Tuesday 18 May 2004
In the first of our occasional series of stories about the inhabitants of London Zoo, we focus on water-loving Florida apple snails
London Zoo's biodiversity centre, B.U.G.S! is home to a fascinating invertebrate called a Florida apple snail (Pomacea paludosa). These snails are mostly aquatic, preferring to spend the majority of their day under the water, leaving only occasionally to lay their bright pink eggs.
As you will see from the picture, the apple snail's shell is a green-yellow colour with reddish streaks and dark bands, the body of the snail is pale grey with dark pigments on the upper side. These beautiful snails grow to about 55mm wide and 65mm high.
The young of this species hatch from bright pink eggs that are laid above the water level. The adults lay clusters of between 10 and 80 eggs surrounded in a jelly-like substance to protect them drying out and from predators. The eggs begin to hatch just two weeks after they are laid and as the young emerge they drop into the water.
Bright pink apple snail eggs
Despite being mainly aquatic, Florida apple snails are well equipped to survive periods of drought. They can seal the entrance to their shell, using their 'operculum,' or shell door, when they are inside to maintain a suitable moisture level within and to also protect them from predators.
Interestingly, unlike most other snails, apple snails are not hermaphrodites, this means that they have distinctive male and female sex organs and that a snail of each sex is needed to reproduce.
As their name suggests, Florida apple snails are native to the Florida Everglades and are the staple food stuff of the endangered Florida kite (Rostrhamus sociabilis plumbeus). Man's draining and development of the Everglades affects the habitat of the apple snails and therefore decreases the abundance of food stuff for the kite. The kite was classified as endangered in 1967 but the population has increased slightly since this time due to conservation measures and improved management of the water ways, which has in turn increased the apple snail population.
Two apple snails side by side
Apple snails are popular aquarium pets but, as with any aquarium animals, it is important to ensure that stock comes from a responsibly managed source.
Come to London Zoo to see the apple snails in action and help us to protect endangered species throughout the world.