Mystery snails live about a year. The fastest growing and those that SURGE are probably females.... males do not grow as large.
This is something I put together for my facebook page RG Guppy
'I read a long time ago, they were called Mystery Snails, because sometimes they just disappear! LOL
Actually, there are 3 species that original came into the hobby about the same time, and since they were so similar the confusion was left to mystery, so it was lumped together.
The common pet in USA is the least invasive species Pomacea diffusa, formerly known as Pomacea bridgesii, which lays pinkish eggs,
- then the others lay greenish clusters (Pomacea haustrum)
- yellow/orange to bright pink clusters, Pomacea canaliculata,
- also there are others Pomacea paludosa or Florida applesnail , Pomacea maculata or the island applesnail
Pest Snails I often wonder what starts the "hate the snail" thing. They are just part of letting you know your tank is thriving, also tells us when something maybe out of balance (like over feeding.... is the worst thing happening in most early aquariums!
I have 7 or six species of snails ( say that 10 x fast) and most are considered pest snails (amber & common ramshorn, pond snail (those little black ones you speak of) 2 types trumpet snail, golden mystery (2 other colors, too) , Spixi snails . Just saw on aquabid this guy selling ramshorns (I have a ton) for 25 for 1 cup - $13 shipping! dont hate on the lowly snail! hehehe
I pull out over populations with the fork/zuc/cuc trick, when a tanks gets close to out of hand... I have dried them out and crush for feeding back to mystery snails, garden, chickens... Hey, they ate the food, so back on the wheel!