General

What is a Giant African Land Snail?

A Giant African Land Snail is a snail that originates from Africa, of the genus Achatina, Archachatina and Metachatina. There are many different types, many of which are found in captivity. These include including Achatina fulica, Achatina achatina, Archachatina marginata, Achatina iredalei and many more.

For more information on the different species click here.

For pictures of the different species click here.

Where do they come from?

Giant African Land Snails come from Africa, but have been released by man into many different countries such as China, Hawaii, Brazil and the Pacific Islands, where they have become serious agricultural pests.

How long do they live for?

Giant African Land Snails can live for 10 years, but the average is more like 5 or 6 years.

How long do they take to become adults?

Giant African Land Snails vary in their growth rates. If kept in optimum conditions, you can expect your snails to start laying eggs between nine months and two years, depending on the species and how they are kept. Snails keep growing throughout their lifetime, but slow down on reaching maturity.

When do they stop growing?

Giant African Land Snails continue growing throughout their life, but they grow quicker when they are younger, when plenty of food and cuttlefish is available, and when it is warm enough.

Can they live outside?

In the summer they could, but they could pick up parasites from the snails that live here in the UK and die. You must never, ever release Giant African Land Snails into the wild. They would not survive our climate; they would freeze to death in the winter, they have no immunity to diseases that are carried by our native snails, and in places they would have trouble finding enough food. Basically, 'freeing' Giant African Land Snails in the UK or any country where they don't belong is extremely cruel. Owning Giant African Land Snails in some countries is illegal, let alone releasing them into the surrounding environment! If you have too many snails please contact me and I will see if I can help.

Can they bite?

Giant African Land Snails do not have teeth. Instead, they have a rough tongue called a radula, which has special ridges on it so the snails rasp their food rather than chewing or biting it. You can feel a snail rasping you. It is slightly rough, tickly sensation, not unlike the feeling of a cat licking you. It can't do you any harm. Some species (possibly Achatina iredalei) have sharper radulas than others. Snails seem to rasp most surfaces they come across. This appears to see what is edible.

Do all species lay eggs?

One species called Achatina iradelei gives birth to live young. However, in actual fact, the babies are born from eggs but these are incubated inside the snail.

Do they come in different colours?

Yes. Achatina fulicas shell range from a dark brown, through to a greeny-brown and light tan colour, and may or may not have stripes. Achatina achatina has a brown shell with tiger like stripes, Achatina iradelei have a pale yellow shell, and the body of Achatina immaculata can be a very pale grey or tan. In the separate Achatina and Archachatina species, the variations of shell and body pattern and colour vary tremendously, and sometimes only an expert can tell the different species apart.

What senses do they have?

Giant African Land Snails can sense light and dark, temperature and humidity, rough and smooth, they can taste, they can see?not sure of they can smell though in the human sense.

Do they have personalities?

I think so! Some snails are greedier and eat more, some are more laid back, some are lazy, some just rush around everywhere, and some prefer being handled to others.

How fast are they?

The average speed for a Giant African Land Snail is about 0.04 miles per hour.

What's the most common species?

The most common Giant African Land Snail you are likely to find in captivity is Achatina fulica.

What's the largest species?

The largest ever Giant African Land Snail is a species called Achatina achatina, and one individual grew to 15 inches long.

Are there any books on Giant African Land Snails?

Only one that I know of I'm afraid! It's called Your First Giant African Land Snail by Marianne Mayes or Lucy Mann, depending on which edition you've got (the book is exactly the same!) It's available from (if you are in the UK) Pets Mart (for about £1.50), and some reptile centres also stock it.

Why are they illegal to keep in the USA and other countries?

Giant African Land Snails are very, very prolific breeders. In countries where the climate is warm enough, Giant African Land Snails have escaped into the wild and bred, causing huge amounts of ecological and economical damage to the areas where they have become established (see here); they eat their way through crops meant for human consumption and cause chaos on roads. Where pesticides are used against them the carcasses of the snails rot, so that diseases spread and a foul stench encompasses the area. In the USA you can be given large fines if you are caught with a Giant African Land Snail. In the UK the climate is not warm enough for the snails to survive outside, so it is legal for us to keep them as pets.

Can they give you meningitis?

As far as I am aware, only wild caught snails that carry the disease can pass on meningitis and only if they are undercooked and then eaten. Obviously you should wash your hands after you handle any pet, and observe proper hygiene in the regular cleaning of tanks and not allowing food to rot or become moldy.

Care

How should you pick up and hold a Giant African Land Snail?

See here.

Are they easy to keep?

The easiest species to keep is Achatina fulica. They do well at room temperature, eat almost anything and grow fairly quicker. The slightly larger Archachatina marginata and Achatina achatina are more specialist species; they lay less eggs and are harder to come by.

How much do Giant African Land Snails cost to keep?

Giant African Land Snails vary in price. I've seen them in pet shops for £7 for a snail of 2 inches! The most expensive thing about snails keeping is probably their enclosure. You can go out and buy an aquarium to keep them in; I go for the cheaper option of using clear plastic storage boxes, that cost from £1.99 for a small one for babies, to over £10.00 for a big one for the adults. Giant African Land Snails need cuttlefish for their shells, peat for the substrate and obviously food.

What do Giant African Land Snails eat?

Giant African Land Snails can eat a wide variety of foods, from fruit and vegetables, to rotting meat and even cardboard! Click here for more details.

Breeding

How many eggs does a Giant African Land Snail lay?

The species Achatina fulica can lay over 300 eggs in one go, but species such as Archachatina marginata lay much fewer, from one to twenty eggs at a time.

How can I get rid of unwanted eggs?

Freeze them for a couple of days, crush them or burn them. See breeding for more information.

How can you tell if a snail is sexually mature?

The snails which develop aperture teeth and/or reflected lip are sexually mature when these features are developed. For those without these physical features only size can be used. When the shell is almost full size, it is sexually mature. [1]

What and where are the snail's sex organs?

The reproductive opening is located in the head! The reproductive organs themselves are in the visceral hump. [1]

How do snails find a mate? Is it at a snail's pace?

The method used is slime trail following. The same method as prey detection. [1]

Do snails have courtship?

You bet! Reproduction in some hermaphroditic snails begins by engaging in a preliminary love-play. A pair of snails raise the creeping sole of their feet off the ground and bring them together. At the same time they rock their bodies to and fro and actively caress one another with their greatly extended tentacles. After a short time the love-play passes into a love-duel; each snail projects its calcareous love-dart into the sole of its partner's foot (only if the snail has a dark sack). Thereupon the two animals become interlocked, often for a long time, until they once more raise themselves and the actual mating occurs. During mating each everts its penis and ejects the fertilizing sperm into the vagina of the partner. The two snails then separate, and each stores the sperm of the other until its own eggs have ripened. [1]

Does self-fertilization occur?

Cross-fertilization is the rule but self-fertilization does occur. [1]

Does self fertilization have genetic problems?

Most freshwater snails can self-fertilize for two or three generations without difficulty in genetic factors. Pulmonate snails will use cross-fertilized sperm in reproduction in preference to sperm from the same individual. This ability of self-fertilization is a very significant feature, because it enables the snail to establish a new colony by means of a single individual. This is only possible if the individual can hold out for a fairly long time at its new location. In every possible situation it will use cross-fertilization to maintain genetic diversity. [1]

How do eggs develop?

When the young are hatched, they are miniature adults. There is no metamorphosis or molting. Young snails grow by the mantle adding material to the leading edge of the shell which in turn adds morewhorls. The Achatina fulica snails in a clutch emerge to the surface en masse, usually within a few hours. In some cases, one or two individuals force a path through the sand to the surface and the others following the same route. After hatching, they eat their shells, and sometimes the shell of unhatched siblings. Much of the growth is in the first month with a little less in the next two months. [1]

How many offspring can a snail have during its lifetime?

We have some information about the egg laying capacity of Achatina fulica.

ASSUME: Achatina fulica has a life span of about 6 years. Reproduction starts at end of year 1 and continues for 5 years followed by death. Yearly eggs per reproductive year per individual 100, 300, 400, 200, 100. Since Achatina are hermaphroditic, both parents can produce off springs!

Parents End Generation Year 1 2 3 4 5 0 0 1 200 0 2 600 40,000 3 800 360,000 1.6 x 109 4 400 640,000 129.6 x 109 2.6 x 1018 5 200 160,000 409.6 x 109 16,800 x 1018 6.8 x 1036

Parents 2,000 2nd gen 1,200,000 3rd gen 540,800,000,000 4th gen 16,800,000,000,000,000,000,000 5th gen 6,800,000,000,000,000,000,000,000,000,000,000,000

Only two surviving offspring are required during the parent's lifetime to insure a no growth or stable population. The remainder die from parasites, predators, desiccation, and old age. Let's try to visualize the magnitude of these numbers. If we further assume that a shell is one square inch in cross-section and all the shells are standing vertically, they would cover the entire surface area of 7,700,000,000,000,000,000 worlds or if the shell is 6" tall, cover one world to a depth of 720,000,000,000,000 miles. [1]

Problems

Why does my snail eat it's own shell?

Ingestion of the shell is odd but may signify a lack in calcium thus the snail is satisfing it's needs by absorbing it's own reserve.

...and I always wondered if another reason they do it may be to smooth rough edges on the shell that are irritating them, but that's just a theory :) Whatever the reason, unless it's very excessive, they never seem to do much damage.

My snail seems to have stopped eating and isn't coming out of it's shell much either - what can I do?

Have you got a heat mat for your snail? Sounds like it could have gone into hibernation. You need to either use a heat mat, or keep it in a warm place (and spray it with warm water). If you can get a mat it's best - they're about £11 for a small one, you don't need one that covers the whole tank. Too much or too little moisture can also cause hibernation.

Leave the mat on all the time, and leave the tank on it - they take a week to start to get back to normal - takes this time for them to decide that the heat will be constant, and won't disappear suddenly. Don't do what I did one year - keep moving the tank on and off the heat source - they get confused and it takes even longer to get them out! :) You could also try holding the snail under warm running water, or popping him in a saucer, but make sure it's not too hot or deep!

Another thing I found with mine - if they are out but not eating, try putting them in the middle of the tank, or away from wherever they like to hide, in the case of mine it's their tunnel, and then ring them with food, so that to get back to their hiding place they need to cross it - they tend to take a nibble on the way! I'm still doing this every night with my biggies, and it seems to have worked so far.

Can they rebuild their shells if they are damaged?

Sometimes Giant African Land Snails' shell will break off at the mouth of the shell, where the snail's body emerges. This will re-grow quickly; just make sure the snail has plenty of cuttlefish and a good supply of food. If a snail falls from the top of its tank and makes a hole in the shell, you may need to repair the shell yourself or the snail may die. See the page on Shell Damage.

Misc

What makes a snail a snail?

In its simplest form a snail can be thought of as consisting of a body mass (visceral hump) covered with protective armor (shell) from which extend sensory-feeding and locomotive areas (head and foot). [1]

What is the life-cycle of a snail?

The driving force in the life-cycle (youth, adult, old age) of a snail is reproduction. The stages are determined by their reproductive potential. Youth has no reproductive capacity, adult has the maximum capacity, and old age has a low capacity. In old age when the capacity declines the individual is not reproductively useful and dies. [1]

Are snails successful animals?

If success is measured by how long you've survived, snails are very successful. They've been around 500 million years. If successful is how well you've adopted to the environment, snails have adapted to all climates and altitudes. It has emerged from the water and now lives a diversified life in a new environment and is found from the tropics to the tundra and from sea level to mountain heights. [1]

How strong are snails?

The muscular strength of snails is surprisingly great. An experiment on a Helix aspersa weighing 1/4 oz showed it could drag vertically a weight of 2 1/2 oz., or ten time its own weight. Another snail weighing 1/3 oz. was able to drag in a horizontal direction along a smooth table twelve reels of cotton, a pair of scissors, a screwdriver, a key, and a knife, weighing in all no less than 17 oz. or more than fifty times its own weight. This was much the same as asking a man of 168 pounds to pull a load of over 4 1/4 tons. [1]

How fast are snails?

There is the "snail's pace". A movement of a few inches per minute is common for large snails or slugs. Small relatives of the operculate genus Colobostylus can move 7 times their shell length each minute. A few larger land snails "lope" or "gallop" by creating extraordinarily large locomotor waves in the foot. The speed of the European garden snail, Helix aspersa, is dependent on the surface on which it moves. The average speeds for movement on a paper towel is 6 1/3 cm/min, on a glass plate 8 1/3 cm/min, and on a formica surface 17 1/3 cm/min. [1]

Misc

Is it true that snails can be both boys and girls at the same time?

Giant African Land Snails are hermaphrodites, meaning that a Giant African Land Snail carries both male and female sexual organs. (Here for more information) They do need another snail to mate with before they can produce fertile eggs, but can store sperm for a long time, so that they can wait until the conditions are perfect for laying their eggs.

What is the radula?

The other uniquely snail organ is the radula. This is essentially a 'toothed tongue.' There are from a few to a quarter of a million teeth mounted on this flexible membrane. This structure is partly extruded from the mouth and licked or scraped across the surface on which the snail is feeding. Worn or dull teeth are discarded at the anterior end of the radula. New replacement teeth are formed at the posterior end. The tooth bearing membrane gradually grows forward, moving new teeth into the feeding position and worn teeth to the area where the membrane can be reabsorbed by the animal. The teeth fall off and may be swallowed with the mollusk's food. Naturally surrounding and operating the radula are a complex mass of muscles. [1]

What is the foot and what does it do?

The snail foot is used for locomotion and is essentially a broad, flat organ which uses ciliary waves and/or muscular contractions for clinging or gliding. [1]

Why are some shells of the same species thick and some thin?

The availability of calcium in their diet determines if the shell is thick or thin. Many years ago in the 1930s juvenile shells of Arianta arbustorum, a common European land snail were raised under two diet conditions - calcium rich and calcium deficient. It was observed that both lots grew to the same size but those grown on the calcium rich diet had shells almost four times heavier than those grown on a calcium deficient diet. I have observed this diet restriction in Achatina fulica living on volcanic (calcium deficient) and coral (calcium rich) islands of the Pacific. [1]

Why are there so many shell shapes?

A 1980 study showed that high-spired shells with multiple whorls prefer to crawl on vertical surfaces. Those with depressed shells and usually with fewer whorls generally prefer horizontal surfaces. Why are the ground burrowers usually high spired? Maybe because it is easier to burrow if you are pointed. This is an observation and does not explain why. [1]

How can you determine if the shell is an adult?

The teeth and reflecting of the lip usually occur when the animal is sexually mature or full grown. This assumes that the adult species has teeth and/or a reflected lip. [1]

Where does the beautiful color come from?

The shells are not, as is often thought, painted or dyed. The colors are sometimes determined by heredity but in some species can also be influenced by the diet of the animal. Color in mollusks often serves as camouflage, but some pigments are primarily structural in function, serving to strengthen the shell. The yellows and reds of beta carotene are an example. Other colors, usually iridescent "mother-of-pearl" hues, are due to light refraction in combination with the actual structure of a translucent shell material. [2]

How are shell color patterns formed?

The shell itself is being continuously deposited throughout its life. The deposition of pigment which produces its color pattern is therefore a biochemical record of the individual snail from cradle to grave. The shell pattern is a graphic record of the secretion activity along a line of cells on the mantle edge. The ground-color is produced by the whole cell line and banding by special groups of cells. Where the activity of these groups of cells is cyclical, blotching results. Where the activity focus moves up and down along the mantle edge, or where activity spreads from a focus, zigzag or hollow V-shaped patterns result. [1]

How do they make all those beautiful patterns?

The patterns and designs on shells are produced naturally by the animal that makes the shell, and the pattern is actually part of the shell, not a surface ornamentation. Each species has some patterns that are common to its members. [2]

Is there a correlation between color and habitat?

In general, tree dwelling snails are bright colored and tend to become elevated or conical, while ground snails are duller or brown, and usually depressed. [1]

Why does the same species have variations in the color pattern?

Birds are a principle predator of land snails. They use "pattern recognition" to identify prey species. If 70% of the snail shells have three spiral bands and the remainder have two or four, the birds will prey on the 70% and the remaining 30% will be safe. Variation in the shell pattern is an effective means to insure species survival from a "pattern recognition" prey. [1]

Do snails repair damage to their shells?

Snails do actually restore broken parts and heal over breaks in their shells. [1]

How is the repair made?

These two grades of restoration correspond to the two diverse shell making regions of the mantle. The young marginal part of the mantle is able to make all the outer layers with its colors and architecture. The older parts of the mantle far from the mantle margin can only add innermost layers to the shell or function after breaks to supply a sort of cement to mend the break but not to actually restore it to look like new. [1]

How do land mollusks breathe?

In the air-breathing pulmonates the interior of the mantle cavity is converted into a lung and a pumping mechanism for renewal of air is established. The restriction of the respiratory aperture is necessary. The mantle forms the roof of the cavity and is covered with ridges in which pulmonary veins converging towards the auricle. The floor of the cavity is arched and has a layer of muscles, which contract rhythmically. When the muscles contract, the arch flattens and air is drawn in and at the limit of contraction a valve slides across the pneumostome. When the muscles relax, the cavity decreases in size and exchange of gases with the blood in the roof vessels is facilitated by the increase of pressure of the contained air. Then the pneumostome opens and air is expelled; the subsequent contraction of the floor muscles brings in a fresh supply. This 'breathing' is not so regular or so frequent as in a vertebrate; moreover, it may cease altogether in the winter when the snail hibernates. [1]

What is the air consumption of snails?

Some snails kept in containers three times their volume were alive after several days. [1]

How do snails which live in cold regions avoid freezing?

They build up an antifreeze in their blood. [1]

How do snails handle their need for water?

Most snails are probably more water sensitive than is usually believed. The humidity of the air affects the surface of their skin to a considerable extent. Every one has noticed how the snails 'come out' on a damp evening, especially after rain. The mucus of slugs and snails besides its use in facilitating locomotion, is a contrivance for checking evaporation by surrounding the exposed parts of the bodies with a viscid medium. The mucus has an affinity for water. Consequently when you try to rid your fingers of mucus do not get them wet. This will only make the mucus more fluid and sticky. To remove the mucus rub your hands together and the mucus will dry and peel off like glue. The pulmonate snail can carry an extra supply of water in the pallial cavity. This extra water supply permits them to be more active than operculates. Since the pulmonate can be active at lower humidity because of its extra water supply, they will return to activity before the operculates. [1]

What is the difference between hibernation and aestivation?

Hibernatation is to spend the winter in a dormant state and estivation is to pass the summer in a dormant state. [1]

How do snails hibernate or estivate?

In hibernation or aestivation operculate and pulmonate snails react similarly. The heart of the pulmonate may slow down from 36 beats per minute to only three or four. In the operculates it may drop from 53 to only two to three times per minute. As an indication of how much body processes are slowed down, a hibernating pulmonate at 30°F will use as little as 1/50th the amount of oxygen used by an active snail at 59°F. [1]

Is estivation only done to combat weather?

There is direct correlation between estivation and reduced moisture in the environment. There is a tendency in an individual for phases of estivation to alternate with phases of activity. Even under approximately constant external conditions some of the animals would be in either phase. The reason for estivation is a low water content, and that the latter may be brought about either by dryness of the environment or else by the natural hydration cycle of the animals. [1]

Is preparation needed for cold or estivation?

Snails will adjust to remarkably low temperatures if they are arrived at slowly enough. Snails put suddenly in a cold chamber will die in a short time. Yet if several days are taken to gradually reach the temperature in the cold chamber, these snails will undergo physiological changes, including the alteration of the water content of the cells, and withstand successfully the lower temperatures for prolonged periods of time. [1]

Sources