Ah yes, the snail grow out tank, or jar in your case. We did it for our loaches & mostly ramshorn snails but pond snails too. We thought of them as "loach candy", you may think of them as what? Assassin appetizers?
Hard to guess size, but maybe a Barterii anubias? Do you feed the jar a tiny speck of food & change some water sometimes? I don't see any filtration or even bubbles so be kinda careful. Not that both anubias & snails aren't sturdy but there can be a cumulative effects. Your water looks nice & clean... but it's hard to tell by looking...you know, test once in a while to be sure, even if it's likely fine...
Hard to guess size, but maybe a Barterii anubias? Do you feed the jar a tiny speck of food & change some water sometimes? I don't see any filtration or even bubbles so be kinda careful. Not that both anubias & snails aren't sturdy but there can be a cumulative effects. Your water looks nice & clean... but it's hard to tell by looking...you know, test once in a while to be sure, even if it's likely fine...