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From
its original home in East Africa, this popular and easily kept pet,
has been spread sometimes accidentally, sometimes deliberately,
to many areas of the tropics and sub-tropical, sometimes developing
into a considerable pest. In East Africa, giant snails of a number
of species are eaten, and in East Africa they are fed to domestic
animals, particularly ducks.
The
average adult specimen of this species has a shell length of about
10 cms, streaked and mottled with purple, white and fawn. The largest
known specimen was 30 cms long when fully extended and had a shell
20 cms in length. The species continues to grow and enlarge its
shell even after reaching sexual maturity.
These
snails east most tropical plants and fruits. If offered cabbage,
they prefer the darker outer leaves. They don't seem to like grass
very much, if at all.
As
well as plenty of food, calcium must be provided. Either by adding
clear, crushed eggshells, chalk, or chunks of cuttlefish to the
compost. Snails deficient in calcium develop a crumbly, rough shell
and will probably not breed.
A
suitable container is any sort of glass or plastic container, such
as a plant propagator, with a securely fitting lid. It doesn't have
to be particularly large as two snails in a container 20 x 13 x
16 cms in height, seem quite happy and breed readily. Ventilation
can be provided by two small holes approximately 6 mms in diameter.
The
substrate should be some form of moistened potting compost. If you
introduce a few earthworms when you are setting up, they will keep
the compost fresh longer. A few woodlice will clean the surface
of scraps and seem to become self-perpetuating easily, without becoming
over-crowded.
If
you are interested in British snails, there are several common species.
The brightly and individually coloured Banded snail Ceprea nemoralis
is perhaps the most attractive. The common brown garden snail, and
the closely related Roman snail are also interesting in that they
are extremely long-lived - up to 16 years being not exceptional.
If they are proving to be a pest in the garden, don't kill them!
Just lay out lettuce leaves in the late afternoon and collect the
snails, then remove them far away (not just over the fence into
a neighbour's garden!) If you want some additional interest,
you could try a blob of nail laquer or Tippex on the shell so you
can identify the snail. If you put them 50 or 100 metres away, they
will be back within two days!
All
snails are hermaphrodites. In captivity, watching for signs of mating,
as the specially created calcium love-dart, or penis has been seen
by few people. The actual act reminds one of a couple of Galleons
pulling up alongside each other, and stretching out a grappling
hook!.
After
mating, between 30 and 150 eggs will be laid and loosely covered
with compost or hidden under a piece of bark. For Giant snails,
they are about 5 mm long and hatch after 10 days if incubated at
25 degrees celcius. After eating their own shell, the baby snails
move straight onto adult food, maturing in six to nine months, depending
on temperature and food.
The
zoopark has maintained Giant African Land Snails for many
years, keeping then at the moment in the Education Department
where they are used for close contact "meet the animal" encounters.
They bred on numerous occasions, and especially at the 1988 Glasgow
Garden Festival, when their pearl-like eggs were much admired
by some of the 800,000 visitors to the Hugh Fraser Tropicarium
- an enormous Orchid and Butterfly House.
The
Zoopark also maintains an Urban
Wildlife Garden which as any undergrowth or weeding material
recycled, through its own compost heaps within the Garden is full
of general species of snails and slugs, all of which can be observed
without difficulty feeding, either by searching the dry-stone walls,
or under the logs, or on the natural food plants.
The
common pond snail (Limnaea stagnalis)
How
long does it take for pond snail eggs to hatch?
'The
eggs are laid at intervals during the summer; they are deposited
about thirty at a time, embedded in a curved mass of jelly, which
is nearly an inch long; this is usually deposited on some water-weed
to which it adheres. The young snails hatch in about a month. They
do not at once need to rise to the surface for a supply of air,
for they are hatched with a lung-cavity full of water and probably
they are capable of respiration through the skin, using the air
dissolved in the water.
The
growth of the young snail is fairly rapid at first; in three months
the shell may be nearly an inch long,but the full size is not attained
for two years.'
Indonesian
Snails are also on view to visitors at the Zoopark.
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