i bought a black mystery snail and the lady at the store said that the black ones are a-sexual, does anyone know if this is true?

If it is truly a "mystery snail" or apple snail, no they are not asexual. The females can store sperm for a while and then produce eggs later, even if they are the only snail in the tank. Other than that, you need two to reproduce.

The "black" or "wild" version of an apple snail is just a color variation. Does your snail look like these?

If so, it is an apple snail.

Laura

yeah it looks like the black one