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Issue: Vol. 5537 No. 2: 8 Nov. 2024
Type: Article
Published: 2024-11-08
DOI: 10.11646/zootaxa.5537.2.5
Page range: 245-258
Abstract views: 388
PDF downloaded: 11

Schizodon unimaculatus, a new species from the lower Rio São Francisco with a reappraisal of the Schizodon species presenting a caudal-peduncle blotch (Teleostei: Anostomidae)

Departamento de Ecologia e Biologia Evolutiva; Universidade Federal de São Carlos; Rod. Washington Luís; km 235; 13565-905; São Carlos; SP; Brazil
Seção de Peixes; Museu de Zoologia; Universidade de São Paulo; Av. Nazaré; 481; 04218-970; São Paulo; SP; Brazil
Departamento de Ciências Ambientais; Universidade Federal de São Carlos; Rod. Washington Luís; km 235; 13565-905; São Carlos; SP; Brazil
Department of Ichthyology; American Museum of Natural History; 200 Central Park West; New York; NY 10024; USA
Pisces Anostomoidea Characiformes morphometrics Ostariophysi taxonomy

Abstract

Schizodon unimaculatus new species, is described from the lower sections of the Rio São Francisco in northeastern Brazil. The new species differs from all known Schizodon species by the combination of presenting a subinferior mouth, a prominent dark brown blotch on the caudal peduncle, a dark brown longitudinal stripe along the lateral line, and three series of small dark dots horizontally aligned forming interrupted lines on the dorsal and middle regions of the trunk. It differs from congeners with a horizontal stripe and a dark blotch on the caudal peduncle, viz., S. knerii, S. rostratus, S. jacuiensis, S. nasutus, S. isognathus, S. altoparanae, S. vittatus, and S. trivittatus, by the combination of scale counts in lateral line and around caudal peduncle, color pattern, mouth position, and body proportions. The subinferior mouth additionally distinguishes the new species from S. knerii, S. jacuiensis, S. nasutus, S. altoparanae, S. platae, S. isognathus, and S. rostratus. Principal component and canonical variation analyses additionally distinguish the new species from S. knerii, S. altoparanae, and S. nasutus. We discuss the taxonomic history, relationships, and significance of mouth morphology, coloration, and meristic characters in taxonomic studies of Schizodon.

 

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