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