Green Swordtail

Green Swordtail (Xiphophorus hellerii)

Photo courtesy of DAR


  • Popular freshwater aquarium fish
  • Males are identified as having a large “swordtail” (USFWS, 2019)
  • Females lack a “swordtail” and only have a fan shaped tail (USFWS, 2019)
  • Red or brown mid lateral stripe (Froese, 2021)


  • Inhabits fast flowing streams and rivers around vegetation (USFWS, 2019)
  • Has been found in warm springs, ponds, and ditches (USFWS, 2019)

Impacts & Concern:

  • Largely unknown impact but has been implicated in the decline of native damselflies on Oʻahu (Nico et al., 2012)
  • Known to carry parasites that can affect native gobies (Nico et al., 2012)


  • The Green Swordtail is a popular ornamental fish and was most likely introduced through aquarium release (Nico et al., 2012)

Distribution in Hawaii (Nico et al., 2012):

  • Kauai: Present
  • Oʻahu: Present
  • Molokai: Present
  • Lanai: Not documented
  • Maui: Present
  • Big Island: Present


  • Froese, R. (2021). Xiphophorus hellerii summary page. FishBase. 
  • Nico, L., Fuller, P., & Neilson, M. (2012). Green Swordtail (Xiphophorus hellerii) – Species Profile. 
  • USFWS. (2019). Green Swordtail Ecological Risk Screening Summary. U.S. Fish and Wildlife Service.