The Panama tetra was first discovered between 1865 and 1866 during the
Thayer Expedition, when specimens were collected from the Boqueron River of Panama. These specimens were later studied by American ichthyologist
Marion Durbin Ellis, who determined that they represented a species unknown to science at the time. In 1908, she established
Hyphessobrycon as a
subgenus of
Hemigrammus and assigned this species to it, giving it the
scientific name Hyphessobrycon panamensis. However, she did not designate any of the specimens as a
holotype, so instead one of them (with the specimen number
USNM 120416) was designated as the
lectotype in 2020, while the rest became
paralectotypes. In 1917, German-American ichthyologist
Carl H. Eigenmann elevated
Hyphessobrycon to
genus level, determining that its members (including the Panama tetra) represent a separate grouping from
Hemigrammus. In 1912, American ichthyologists
Seth Eugene Meek and
Samuel Frederick Hildebrand established a new fish species which they named
Hemigrammus minutus. This was done based on analysis of specimens collected from streams in the
Panama Canal Zone, with one kept in the
Field Museum of Natural History and given the specimen number FMNH 7572, being designated as the
holotype of the species. A year later, Eigenmann determined that this species does not differ significantly from
Hyphessobrycon panamensis and should therefore be considered a
junior synonym of it. This synonymy was further confirmed in a 2020 study by additional examination of specimens that have been attributed to both names. •
Hyphessobrycon columbianus was initially believed to be a member of
Astyanax or
Moenkhausia, and later considered a variant of either
Hyphessobrycon ecuadoriensis or
Hyphessobrycon panamensis. It was first recognised as a previously unknown species and scientifically named in 2002. •
Hyphessobrycon condotensis was first named as a new species in 1913, but was declared as a junior synonym of
Hyphessobrycon panamensis in 1922. However, the former species was revalidated in 2002, and a study published in 2020 further supported its validity. •
Hyphessobrycon daguae was originally described as a subspecies of
Hyphessobrycon panamensis in 1922 under the name
H. p. daguae. It was later considered a junior synonym of either
Hyphessobrycon condotensis or
Hyphessobrycon panamensis, but a 2020 study determined that it is a valid species separate from both other species. ==References==