new synonymy:
Hyphessobrycon meridionalis Ringuelet, Miquelarena & Menni, 1978
is a senior synonym of
Hyphessobrycon nicolasi Miquelarena & López, 2010
published in:
Terán, G.E., S. Bogan, M.S. Vargas, F. Alonso & M.M. Montes (2025):
Parasitology aiding fish taxonomy: Hyphessobrycon nicolasi as a jr. synonym of H. meridionalis (Characiformes: Acestrorhamphidae).
Revista del Museo Argentino de Ciencias Naturales 27 (2): 305-313
abstract (from publication):
This study provides strong evidence in favor of considering Hyphessobrycon nicolasi as a junior synonym of Hyphessobrycon meridionalis. The analysis of the type material of H. nicolasi shows that the main diagnostic character between those species, which was based on supposed differences in coloration patterns due to the presence of an oblique black stripe along the margin of the caudal fin lobes in H. nicolasi, was in fact caused by metacercarial infection in the type specimens of H. nicolasi. Additionally, further examination of the types and other comparative materials did not reveal any other consistent phenotypic differentiation between these two taxa. Therefore, we consider Hyphessobrycon nicolasi as a junior synonym of Hyphessobrycon meridionalis. This finding highlights the importance of carefully considering the presence of parasites while describing new species of fishes as they can cause color changes or morphological alterations in their hosts.