What Is This A Wild Guppy,molly Or Mosquitofish

[misterpro]

Yup, livebearers can drop several batches of fry without the need of a new "visit" from a male.  They can give birth for months after being separated.

 

[Ruskull]

Yup, the above poster is 100% correct.  You can have several batches of fry without further interaction with a male.

 

[helterskelter]

Yes in a Gambusia and most likely affinis affinis 
Saving fry from these means your doing a good job, these are very nasty fish and as you found out will kill fish of a similar size!
Fry though are almost impossible to catch, unless you glue their mouth shut!