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| Moenkhausia solaris da Silva, de Santana & Marinho, 2025 |
Abstract
A new species of Moenkhausia is described from the headwaters of the Curuá and Teles Pires River basin, localities restricted to the Serra do Cachimbo, Pará, Brazil. The new species is diagnosed by the presence of dark blotches concentrated on the anterior portion of scales from the second to seventh longitudinal series, presence of red pigmentation on the adipose and caudal fins in life, green coloration in the ventral portion of the eye and absence of a longitudinal black stripe on body. The new species is morphologically similar and probably closely related to other Moenkhausia species endemic to the Brazilian Shield tributaries, particularly those restricted to the Serra do Cachimbo, sharing with them unique pigmentation traits. The ichthyofauna of the Serra do Cachimbo is notably distinct and characterized by high levels of endemism, likely influenced by geological barriers such as rapids and waterfalls that act as biogeographic barriers. The restricted and disjunct distribution of the new species in tributaries of Xingu and Tapajós basins suggests a historic headwater capture event in the Serra do Cachimbo plateau.
Keywords: Biogeography; Headwater capture; Moenkhausia clorophthalma; Tapajós; Xingu
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| Live specimens of Moenkhausia solaris, aquarium specimens, not preserved. Photo by Oliver Lucanus. |
Moenkhausia solaris, new species
Diagnosis. Moenkhausia solaris is distinguished from all congeners, except M. cambacica Marinho, Ohara & Dagosta, 2021, M. clorophthalma Sousa, Netto-Ferreira & Birindelli, 2010, M. lineomaculata Dagosta, Marinho & Benine, 2015, M. parecis Ohara & Marinho, 2016, M. petymbuaba Lima & Birindelli, 2006, and M. plumbea Sousa, Netto-Ferreira & Birindelli, 2010, by the presence of a dark blotch on the anterior portion of each scale of the second to seventh longitudinal series (vs. pigmentation absent or, when present, concentrated at the posterior margin of scales, forming a reticulate pattern). Moenkhausia solaris can be distinguished from all the aforementioned species, except M. petymbuaba, by having the adipose fin and the base of caudal-fin lobes red (vs. hyaline in M. lineomaculata and yellowish in ...
Etymology. The specific epithet solaris comes from Latin, meaning sunny or pertaining to the sun. In allusion to the bright gold color of body and red color of the adipose and caudal fin present in live specimens. An adjective.
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| One of the localities where Moenkhausia solaris was collected, MZUSP 128883, a small stream tributary of 13 de Maio River at the area of PCH Salto Três de Maio, upstream of the dam. |
José Igor da Silva, Yasmim de Santana and Manoela Maria Ferreira Marinho. 2025. A New Species of Moenkhausia (Characiformes: Acestrorhamphidae) from the Amazon basin at Serra do Cachimbo, Pará, Brazil. Neotrop. ichthyol. 23(03) DOI: doi.org/10.1590/1982-0224-2025-0089