Hollandichthys is a genus of characin, or tetra, endemic to the coastal Atlantic Forest drainages of southern and southeastern Brazil. Hollandichthys multifasciatus, the banded tetra, has long been recognized in the ichthyological literature, while Hollandichthys taramandahy was described more recently, a reminder that even long-known river systems close to Brazil's population centers keep yielding new species from their fragmented, shaded forest streams. At 3.5–4 in, both species run larger than many popular aquarium tetras.
Field studies on Atlantic Forest stream fish have documented Hollandichthys taking fallen fruit and seeds from overhanging vegetation, an unusual foraging habit for a tetra that ties the genus into the seed-dispersal networks of its forest habitat rather than the more typical insect- and algae-based tetra diet. In the hobby, the banded tetra has occasionally been kept by tetra specialists for its striped pattern, while Hollandichthys taramandahy remains essentially unknown in the trade. The split IUCN picture - Least Concern for one species, Vulnerable for the other - reflects the heavily fragmented, deforested state of much of Brazil's Atlantic Forest lowlands.