Phalloceros harpagos, the ellipse spot toothcarp, is a species of poeciliid fish native to Brazil.
Distribution.
"Phalloceros harpagos" is found in South America and is found in the Rio Paraná-Paraguay basin and also the coastal drainages from rio Itaboapana to the rio Araranguá.
Size.
The females of this species grow to a total length of , while males remain smaller at .
Habitat.
The fish live in tropical freshwater; and are benthopelagic. 
Etymology.
The fish is named is from Greek for hook, referring to the small and simple hook in gonopodial appendix.