Specimens of Imparfinis were recently collected
in northwestern Argentina from the Bermejo River basin
(Salta and Jujuy Provinces), del Valle River (Salta
Province) and Horcones River (Santiago del Estero
Province). An integrative approach to taxonomy, combining
a detailed morphological study and molecular phylogenetic
analyses, was applied in order to determine the species
identity of these specimens. A principal components
analysis of morphological data clustered the specimens
from northwestern Argentina and from the Amazon basin,
indicating a close morphological resemblance. Also,
a molecular phylogenetic analysis showed populations
of I. guttatus from Argentina and Peru forming
a clade. According to the conducted haplotype network
analysis these populations are distinct in two mutations.
Thus, in absence of morphological or molecular data
indicating the contrary, the combined method supports
the identity of the specimens from the tributaries
of the Paraguay River in Argentina as Imparfinis
guttatus, whose type locality is in the upper
Beni River basin in Bolivia. This contribution is
also the first record for this species from Argentina.
The disjunct distribution of I. guttatus
provides new evidence reinforcing the hypothesis for
the origin of the Paraguayan ichthyofauna. We also
provide an approach to the phylogenetic relationships
of Imparfinis in Heptapteridae (Aguilera,
G. et al 2022). Aquarium Care: An
aquarium with hiding places such as bogwood, rockwork,
plants and a sand substrate. A good water flow is
recommended with good aeration and filtration. Can
be housed with small species such as tetras as their
small size does not present a hazard but may eat small
fry from other species. Diet: Small
live, frozen and flake foods.
Mamoré and Pilcomayo River basins, Bolivia
and Peru. Type locality: Popoi River,
Upper Beni [Bolivia].
Aguilera, G., Terán,
G.E., Mirande, J.M., Alonso, F., Chumacero, G.M.,
Cardoso, Y., Bogan, S. and Faustino-Fuster, D.R.
(2022), An integrative approach method reveals the
presence of a previously unreported species of Imparfinis
Eigenmann and Norris 1900 (Siluriformes: Heptapteridae)
in Argentina. J Fish Biol. Bockmann, F.A. and G.M. Guazzelli,
2003. Heptapteridae (Heptapterids). p. 406-431. In
R.E. Reis, S.O. Kullander and C.J. Ferraris, Jr. (eds.)
Checklist of the Freshwater Fishes of South and Central
America. Porto Alegre: EDIPUCRS, Brasil. Ferraris, C.J. Jr., 2007. Checklist of catfishes,
recent and fossil (Osteichthyes: Siluriformes), and
catalogue of siluriform primary types. Zootaxa 1418:1-628.
Froese, R. and D. Pauly. Editors. 2022. FishBase.
World Wide Web electronic publication. www.fishbase.org,
( 02/2022 ).