That's a baby assassin snail Congratulations! It' will not reproduce unless you have a male/female together. I have (4) of them and they love my MTS snails and ramshorn snails as a meal. They love bloodworms if you do not have snails for them to feed on.
I just got one from a dealer at this years Aquafest. If I had the money and hadn't left my brain at home I would of at least gotten two. What a neat creature. I hope my angelfish will leave it alone when it sticks it's neck out.
It's the best way of getting rid of snails, they ate of all them in my 180L tank, in a matter of weeks (I have 3 of them).
I am not sure what they're eating now, they're hiding most of the time.
I hope they're still alive :icon_conf