After 2-4 weeks (depending on the species and the temperature, 14 days at 25°C in the case of Pomacea canaliculata) the first little snails should appear. If they don't after 3 weeks, you can try to help the young snails. It might seem rude, but it works: just break the clutch in 2 - 3 parts and those in the water. You can even wash the snail out of the clutch by moving the broken clutch parts trough the water. Note that this isn't necessairly when the moisture of the air is sufficient.
If you don't see little snails after breaking a 4 weeks old clutch, it can be that the eggs aren't fertilised or that the air moisture was too low. In the latter case the yolk is very thick or the eggs are completely dried out and filled with air. You might want to wait until the snails appear on the natural way (it can take several days before they all are hatched), but keep in mind that if the clutch isn't kept moist enough, the young snails won't be able to make their way out and subsequently die.
There are a few things to be considered to successfully breed apple snails:
- Since apple snails are gonochoristic (separated sexes), a male and a female snail are needed(obvious).
- Apple snails reproduce when the temperature rises in combination with abundance of food available.
- For those species that lay their eggs above the water, one should provide enough air space (+15cm/6 inch).
- Some species might need an aestivation period in the mud before they breed successfully (does not apply to the most common species).
It is also important to mention that female apple snails can store sperm for months, so even the eggs of a single snail can be fertile. With no male snail present, female apple snails occasionally produce infertile eggs. Obviously, these do no hatch. Last but not least: most species lay their eggs above the water and they should stay there while the eggs of aquatic layers should stay below the surface.
At the right circumstances an apple snail can produce one clutch of eggs every 4-7 days during several weeks. After this period, productivity decreases and the female snail regains strength. The species, temperature and availability of food are the main factors in the egg production