Mosquito fish is fin nipping the Guppy

[AltantaDude]

Hi,

I have one Female Guppy and added recently 8 Juvenile Mosquito fish (Gambusia affinis) into my aquarium. And recently noticed that two of the Mosquito fish are fin nipping the Guppy, especially the back fin which is in orange color. Is it common, because online when searched they said Guppies and Mosquito fish are from same family and can coexist in the same aquarium.

Thanks

 

[chromedome52]

Curious as to where you found a source that said the two species can co-exist, because I've never heard of it happening. Gambusia are quite aggressive, and seem to take particular delight in harassing Guppies.

 

[AltantaDude]

Below is one place, where they said its compatible

http://www.placermosquito.org/wp-content/uploads/2013/06/PMVCD-Mosquitofish.pdf

Edit: When searched Fishlore, couldn't find any articles about Guppy and Mosquito fishes, but now when searched just "Mosquito fish aggressive" seeing so many articles...

 

[chromedome52]

Yeah, I don't think they would notice some fin-nipping in ponds. They might notice that the guppies die out while the Gambusia thrive over the long term.

Incidentally, they still call them G. affinis. Only the native populations of Mosquitofish west of the Mississippi are this species, and most of the stocked fish come from the Eastern Mosquitofish, G. holbrooki. Formerly considered sub species, the two were separated into distinct species in 1988. The majority of Mosquitofish seen in the hobby are the latter species, as well.