Trying to identify these fish

[Ceeeye929]

Took my son to a pond in Long Island ny and with all the recent rain many puddles had formed leaving countless life doomed .we rescued some and my son who is 4 wanted to keep some . They look like guppies except they’re smaller and colorless. Have some spotting on fins and a black dot under eyes . One looks pregnant. Any help would be appreciated because we would like to care for these fish properly

 

[Wyomingite]

They look like Gambusia affinis, the western mosquitofish. In the first half of the last century (that sounds so weird to put it that way ) they were introduced all over the country for mosquito control, because they eat mosquito larvae voraciously. I think they still are used in a few northern areas.

They ended up having a negative impact on native fish in a lot of places and have since been exterminated where they were non-native, but the are are extremely resilient and adaptable. There are still isolated population in places, even in places where they are supposed to be wiped out. They were supposedly exterminated completely in Wyoming back in the late 80's or early 90's and they aren't supposed to be able to live here long term and definitely not breed due to short summers. 10 years ago or so I found a small sheltered pond, here in Wyoming, that still has a nice little breeding population.

WYite

 

[Ceeeye929]

They look like Gambusia affinis, the western mosquitofish. In the first half of the last century (that sounds so weird to put it that way ) they were introduced all over the country for mosquito control, because they eat mosquito larvae voraciously. I think they still are used in a few northern areas.

They ended up having a negative impact on native fish in a lot of places and have since been exterminated where they were non-native, but the are are extremely resilient and adaptable. There are still isolated population in places, even in places where they are supposed to be wiped out. They were supposedly exterminated completely in Wyoming back in the late 80's or early 90's and they aren't supposed to be able to live here long term and definitely not breed due to short summers. 10 years ago or so I found a small sheltered pond, here in Wyoming, that still has a nice little breeding population.

WYite

Appreciate the info thank you