Aokashi, I love this thread! Shame you forgot apple snails, though. Ah, well:
Apple snails in general:
All apple snails (genus Pomacea) have both a lung and a gill. They breath from the surface using a muscular flap that they roll into a tube called a siphon. Apple snails have distinct genders: males have the standard male "equipment", females obviously don't. Females lay eggs above the waterline in hard clumps, which can easily be removed if you don't want hundreds of tiny snail babies. Eggs hatch in 2-4 weeks, depending on the air temperature, and must be kept damp, but not wet. Adults do not eat algae unless cruelly starved, but babies and juveniles will snack on it. Algea wafers, blanched/boiled veggies, and sinking fish food provide a balanced and varied diet.
Cana complex snails: Pomacea canliculata, P. haustrum, P. maculata P. paludosa, P. insularum
These guys get BIG! There really is no getting around the 2.5 gal rule here: honestly these guys need about 5 gal each, minimum. The different species of the Cana complex look very similar, and can be nearly indistinguishable except by looking at the shape, size, and color of their eggs. These gentle giants will see your prized plants as an all you can eat salad bar, so don't put them in a tank with live plants. All members of the Cana complex are currently illegal to transport across state lines. (USA)
Pomacea diffusa (bridgesii):
Nowhere near as big as snails of the Cana complex, P. diffusa (previously P. bridgesii) grow to around the size of a golfball. These charming little snails come in many colors: gold, ivory, wild, chestnut, blue, jade, and several shades of purple. They are the most common species of apple snail seen in pet stores across the US, and most will not eat live plants, but will "prune" bits that are dead or dying. Pomacea diffusa egg clutch
How long does.it take them to get that big? I have one and Ithink he.is.so.cool!
I'm glad I have good sized aquarium!
Yay for dead algae!!! Sorry, I hate algae even more than pest snails.
Kourtney - I'm not sure how long it takes snails in the Cana complex to get full grown - I got my first two as adults. I now have around 12 babies, which are growing amazingly fast. I really depends on the temperature in their tank/enviroment and the availability of food.
I just bought two snails, I had been rolling it around and then read this and got two. I love them! They are so cute, and sneaky... Figures I'd buy sneaky snails. They wait for me to turn my back before they move, I turn around and they are quite a distance from where they were, and for the first day and a half they played dead....
I was a member of the snail avoiding brigade for a long time. Plant quarantine and dips and everything to avoid them. Then I started maintaining a little planted shrimp bowl and couldn't get control of the algae situation. Such a small system. So I went to the store and bought a little bitty gold snail to go in there. He was so little, he would surely do fine in a 1g bowl. Oops.
Now I have two of these gold apple snails (trap door kind, the ones that get golfball sized) and they've been moved to my planted forty gallon to be the heart of my clean up crew. They are always in motion, cleaning up dead plants, missed food, and even algae. They're surprisingly pretty.
They love the days when they get bits of blanched sweet potatoes (discovered this when feeding a BN pleco and found the snails on either side of the slice just going to town). I must have lucked out and gotten two males as I haven't seen any egg clutches in the many months I've had my mighty golden duo. They're about golfball sized now, but still manage to climb up my vals. Of course the vals bend when they get near the top and the snails just ride the plant down.
When shopping for apple/mystery snails, I specifically look for the trap door so I know I'm not getting anything that will reproduce on it's own or that will get massive. I don't trust the people selling the snails to have a clue that they even come in different species.
One word of warning to the betta owners: Bettas like snail antenna. They must look like little worms or something. When I first introduced my betta imbellis to my big tank, they immediately nipped those lovely antenna off of my snails. Since then, my snails have learned to duck and cover when the bettas come snooping around. I still won't put my nerites in there since they're so much smaller. I keep them in my shrimp/Endlers tank. They're much safer in there. I also don't keep a snail with my very active, hunting veiltail male. He goes through ghost shrimp like candy and I don't want to think about what he'd do to a snail. He's learned to leave the otos alone (they're faster than him), so they serve as algae control for that tank and the ghost shrimp do clean up until their luck runs out.