Phalloceros buckupi, the Jacareí toothcarp, is a species of poeciliid fish native to Brazil.
Distribution.
"Phalloceros buckupi" is found in the Rio Jacareí drainage and neighbouring, which flows into the Baía de Paranaguá in Paraná, Brazil.
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 in honor of Paulo A. Buckup (b. 1959), the collector of the most specimens of this species, and for his many contributions to neotropical ichthyology.