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Two new species of miniature tetras of the fish genus Priocharax from the Rio Juruá drainage, Acre, Brazil (Teleostei: Characiformes: Characidae)

Publication: Canadian Journal of Zoology
10 February 2023


Two new miniature tetra species of the Neotropical characid genus Priocharax Weitzman and Vari, 1987 are described, raising the known species diversity to seven. Both species occur in the Rio Juruá system, Cruzeiro do Sul municipality, Acre State, Brazil. Priocharax toledopizae sp. nov. occurs in streams flowing to the lower Rio Moa, a tributary of Rio Juruá, and is distinguished from congeners by a combination of presence of claustrum and infraorbitals 1 and 2, absence of infraorbital 3, and presence of five branched pelvic-fin rays. Priocharax marupiara sp. nov. is known from Igarapé Canela Fina, tributary of Rio Juruá, and is diagnosed by a combination of fewer maxillary teeth (21–27 vs. 27–58 in remaining species), fewer branched anal-fin rays (18–23 vs. 22–27 in two species) and colour pattern. Both species differ from each other in the general body shape: Priocharax toledopizae is more robust with deep body and Priocharax marupiara more elongate. DNA barcode data support the specific distinctness of the two new species and that of the other five species in the genus. We describe a remarkable sexual dimorphism of the pelvic girdle of Priocharax toledopizae in which the pelvic musculature is enlarged forming a pedicel for the fin in mature males. Most localities where these species were found suffer from significant degradation mainly due to litter accumulation and suppression of the riparian forest, raising concerns about their conservation status.

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Abrahão V.P, Pastana M., Marinho M. 2019. On a remarkable sexual dimorphic trait in the Characiformes related to the olfactory organ and description of a new miniature species of Tyttobrycon Géry (Characiformes: Characidae). PLoS ONE, 14(12): e0226130.
Britz R., Conway K.W. 2009. Osteology of Paedocypris, a miniature and highly developmentally truncated fish (Teleostei: Ostariophysi: Cyprinidae). J. Morphol. 270: 389–412.
Britz R., Conway K.W. 2016. Danionella dracula, an escape from the cypriniform Bauplan via developmental truncation? J. Morphol. 277: 147–166.
Britz R., Conway K.W., Rüber L. 2009. Spectacular morphological novelty in a miniature cyprinid fish, Danionella dracula n. sp. Proc. R. Soc. B 276: 2179–2186.
Camelier P., Zanata A.M. 2014. A new species of Astyanax Baird & Girard (Characiformes: Characidae) from the Rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil, with comments on bony hooks on all fins. J. Fish Biol. 84(2): 475–490.
Conway K.W., Britz R. 2007. Sexual dimorphism of the Weberian apparatus and pectoral girdle in Sundadanio axelrodi (Ostariophysi: Cyprinidae). J. Fish. Biol. 71(5): 1562–1570.
Edgar R.C. 2004. MUSCLE: a multiple sequence alignment method with reduced time and space complexity. BMC Bioinform. 5(1): 1–19.
Fink W.L., Weitzman S.H. 1974. The so-called cheirodontin fishes of Central America with descriptions of two new species (Pisces: Characidae). Smithsonian Contrib. Zool. 172: 1–46.
Hammer O., Harper D.A.T., Ryan P.D. 2001. PAST: Paleontological Statistics software package for education and data analysis. Palaeontol. Electron. 4(1): 9.
Hanken J., Wake D.B. 1993. Miniaturization of body size: organismal consequences and evolutionary significance. Annu. Rev. Ecol. Syst. 24: 501–519.
Ivanova N.V., Dewaard J.R., Hebert P.D. 2006. An inexpensive, automation-friendly protocol for recovering high-quality DNA.Mol. Ecol. Notes, 6(4): 998–1002.
Jacó T.R.F., Silva R.S., Silva H.C., Virgílio L.R., Lima F.C.T., Casas A.L.S. 2020. Ictiofauna do Igarapé Preto, Cruzeiro do Sul – Acre, Brasil. In Biodiversidade e Biotecnologia no Brasil 1. Organized by M. Silveira, E. Silva, R.A. Lima. Stricto Sensu Editora, Rio Branco. pp. 31–49.
Jennings W.B., Ruschi P.A., Ferraro G., Quijada C.C., Silva-Malanski A.C.G., Prosdocimi F., Buckup P.A. 2019. Barcoding the neotropical freshwater fish fauna using a new pair of universal COI primers with a discussion of primer dimers and M13 primer tails. Genome, 62(2): 7–83.
Kearse M., Moir R., Wilson A., Stones-Havas S., Cheung M., Sturrock S., et al. 2012. Geneious Basic: an integrated and extendable desktop software platform for the organization and analysis of sequence data. Bioinformatics, 28: 647–1649.
Manly B.F.J. 2008. Métodos Estatísticos Multivariados – uma introdução. 3rd ed. Bookman, Porto Alegre. pp. 229.
Mattox G.M.T., Britz R., Toledo-Piza M. 2014. Skeletal development and ossification sequence of the characiform Salminus brasiliensis (Teleostei: Ostariophysi: Characidae). Ichthyol. Explor. Freshw. 25(2): 103–158.
Mattox G.M.T., Britz R., Toledo-Piza M. 2016. Osteology of Priocharax and remarkable developmental truncation in a miniature Amazonian fish (Teleostei: Characiformes: Characidae). J. Morphol. 277(1): 65–85.
Mattox G.M.T., Souza C.S., Toledo-Piza M., Britz R., Oliveira C. 2020. A new miniature species of Priocharax (Teleostei: Characiformes: Characidae) from the Rio Madeira drainage, Brazil, with comments on the adipose fin in characiforms. Vertebr. Zool. 70(3): 417–433.
Mattox G.M.T., Souza C.S., Toledo-Piza M., Oliveira C. 2021. A new miniature species of Priocharax (Characiformes: Characidae) from the upper rio Ipixuna, Purus drainage, Brazil. Neotrop. Ichthyol. 19: e210048.
Mattox G.M.T., Kubicek K.M., Britz R. 2022. Notes on the skeletal anatomy of Priocharax ariel Weitzman & Vari, 1987 with implications for its taxonomy (Teleostei: Characiformes). Zootaxa, 5138(5): 597–599.
Melo B.F., Benine R.C., Mariguela T.C., Oliveira C. 2011. A new species of Tetragonopterus Cuvier, 1816 (Characiformes: Characidae: Tetragonopterinae) from the rio Jari Amapá, northern Brazil. Neotrop. Ichthyol. 9: 49–56.
Menezes N.A., Weitzman S.H. 1990. Two new species of Mimagoniates (Teleostei: Characidae: Glandulocaudinae), their phylogeny and biogeography and a key to the glandulocaudin fishes of Brazil and Paraguay. Proc. Biol. Soc. Wash. 103(2): 380–426.
Papa Y., Le Bail P.Y., Covain R. 2021. Genetic landscape clustering of a large DNA barcoding data set reveals shared patterns of genetic divergence among freshwater fishes of the Maroni Basin. Mol. Ecol. Resour. 21(6): 2109–2124.
Parenti L.R. 1984. On the relationships of the phallostethid fishes (Atherinomorpha), with notes on the anatomy of Phallostethus dunckeri Regan, 1913. Am. Mus. Novit. 2779: 1–12. Available from  [accessed 29 January 2023].
Parenti L.R. 1989. A phylogenetic revision of the phallostethid fishes (Atherinomorpha, Phallostethidae). Proc. Cal. Acad. Sci. 46:243–277.
Roberts T.R. 1966. Description and osteology of Lepidarchus adonis, a remarkable new characid fish from West Africa. Stanford Ichthyol. Bull. 8(3): 209–227.
Stamatakis A. 2014. RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics, 30(9): 1312–1313.
Tamura K., Stecher G., Kumar S. 2021. MEGA11: molecular evolutionary genetics analysis version 11. Mol. Biol. Evol. 38(7): 3022–3027.
Taylor W.R., Van Dyke G.C. 1985. Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9(2): 107–109. Available from  [accessed 29 January 2023].
Toledo-Piza M., Mattox G.M.T., Britz R. 2014. Priocharax nanus, a new miniature characid from the rio Negro, Amazon basin (Ostariophysi: Characiformes), with an updated list of miniature neotropical freshwater fishes. Neotrop. Ichthyol. 12(2): 229–246.
Vieira C.S., Bartolette R., Brito M.F.G. 2016. Comparative morphology of bony hooks of the anal and pelvic fin in six neotropical characid fishes (Ostariophysi: Characiformes). Zool. Anz. 260: 57–62.
Ward R.D., Zemlak T.S., Innes B.H., Last P.R., Hebert P.D. 2005. DNA barcoding Australia’s fish species. Philos. Trans. R. Soc. B Biol. Sci. 360(1462): 1847–1857.
Weitzman S.H. 1962. The osteology of Brycon meeki, a generalized characid fish, with an osteological definition of the family. Stanford Ichthyol. Bull. 8(1): 1–77.
Weitzman S.H., Fink S.V. 1985. Xenurobryconin phylogeny and putative pheromone pumps in Glandulocaudine fishes. Smithsonian Contrib. Zool. 421: 1–121p. Available from   [accessed 29 January 2023].
Weitzman S.H., Vari R.P. 1987. Two new species and a new genus of miniature characid fishes (Teleostei: Characiformes) from Northern South America. Proc. Biol. Soc. Wash. 100(3): 640–652.
Weitzman S.H., Vari R.P. 1988. Miniaturization in South American freshwater fishes: an overview and discussion. Proc. Biol. Soc. Wash. 101(2): 444–465.
Xia X. 2013. DAMBE5: a comprehensive software package for data analysis in molecular biology and evolution. Mol. Biol. Evol. 30(7): 1720–1728.
Xia X., Xie Z., Salemi M., Chen L., Wang Y. 2003. An index of substitution saturation and its application. Mol. Phylogenet. Evol. 26(1): 1–07.
Zarske A. 2010. Der Kolibrisalmler Trochilocharax ornatus gen. et spec. nov. – eine neuer Salmler aus Peru (Teleostei: Characiformes: Characidae). Vertebr. Zool. 60(2): 75–98.
Zhang J., Kapli P., Pavlidis P., Stamatakis A. 2013. A general species delimitation method with applications to phylogenetic placements. Bioinformatics, 29(22): 2869–2876.

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Published In

cover image Canadian Journal of Zoology
Canadian Journal of Zoology
Volume 101Number 4April 2023
Pages: 248 - 266


Received: 16 September 2022
Accepted: 23 November 2022
Version of record online: 10 February 2023

Data Availability Statement

Data generated or analyzed during this study are provided in full within the published article and its supplementary materials, and are also available from the corresponding author upon reasonable request.  Molecular data generated or analyzed during this study are available in the GenBank at


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Key Words

  1. anatomy
  2. DNA barcode
  3. Neotropics
  4. integrative taxonomy
  5. miniature tetra
  6. systematics



Laboratório de Ictiologia de Sorocaba, Departamento de Biologia, Universidade Federal de São Carlos, Sorocaba, São Paulo 18052-780, Brazil
Author Contributions: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Writing – original draft, and Writing – review & editing.
Ralf Britz
Senckenberg Natural History Collections Dresden, Museum of Zoology, Dresden, 01109, Germany
Author Contributions: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Supervision, Writing – original draft, and Writing – review & editing.
Camila S. Souza
Departamento de Biologia Estrutural e Funcional, Instituto de Biociências, Universidade Estadual Paulista – Campus Botucatu, Botucatu, São Paulo 18618-689, Brazil
Author Contributions: Data curation, Formal analysis, Investigation, Methodology, Resources, Software, Validation, Writing – original draft, and Writing – review & editing.
André L.S. Casas
Departamento de Ciências do Mar, Instituto do Mar, Universidade Federal de São Paulo, Santos, São Paulo 11015-020, Brazil
Author Contributions: Data curation, Investigation, Writing – original draft, and Writing – review & editing.
Flávio C.T. Lima
Museu de Diversidade Biológica, Universidade Estadual de Campinas, Caixa Postal 6109, Campinas, São Paulo 13083-683, Brazil
Author Contributions: Data curation, Funding acquisition, Investigation, Writing – original draft, and Writing – review & editing.
Claudio Oliveira
Departamento de Biologia Estrutural e Funcional, Instituto de Biociências, Universidade Estadual Paulista – Campus Botucatu, Botucatu, São Paulo 18618-689, Brazil
Author Contributions: Data curation, Funding acquisition, Project administration, Resources, Supervision, Writing – original draft, and Writing – review & editing.

Author Contributions

Conceptualization: GMTM, RB
Data curation: GMTM, RB, CSS, ALSC, FCTL, CO
Formal analysis: GMTM, RB, CSS
Funding acquisition: GMTM, FCTL, CO
Investigation: GMTM, RB, CSS, ALSC, FCTL
Methodology: GMTM, RB, CSS
Project administration: GMTM, CO
Resources: GMTM, CSS, CO
Software: GMTM, CSS
Supervision: GMTM, RB, CO
Validation: CSS
Writing – original draft: GMTM, RB, CSS, ALSC, FCTL, CO
Writing – review & editing: GMTM, RB, CSS, ALSC, FCTL, CO

Competing Interests

The authors declare there are no competing interests.

Funding Information

This research was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; grant 2017/01970-4). FCTL was supported by FAPESP (grants 2011/51532-7 and 2013/20936-0). CO received financial support from FAPESP (grant 2020/13433-6) and Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq (proc. 306054/2006-0).

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