Girardinus caudimaculatus Hensel, 1868 The dusky millions fish, speckled mosquitofish or the one-spot livebearer (Phalloceros caudimaculatus) is a species of fish native eastern and southern Brazil, northern Argentina, Uruguay and Paraguay.

[2] It has also been introduced to Australia, Malawi and New Zealand; primarily for mosquito control, but also as escapees from the aquarium trade.

[3] The dusky millions fish was introduced to a variety of ecosystems both by aquarium keepers and as mosquito pest control.

[5] It has similar features as the dusky millions fish, such as a high reproductive rate and use for mosquito control.

[5] Furthermore, this dusky millions fish has also affected the food chain, as they have become prey for native bird species.