They compete for territory, killing the other fish would just make it die, biting the fin lets it suffer
A small livebearing fish that does not eat mosquitoes. They are a pest around the world where they have been introduced because people mistakenly believed that they would control mosquitoes.
Amistad gambusia was created in 1973.
Yellowfin Gambusia was created in 1957.
Gambusia dominicensis was created in 1913.
Cuban gambusia was created in 1854.
Widemouth gambusia was created in 1975.
Pecos gambusia was created in 1853.
There is no such thing as an Australian introduced species in the Murray River. If it is Australian, it is not introduced. Species which have been introduced from overseas include various species of Carp, Brown and Rainbow trout, Redfin perch and Gambusia. The most prolific of these is the carp.
Clear Creek gambusia was created in 1957.
Big Bend gambusia was created in 1929.
Gambusia are fish from fast flowing clean streams. Air pumps on their own do very little for them. Gambusia need filters.