Mystery Snail or Apple Snail?

                                                                   Much confusion reigns on the Internet about which is which. This, more so in the U.S where they

                                                                                         have both varieties commercially available. Here in Australia it is quite simple, we only have the

                                                                                         true Mystery Snail available, Pomacea bridgesii  (pictured left). Brown or Tortoise shell varieties

                                                                                         are known as Pomacea diffusa, and those are still true Mystery Snails.

                                                                                         Apple Snails on the other hand are ​Pomacea canaliculata (pictured bottom right) and there are 

                                                                                         some very important differences between the two both anatomically and in behaviour.

           Pomacea bridgesii

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​Anatomically, if you look at the two pictures, you will see that the true Mystery Snail (top left) has a squared bevelled appearance where the outside of the whorl joins onto the older shell underneath. Whereas the Apple Snail (pictured bottom right) is much more rounded at this junction. This is by far the best method of identification, as colour alone proves

nothing. Behaviourally, the Apple Snail will devour live plants (a most unwanted trait for

the home aquarium) and can grow as large as a tennis ball! The Mystery Snail will only

devour plant matter that is already decaying. This is due to Mystery Snails having a softer

rasping tongue than their Apple Snail cousins and so are limited in the hardness of the

food they can ingest. Also, they only grow to around 5cm in diameter.

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Diet & General Care

A true lower food chain tank mate should be as such that they don't require more care

than the larger creatures being kept, after all, if the snails need more care than the fancy 

fish being kept (which for most owners is the point of having an aquarium) then they really                      Pomacea canaliculata  

are more trouble than they're worth.

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Not so for our friend, the humble Mystery Snail! As mentioned, they will eat fish excreta (extracting any residual nutrition remaining), decaying plant matter (which can break off and clog a filter), graze on any algae growing (they will never eliminate it but will keep it trimmed like having sheep in a paddock) and of course any left over commercial fish food being feed to your fish. They also eat rotting flesh (great if there's a dead fish in a dark corner you haven't noticed) or other dead snails. They NEVER eat any living creature, including their own young.

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Water quality isn't an issue for them, from pristine to ammonia laden (which would kill most fish), they can handle it. pH and Water Hardness is only vital to their shells. A pH of 6.0 will erode and pit their shells, so I recommend a minimum of 6.8 up to 8.5 (which is essentially marine conditions).

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​​Breeding

Breeding is another area that concerns people. Questions on the internet

range from "Will they breed in my tank and become pests?"  to "Why haven't

my snails bred yet?"  and everything inbetween.

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So let's deal with the basics. First of all, the true Mystery Snail is NOT

​hermaphroditic, both male and female are required for breeding. If you don't

see the male attached to the female via their appendage, then you haven't

got both.

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Secondly, Mystery Snails lay their eggs above water, in fact up to 6 inches

above the waterline. So if you don't have much head space in your aquarium,

they will search for a location out side the tank, where the eggs will dry out or

not hatch due to insufficient warmth. The snails themselves generally need

water temperatures of 28 degrees celsius to prime them for egg production.                                     A Close-up of a batch of eggs 

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​Even once hatched, the young are incredibly small and fragile. Prone to being sucked into a filter, starvation or just eaten by the general fish population, breeding is best left to a dedicated breeder like myself. Very few would survive so that answer's the question of breeding in numbers to become a pest!

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Survival rates increase dramatically the larger they grow. The sizes I provide are beyond the ability of most fish to regard them as food. There is one exception of course, and that is with members of the Cichlid family which can harass and persist in damaging the growing mantle edge of the shell. You have been warned!