 The lemon tetra is an Amazon River fish species, first collected from the basin of the Rio Tapajos, near to Santarém, Brazil.The fish can be found in both the Rio Tapajos and stretches of the Amazon proper in this region (the Rio Tapajos joins the Amazon at Santarém).The lemon tetra inhabits clear waters with a modest to moderate current flow, remaining in shallower waters in close proximity to stands of aquatic plants.