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| Aspidoras aldebaran Tencatt, Britto, Isbrücker & Pavanelli, 2022 Photos by Hans Evers. |
Abstract
Aspidoras comprises 25 species currently considered as valid, being widely distributed in Brazil, occurring from the upper rio Paraná basin in São Paulo to coastal basins of Ceará. After Nijssen, Isbrücker’s review more than 40 years ago, no extensive work regarding the taxonomy of Aspidoras was conducted. Our paper presents a comprehensive taxonomic revision of the genus, based primarily on the extensive material that has been collected since then. Considering the new diagnosis plus the available phylogenetic data, A. pauciradiatus and A. virgulatus are transferred to Corydoras and Scleromystax, respectively. New synonymies are proposed: A. eurycephalus and A. taurus with A. albater; A. menezesi and A. spilotus with A. raimundi; and A. microgalaeus and A. marianae with A. poecilus. Additionally, a new species from the Araguaia and Paraguay river basins is described, which can be distinguished from its congeners by the morphology of its complex vertebra and infraorbital 1. Thereby, the number of valid species within Aspidoras was reduced from 25 to 18. Redescriptions for A. albater, A. belenos, A. depinnai, A. fuscoguttatus, A. lakoi, A. maculosus, A. poecilus, A. psammatides, A. raimundi, and A. velites are provided. An identification key to the species of Aspidoras is also provided.
Keywords: Aspidoradini; Corydoradinae; Identification key; Osteology; Taxonomy
Aspidoras Ihering, 1907
Aspidoras Ihering, 1907:30–31
(original description; type species: Aspidoras rochai Ihering, 1907,
by original designation and monotypy).
—Nijssen, Isbrücker, 1976:107‒131 (taxonomic review).
—Reis, 1998:161 (diagnosis in identification key).
—Britto, 2003:144, 146‒147 (phylogeny; diagnosis).
—Reis, 2003:291 (listed).
—Ferraris, 2007:108 (listed).
Type species. Aspidoras rochai Ihering, 1907, by original designation and monotypy.
Diagnosis. Aspidoras can be distinguished from Corydoras and Scleromystax by presenting an exclusive feature among Corydoradinae: base of pectoral-fin branched rays with small laminar expansions on its inner margin, generally more evident on first rays; laminar expansions with irregular margins, forming pointed structures, in some specimens (vs. absence). Additionally, Aspidoras can be distinguished from Corydoras and Scleromystax, with exception of Corydoras pauciradiatus, C. lacerdai and S. virgulatus, by having parieto-supraoccipital fontanel (vs. fontanel absent); from C. pauciradiatus, C. lacerdai and S. virgulatus by presenting extremely reduced to moderately developed pectoral-fin spine (vs. relatively well developed).
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| Aspidoras aldebaran, uncataloged specimen photographed alive (A), and the córrego Gordura, rio Araguaia basin, showing the typical habitat of the new species (B). Photos by Hans Evers. |
Aspidoras aldebaran, new species
Diagnosis. Aspidoras aldebaran can be distinguished from its congeners, with exception of A. belenos, A. kiriri, and A. raimundi, by having parapophysis of the complex vertebra well developed (vs. moderately developed in A. depinnai, A. lakoi, A. maculosus, A. mephisto, A. poecilus, A. psammatides, and A. velites; poorly or moderately developed in A. albater and A. fuscoguttatus; poorly developed in A. azaghal); it can be distinguished from A. belenos, A. kiriri, and A. raimundi by having inner laminar expansion of infraorbital 1 ranging from well developed to extremely well developed (vs. moderately developed). Additionally, it can be distinguished from A. albater, A. azaghal, A. gabrieli, A. lakoi, A. mephisto, A. psammatides, and A. rochai by having a narrow frontal bone, with width slightly smaller than half of entire length (vs. relatively wide, with width equal to or slightly larger than half of entire length in A. albater, A. azaghal, A. gabrieli, A. lakoi, A. mephisto, and A. rochai; extremely narrow, with width conspicuously smaller than half of entire length in A. psammatides); from A. azaghal, A. depinnai and A. kiriri by the presence of small black spots on dorsal fin (vs. absence).
Etymology. The epithet “aldebaran” refers to the red giant Aldebaran or Alpha Tauri (α Tauri), the brightest star of the Taurus constellation, deriving from the Arabic al Dabarān, which means “the follower”. The star presents a bright orange glow and it is positioned at the left eye of the mythological bull. The name alludes to the fact that A. aldebaran was firstly found among Aspidoras taurus type series (see Remarks below), being promptly recognized as a different and new species by its peculiar morphology and color pattern. A noun in apposition.
Luiz Fernando Caserta Tencatt, Marcelo R. Britto, Isaäc Jan Hendrik Isbrücker and Carla Simone Pavanelli. 2022. Taxonomy of the Armored Catfish Genus Aspidoras (Siluriformes: Callichthyidae) revisited, with the Description of A New Species. Neotrop. ichthyol. 20(03); DOI: 10.1590/1982-0224-2022-0040
