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| Trichomycterus vitalbrazili Vilardo, in Vilardo, Katz et Costa, 2020 |
A phylogenetic analysis using fragments of two nuclear and two mitochondrial genes strongly supported sister group relationships between a new species and Trichomycterus albinotatus, corroborated by unique colour patterns of adult specimens and juveniles, and morphology of the autopalatine bone. The new species is distinguished from its closest congener, T. albinotatus, by details of the colouration and number of branchiostegal rays. Both the new species and T. albinotatus are endemic to the Rio Paraíba do Sul basin, in the Atlantic Forest of south-eastern Brazil, but occur in distant and disjunct areas. The new species, herein described, is endemic to the upper section of the Rio Grande drainage, a right tributary of the lower Rio Paraíba do Sul, an area situated in the Órgãos Mountain Range. Trichomycterus albinotatus is endemic to an area about 200 km across, in the upper section of the Rio Preto that drains the Itatiaia Massif. However, both species are only known from localities above 1100 m asl, suggesting that they cannot survive in ecological conditions at lower altitudes. This study indicates that efforts are necessary to provide more accurate data on the species diversity and distribution of Trichomycterus in the biologically diverse and endangered Atlantic Forest of south-eastern Brazil.
Key words: Atlantic Forest, Biodiversity, Catfish, Molecular phylogeny, Neotropics, Systematics
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| Trichomycterus vitalbrazili. Brazil: Rio de Janeiro State: Nova Friburgo Municipality: Rio Paraíba do Sul basin. (a) UFRJ 12151, 88.0 mm SL (preserved holotype), left lateral view; (b) UFRJ 12151, 88.0 mm SL (live holotype), left lateral view. Caudal-fin margin of holotype is damaged, see figure 6 for correct information of caudal morphology |
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| Trichomycterus vitalbrazili. Brazil: Rio de Janeiro State: Nova Friburgo Municipality: Rio Paraíba do Sul basin. (a), UFRJ 12125, 24.1 mm SL (live juvenile paratype), left lateral view; (b) UFRJ 12125, 29.1 mm SL (live juvenile paratype), left lateral view; and (c) UFRJ 12125, 29.1 mm SL (live juvenile paratype), dorsal view. Arrow indicates the midline row with white spots, which is not visible in left lateral view of figure 3b due to the light angle. |
Trichomycterus vitalbrazili sp. nov. Vilardo,
Diagnosis: Trichomycterus vitalbrazili is
distinguished from all other congeners except T.
albinotatus by the presence of a vertical row of dark
brown to black spots on the caudal peduncle end, often
coalesced to form a precaudal bar in live and preserved
specimens (Fig. 2A–B; vs. never a similar colour
pattern); two horizontal rows of white spots on the
flank in live juveniles (Fig. 3A–C; vs. never a similar
colour pattern); and medial margin of the autopalatine
nearly straight to slightly convex (Fig. 4A; vs.
concave). Trichomycterus vitalbrazili is distinguished
from T. albinotatus (Fig. 5A–B) by possessing diffuse
irregularly shaped dark brown blotches on the flank in
adult specimens (Fig. 2A–B; vs. well-delimited dark
grey to black, sometimes coalesced in larger specimens);
fins with dark brown spots in adults specimens (Fig.
2A–B; vs. without spots); and eight branchiostegal rays
(vs. seven)
Etymology: The name vitalbrazili was given in
honour of Vital Brazil Mineiro da Campanha (1865–
1950), an important Brazilian biomedical scientist who
first discovered the polyvalent anti-ophidic serum,
successfully used to treat venomous snake bites, and
founded the Vital Brazil Institute, where the new species
was found.
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| Stream tributary to the Grande river drainage, Rio Paraiba do Sul basin, inside the advanced campus of Instituto Vital Brazil in São Lourenço road, the type locality of Trichomycterus vitalbrazili. |
Paulo J. Vilardo, Axel M. Katz and Wilson J. E. M. Costa. 2020. Relationships and Description of a New Species of Trichomycterus (Siluriformes: Trichomycteridae) from the Rio Paraíba do Sul Basin, South-eastern Brazil. Zoological Studies. 59(53). DOI: 10.6620/ZS.2020.59-53 (2020.10.13)
