Abstract
Leporinus bleheri was described for the Guaporé-Iténez basin, in the border between Bolivia and Brazil. More recently, specimens of a similar-looking banded Leporinus were sampled in distinct rivers in the Madeira basin. Herein, we use an integrative approach combining molecular and morphological data to investigate the taxonomic status of the new samples. Morphometric data were used to perform a Principal Components Analysis (PCA). Both species specimens were cleared and double-stained for osteological description. DNA barcodes were used to investigate the genetic distance between samples and for species delimitation analyses. Molecular markers COI, CytB, 16S, Myh6, RAG1, and RAG2 were applied to estimate the phylogenetic relationships of the two species. Our results show morphological and genetic differences between samples of L. bleheri and the new species. Both species are herein (re)described and illustrated. The new species is distinguished from L. bleheri by having 12 scale rows around the caudal peduncle (vs. 16). The genetic distance between the new species and L. bleheri was of 3.93%, and species delimitation analysis recovered the samples as separated molecular units. The multi-loci analysis corroborated the sister-group relationships between both species, including them within the Leporinus fasciatus group, which was recovered as non monophyletic.
Keywords: Anostomoidea; Amazon; Ostariophysi; Species delimitation analysis; Taxonomy
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| Leporinus lignator, MZUEL 21727, holotype, 152.96 mm SL (A), MZUEL 21726, paratype, 117.01 mm SL (B), and holotype in life (C), type-locality (D), Machado River, Madeira River basin, Brazil. |
Leporinus lignator, new species
Diagnosis. Leporinus lignatoris distinguished from all other anostomids except L. affinis, L. altipinnis, L. bleheri, L. desmotes, L. enyae, L. fasciatus, L. jatuncochi, L. pearsoni, L. tigrinus, L. villasboasorum, and L. y-ophorus, by having dark vertical bars encircling the body in adults and nine branched pelvic-fin rays (vs. horizontal bars, dark blotches or dark transversal bars not encircling the body, and eight branched pelvic-fin rays). Leporinus lignator is distinguished from the formers except for L. bleheri and L. tigrinus by having three unicuspid teeth on the premaxillary and four on the dentary (vs. 3/3 or 4/4). Leporinus lignator is distinguished from L. bleheri and L. tigrinus by having 12 scales around the caudal peduncle (vs. 16).
Etymology. The specific epithet, lignator, is allusive to its type-locality, the Machado River, part of the Madeira River basin. In Portuguese, Machado means axe, and Madeira means wood. Lignator is Latin (m.) for a lumberjack who cuts trees into logs, often using axes. A noun in apposition.
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