) is situated

Serrasalmus aureus Spix & Agassiz 1829 Latin for golden, referring to olive and “shining gold” (translation) coloration

Serrasalmus auriventris (Burmeister 1861) aureus (L.), golden; ventris, genitive of venter (L.), belly, referring to its golden-yellow belly [Species inquirenda, provisionally included here]

Serrasalmus brandtii Lütken 1875 patronym not identified, possibly in honor of German naturalist, surgeon and pharmacologist Johann Friedrich von Brandt (1802–1879)

Serrasalmus calmoni Steindachner 1908 patronym not identified but based on information in Steindachner’s 1907 description of the loricariid catfish Pareiorhaphis cameroni (a lapsus for calmoni), probably in honor of Miguel Calmon du Pin e Almedia (1879–1935), Brazil’s Minister of Agriculture, Commerce and Industry, as a “token of my respect and gratitude” (translation)

Serrasalmus careospinus (Fink & Machado-Allison 1992) careo (L.), without; spinus, from spina (L.), thorn, referring to lack of pre-anal spine

Serrasalmus compressus Jégu, Leão & Santos 1991 Latin for squeezed together, referring to its deep and compressed body

Serrasalmus eigenmanni Norman 1929 in honor of German-born American ichthyologist Carl H. Eigenmann (1863–1927), for his work on characid fishes

Serrasalmus elongatus Kner 1858 Latin for prolonged, referring to its relatively elongate body, the most elongate species of piranha

Serrasalmus geryi Jégu & Santos 1988 in honor of French physician and ichthyologist Jacques Géry (1917–2007), for his “important” (translation) work among serrasalmids and Serrasalmus in particular

Serrasalmus gibbus Castelnau 1855 Latin for hump or humpback, referring to “curved back of the head” (translation)

Serrasalmus gouldingi Fink & Machado-Allison 1992 in honor of conservation ecologist Michael Goulding (b. 1950), for his “indefatigable efforts” in collecting Amazonian fishes and understanding the ecosystem in which they live, helping the senior author in the field, and for sharing his first-hand knowledge of Amazonian piranhas

Serrasalmus hastatus Fink & Machado-Allison 2001 Latin for armed with a spear (authors say “spear-shaped”), referring to its pointed and highly compressed snout

Serrasalmus hollandi Eigenmann 1915 in honor of Jamaican-born American zoologist-paleontologist William J. Holland (1848–1932), Director of the Carnegie Museum, which published many of Eigenmann’s papers

Serrasalmus humeralis Valenciennes 1850 Latin for humeral, referring to its large, blackish humeral spot

Serrasalmus irritans Peters 1877 Latin for bothersome or irritating, allusion not explained, possibly referring to a piranha’s teeth, voracious feeding behavior and fearsome (though greatly exaggerated) reputation (although Peters noted that this species is less-aggressive than Pygocentrus nattereri)

Serrasalmus maculatus Kner 1858 Latin for spotted, referring to rounded blackish spots on body

Serrasalmus maculipinnis (Fink & Machado-Allison 1992) maculatus (L.), spotted; pinnis, Neo-Latin adjective of pinna (L.), fin, i.e., finned, referring to extensive spotting of vertical fins, a rare pattern in serrasalmids

Serrasalmus magallanesi Gallo-Cardozo, Maldonado, Careaga & Carvajal-Vallejos 2024  in memory of Frank Magallanes (d. 2022), for his “permanent collaboration with ichthyologists and Serrasalmus fans, mainly through his website” Oregon Piranha Exotic Fish Exhibit (opefe.com)

Serrasalmus manueli (Fernández-Yépez & Ramírez 1967) in honor of Manuel, the second author’s son, who died early, and who since early childhood had accompanied the authors on their “memorable” (translation) fishing expeditions

Serrasalmus marginatus Valenciennes 1837 Latin for bordered, referring to its black-edged anal fin

Serrasalmus medinai Ramírez 1965 in honor of Gonzalo Medina, chief of the Division of Fauna, Natural Resources, Ministry of Agriculture and Animal Husbandry, Venezuela, where type locality (El Polvero, Río San José, Guárico) is situated

Serrasalmus nalseni Fernández-Yépez 1969 in honor of Bo Jaime Nalsen (b. 1939), who helped collect holotype while working at the fish research station of Venezuela’s Oficina Nacional de Pesca

Serrasalmus neveriensis Machado-Allison, Fink, López Rojas & Rodenas 1993 –ensis, Latin suffix denoting place: Río Neveri, Querechual, Estado Anzoálegui, Venezuela, type locality

Serrasalmus nigricans Spix & Agassiz 1829 Latin for blackish, referring to body coloration

Serrasalmus nigricauda (Burmeister 1861) nigra-, from niger (L.), dark or black; cauda (L.), tail, referring to broad black band at beginning of tail [species inquirienda, provisionally included here]

Serrasalmus odyssei Hubert & Renno 2010 Bolivian name “applied to the locally known piranha ‘suave’ and referring to the taxonomic confusion with this species at the beginning of the fieldwork during the present study”

Serrasalmus rhombeus (Linnaeus 1766) Latin for rhombic, probably referring to the rhomboid shape of adults

Serrasalmus sanchezi Géry 1964 in honor of Peruvian fisheries biologist Jorge Sanchez Romero

Serrasalmus scapularis Günther 1864 Latin for scapular or of the shoulder, presumably referring to large blackish blotch behind gill opening

Serrasalmus serrulatus (Valenciennes 1850) diminutive of serra (L.), saw, i.e., small saw-toothed, referring to its “clearly serrate” abdomen

Serrasalmus spilopleura Kner 1858 spílos (Gr. σπίλος), mark or spot; pleurá (Gr. πλευρά), side, referring to numerous black spots on sides of juvenile specimens