In-Depth Management of Egg-Laying and Eggs in Achatinidae
Managing egg-laying in giant African snails is essential. Some species lay up to 300 eggs in a single clutch, and almost as many hatchlings will emerge within a few days or weeks. Given that Achatinidae live an average of 5 years and up to 10, you will inevitably have to deal with egg management.
This is why prolific species — especially the genus Lissachatina — are not recommended for beginners, despite being relatively easy to keep.
Let’s explore the world of egg-laying and eggs in giant snails of the family Achatinidae.
EGG-LAYING IN GIANT AFRICAN SNAILS
Egg-laying in Achatinidae can occur many times a year. Some species, such as Lissachatina fulica (Férussac, 1821), lay up to 300 eggs in a single clutch, starting as early as 5 to 8 months of age [1]. All conditions in these animals are geared toward survival: frequent clutches, sometimes very large ones, a strong survival capacity through aestivation or hibernation to withstand any climate, and a wide range of possible food sources.
Egg-laying in giant snails generally takes place at night or at dusk (very rarely during the day). It is rarely possible to observe in real time, but not impossible if you pay close attention. Laying lasts several hours — between 6 and 8 hours, sometimes up to 12. If your snail is buried, it may be cooling down or in the process of laying. Do not disturb it!
Eggs are laid underground, in a corner of the terrarium or decoration, or under a food dish.
Egg-laying underground by Lissachatina fulica (Férussac, 1821)
Eggs of Giant African Snails — Achatinidae
The eggs of giant African snails range from white to bright yellow, and their size varies by species — generally small for species with large clutches, and larger for species that lay only a few dozen eggs at most.
Eggs of Archachatina marginata egregia (Dautzenberg, 1921)
The frequency of egg-laying and the number of eggs is directly linked to the snail’s calcium intake, as well as the age of sexual maturity [2]. Calcium supplementation delays the age of sexual maturity in L. flammea, promotes better longevity, but also leads to a higher number of clutches. It also improves shell strength before the first laying [3].
It is therefore necessary to provide the calcium they need for good health, while avoiding overdosing, which would have the opposite effect.
As Paracelsus said: “Everything is poison, nothing is poison — it is the dose that makes the poison.”
Infertile clutches can also occur, particularly in individuals kept alone.
Cases have been reported of individuals that lived their entire lives in complete isolation, without any contact with other snails, yet still produced offspring [4].
Egg clutches are susceptible to mould. If you notice pink spots on your eggs, there is little chance the clutch will result in a hatching.
Interior description / Coming soon
Embryo development / Coming soon
Consequences
Repeated egg-laying is a source of stress and fatigue for your snails. Snails stop feeding and draw on their own reserves to lay. This can exhaust them to the point of going into aestivation and sealing their shell with an epiphragm. This is why managing egg-laying in giant snails is essential.
Repeated clutches can lead to exhaustion and even death. It is therefore vital to provide the right food and to allow the snail to rest after laying.
These animals are programmed to survive, and laying eggs is not a sign of good husbandry conditions. Snails may choose to lay at an opportune moment, lay to ensure the survival of their species, or hold off… until it kills them.
Some species are known to lay very early — sometimes far too early. The snail may be too small to endure a clutch of such large eggs, and may die from internal injuries and/or exhaustion.
Species Requiring Close Monitoring
There are species that require absolute vigilance. Their size is often far too small relative to their sexual maturity, resulting in snails that are too small, too weak, and that die after their first clutch. These species must be kept alone until they reach a minimum size of 12 cm before any reproduction is considered. They should also be fed and have their diet boosted with pollen before being introduced to another individual.
These species are:
- Archachatina marginata grevillei
- Archachatina marginata icterica
- Archachatina papyracea
PREVENTING EGG-LAYING
Preventing egg-laying is, as we have seen, virtually impossible. It can be limited by carefully managing calcium intake which is impossible for their shell health, and by respecting the solitary nature of the species. However, there is uncertainty around the possibility of self-fertilisation, and you will inevitably have to manage a clutch at some point [4].
Monitoring and Maintaining the Terrarium to Locate Clutches
You will need to watch your snails’ behaviour very closely on a daily basis, and keep a careful eye on your terrarium — especially if it contains plants, decorations, or hides that could conceal a clutch.
Using a terrarium with transparent glass panels is also a great help. It will be essential to turn over your substrate weekly using a fork inside the terrarium.
If your snail has stayed in the same spot all day, take a look underneath it. Check whether you can spot any eggs lying around inside the terrarium. This may be due to substrate that is too compacted to dig into — in which case you will need to address this so your snail can burrow properly — or it may have been disturbed.
Sometimes, you may be able to see eggs passing through the oviduct via the pneumostome, which is a clear sign that laying is imminent.
Eggs visible through the pneumostome of an Archachatina marginata ovum (known by the nickname ‘Ovy’)
Certain species of woodlice can help aerate the substrate. You will need to find a species whose care requirements match those of your snails and that will not disturb them.
I’ve Just Found a Clutch — What Should I Do?
If you are not in a position to care for all the hatchlings (and you are not guaranteed to be able to rehome them), you will need to destroy the clutch.
Destruction is carried out in one of two ways:
- If the clutch is recent and you know it (less than 24 hours old): You can crush the eggs and dispose of them.
- If the clutch is not recent or you don’t know how old it is: Freeze the eggs for a minimum of 48 hours, then crush them before disposing of them.
As a precaution, I recommend always freezing the eggs first and making sure every single egg has been crushed.
WARNING: Releasing a species classified as an IAS (Invasive Alien Species) into the wild is punishable by law under Article L.411-5 of the French Environmental Code.
If you wish to raise the hatchlings, you will need to incubate the eggs.
INCUBATION AND HATCHING
Incubation
You can leave the eggs in the adults’ terrarium or incubate them in a separate container. This container must maintain the same humidity and temperature conditions as the adults’ setup. It is important to maintain the substrate to prevent mould. The substrate itself must be enriched.
You can also use an incubator set to the same parameters as the adult terrarium until hatching.
Exo Terra incubator with temperature and humidity control.
Hatching will occur within 8 to 21 days under appropriate temperature and humidity conditions.
My Snail Eggs Have Just Hatched — Help!
Congratulations — you now have a nest of hatchlings, known as a “clutch” or “brood,” which you will need to care for until their shells are strong enough for them to be rehomed.
Hatchlings of Lissachatina reticulata (Pfeiffer, 1845)
It is advisable to separate the young from the adults, place food and calcium nearby, and maintain the same parameters as in the adult terrarium. An appropriate substrate is essential for the wellbeing of young hatchlings: their first meal will consist of mucus and substrate, which is why a complete and nutritious substrate is so important.
You may need to try to rehome the young by looking for a sales group. Feel free to join our advice and sales Discord.
For best results:
- Wait until they reach a suitable size. When small, the shell is still very fragile. It is recommended to wait until they are at least 3 cm.
- Include a species fact sheet with your hatchlings. Inform buyers of the snails’ needs and the importance of egg management. Feel free to send them this article or include the link in your listing description.
- Arrange suitable transport (specialist carrier, hand delivery, carpooling, swap meets).
You can also choose to keep some of them to observe their development, using dedicated terrariums.
Hatchling of Lissachatina fulica (Férussac, 1821)
List of High-Output Species — Not Recommended for Beginners:
- Lissachatina fulica (Férussac, 1821)
- Lissachatina immaculata
- Lissachatina allisa (iredalei) — (does not lay eggs; ovoviviparous — gives birth to live young directly)
- Lissachatina reticulata
List of Species Recommended for Beginners:
- Archachatina purpurea
- Archachatina porphyrostoma
- Archachatina ventricosa
- Archachatina marginata ovum
- Archachatina marginata suturalis
References
[1] Bequaert J.C., 1950. Studies in the Achatininae, a group of African land snails. Bulletin of the Museum of Comparative Zoology, Harvard, 105(1):1-216.; Mead A.R., 1961. The Giant African Snail: A Problem in Economic Malacology. Chicago, USA: University of Chicago Press, 257 pp.; Raut S.K., 1991. Population dynamics of the pestiferous snail Achatina fulica (Gastropoda: Achatinidae). Malacological Review, 24(1-2):79-106.
[2] Karamoko M. et al, Effects of dietary calcium on the reproductive parameters of the snail Limicolaria flammea (Müller, 1774)
[3] Karamoko M. et al, Effects of dietary calcium on the growth parameters of the snail Limicolaria flammea (Müller, 1774), in soilless farming
[4] Meer Mohr J.C. van der, 1949. On the reproductive capacity of the African or giant snail, Achatina fulica (Fér.). Treubia, 20(1):1-10.
Photography credits:
- Aeliaflora — Underground egg-laying by Lissachatina fulica (Férussac, 1821)
- Aeliaflora — Eggs of Archachatina marginata egregia (Dautzenberg, 1921)
- V. Nobara — Eggs visible through the pneumostome of Archachatina marginata ovum (nicknamed ‘Ovy’)
- Aeliaflora — Hatchlings of Lissachatina reticulata (Pfeiffer, 1845)
- Aeliaflora — Hatchling of Lissachatina fulica (Férussac, 1821)
