Vetrivel

The apple snail is a family of snails, while the mystery snail is a species in that family. You can call a mystery snail an apple snail, but not the other way around. More than that, although their anatomy and appearance are similar, mystery snails never grow as big as apple snails. Secondly, The mystery snail grows up to 1.5 inches in Diameter. Other apple snails, however, can grow as large as 6 inches.(In Diameter) Keep in mind that mystery snails CAN grow up to 3 inches lengthwise especially as you have measured their foot. Thirdly, Mystery snails have darker colors, such as brown, black, or blue while other apple snails have lighter shades of gold brown, pink, red or blue. Mystery snails have more slated feet. Overall, it seems to be a mystery snail.

I have seen my cherry shrimp snacking on them so i don't think they are the cause for the death of your shrimp.They are benificial to the water quality by eating debris and organic matter and work as a convenient snack for passing-by shrimp.Their population starts booming when there is an abundance of food (Likely a result of overfeeding). Having them around means you can overfeed and it won't affect the water quality.When food becomes scarce the shrimp begin hunting and feeding on them and their population goes down. I overfeed my cherry shrimp ones every 5 days.The shrimp feed on the algal bloom and the ostracoda prevent bacteria from proliferating. This maintains their population. They are laying eggs on the shrimp/snails . It does not really bother the snails and the shrimp just pick them of and eat them.