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Start your own Snail Farm
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SPECIAL REFERENCE BRIEFS
RAISING SNAILS
--------------
NAL SRB 88-04
MARCH 1988
Prepared by:
Sheldon Cheney
Reference Branch
United States Department of Agriculture
The National Agricultural Library
Beltsville, Maryland 20705
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Since information on raising edible snails is not readily
available in English, the information in this publication has been
compiled from numerous sources which are believed to be reliable. The
information applies to several different species of snails, and not
all of it necessarily applies to a specific species.
Introduction
Snails have been eaten since prehistoric times. Roasted snail
shells have been found in archaeological excavations. In ancient Rome,
there were "cochlearia," gardens where snails were fattened up before
being eaten. Pliny described the snail garden of Fulvius Hirpinus 2000
years ago as having separate sections for different species of snails.
Hirpinus allegedly fed his snails on meal and wine. (But note, beer in
a shallow dish is a way of killing snails and slugs.) The Romans
selected the best snails for breeding. "Wall fish" were often eaten in
Britain, but were never as popular as on the continent. Snails were
often eaten during lent on the continent. In a few places, large
quantities of snails were consumed at Mardi Gras or Carnival, as a
foretaste of lent.
Edible snails also played a role in folk medicine, and recent
study has shown that glandular substances from the edible snails cause
agglutination of certain bacteria, and therefore could be of value
against whooping cough and some other diseases. Snails also host
parasites and disease organisms, however.
The United States imports $200 million worth of snails annually,
primarily from Taiwan and France. Many of the canned snails shipped
from France are snails that were imported to France from Turkey and
Eastern Europe and packed or relabeled. France presently imports a
major portion of the snails the French consume, since snails of edible
size are scarce in France due to overharvesting and due to the
increasing use of agricultural chemicals.
Edible Species
There are thousands of varieties of land snails, ranging in size
from very tiny ones about one millimeter long to the Giant African
snail which occasionally grows up to a foot long. "Escargot" most
commonly refers to either Helix aspersa or to Helix pomatia, although
some other varieties of snails are eaten, and the Giant African snail,
Achatina fulica, is sliced and canned and passed off on some consumers
as escargot.
Helix aspersa, the French "petit gris," or "small grey snail,"
the "escargot chagrine," "La Zigrinata," measures 30 to 35 mm across
the shell when mature. The shell of a mature adult has 4 or 5 whorls.
It is native to the shores of the Mediterranean and up the coast of
Spain and France. It is found on most of the British Isles, where it
was introduced in the first century A.D. by the Romans. (Some say it
page 1goes back to the Early Bronze Age.) This variety was introduced
into California by French immigrants and has become a serious pest. It
was introduced into a number of Eastern and Gulf states even before
1850. It has also been introduced into other countries such as South
Africa, New Zealand, Mexico, and Argentina. Helix aspersa has a life
span of 2 - 5 years. Helix aspersa is more adaptable to different
climates and conditions than many snails, and is found in woods,
fields, sand dunes, and gardens. This adaptability not only increases
aspersa's range, it makes farming aspersa easier and less risky.
Helix pomatia, the "Roman snail," "apple snail," "luna," "La
Vignaiola," the German "Weinbergschnecke," the French "escargot de
Bourgogne" or "Burgundy snail," or "gros blanc," measures about 45 mm
across the shell. It is native over a large part of Europe and lives
in wooded mountains and valleys up to about 6,000 feet (2,000m)
altitude as well as in vineyards and gardens. It may have been
introduced into Britain by the Romans. It has been introduced into the
U.S. in Michigan and Wisconsin by immigrants. Helix pomatia is
preferred by many over Helix aspersa for its flavor and its larger
size, as the "escargot par excellence."
Otala lactea or Helix lactea is popular with Italians, and is
sometimes called the "vineyard snail," "milk snail," and "Spanish
snail". It has a white shell with reddish brown spiral bands. The
shell is about an inch to 35mm in diameter. Considered better tasting
than aspersa by many. This snail has become established in California,
Texas, Georgia, and a few other states.
Iberus alonensis, the Spanish "cabretes" or "xona fina," measures
about 30mm across the shell.
Cepaea nemoralis, or Helix nemoralis, the "wood snail," the
Spanish "vaqueta," measures about 25mm across the shell. It inhabits
central Europe and has been introduced and established in a number of
states, ranging from Massachusetts to California, from Tennessee to
Canada. Its habitat ranges widely from woods to dunes. It mainly eats
dead plant material, but it likes nettles and buttercups and it also
eats dead worms and dead snails.
Cepaea hortensis, or Helix hortensis, the "garden snail,"
measures about 20mm across the shell and has distinct dark stripes. It
is native to central and northern Europe. It was introduced into
Maine, Massachusetts, and New Hampshire in colonial times but never
became established. Its habitat varies like C. nemoralis, but C.
hortensis is found in colder and wetter places than nemoralis. Some
say that snails with striped shells are not very good. This plus their
smaller size make hortensis and nemoralis less popular.
Otala punctata or Archelix punctata, called "vaqueta" in some
parts of Spain, measures about 35mm across the shell.
Otala vermiculata, or Eobania v. or Helix v., the "vinyala,"
"mongeta," or "xona," measures about 25mm. It is found in
Mediterranean countries and was introduced into Louisiana and Texas.
Helix lucorum measures about 45mm across the shell. It is found
in central Italy and from Yugoslavia through the Crimea to Turkey and
around the Black Sea. It is sometimes known as "escargo turc."
Helix adanensis comes from around Turkey.
Helix aperta measures about 25mm. Its meat is highly prized. It
is native to France, Italy, and Mediterranean countries and has become
established in California and Louisiana. Sometimes known as the
"burrowing snail," it is found above ground only during rainy
page 2weather. In dry weather, it burrows 3 to 6 inches into the
ground and estivates until rain softens the soil.
Theba pisana, the "banded snail," the "cargol avellanenc,"
measures about 20mm, and lives on dry, exposed sites, usually near the
sea. Native to Sicily, it has been spread to several European
countries, including England. This snail is a serious garden pest and
is the "white snail" that California once eradicated by using
flamethrowers to burn off whole areas. In large numbers, up to 3,000
snails per tree, it can ravage a garden in 24 hours and a citrus or
other crop in a couple of nights.
Sphincterochila candidisima or Leucochroa candidisima, the
"cargol mongeta," or "cargol jueu," measures about 20mm.
Achatina fulica, the Giant African snail, grows up to 1 foot
long, overall body length. This snail was purposely introduced into
India in 1847. An unsuccessful attempt was made to establish it in
Japan in 1925. It has been transported to other Pacific locations both
on purpose and accidentally and is now a serious pest in many places.
It has been introduced into the U.S. around Miami and Hollywood and in
Hawaii, where it not only causes crop damage, but, due to their large
size, it is a nuisance due to the slime and fecal material and the
smell when something like bait causes large numbers to die.
Considerable effort has been made to eradicate Achatina.
Terms such as "garden snail" or "common brown garden snail" are
rather meaningless since they are applied to so many types of snails,
but they sometimes mean Helix aspersa.
Restrictions
The same snails that some persons raise or gather as food are
seen as a major pest by others. Introduced slug and snail varieties
tend to be worse pests than native species, probably due in part to
the lack of natural controls. California alone is reported to spend
$37 million fighting snail pests that attack crops. Crops affected
range from leafy vegetables to fruits which grow near the ground, such
as strawberries and tomatoes, to citrus fruits high up on trees. Since
large infestations of snails can do devastating damage, many states
have quarantines against nursery products and some other products from
infested states. Further, it is illegal to import snails (or slugs)
into the U.S. without permission from the Plant Protection and
Quarantine Division, APHIS, U.S. Department of Agriculture. The office
to write to is: Deborah Knott, USDA APHIS PPQ, Room 630 Federal
Building, Hyattsville, MD 20782. The USDA also regulates the
interstate transporting of live snails. State laws may also apply to
imports into certain states and to raising snails in a given state, so
anyone planning to raise them should check with the state's
Agriculture Department also. Your state may also want to inspect and
approve your facility.
Egg Laying
Snails are hermaphrodites. They have both male and female sex
parts, but they must mate with another snail before they lay eggs.
Some snails may act as males one season and females the next. Other
snails play both roles at once and fertilize each other. When the
snail is large enough and mature enough, which may take several years,
mating occurs in the late spring or early summer after several
page 3hours of courtship, and sometimes there is a second mating in
summer. (In tropical climates, mating may occur several times a year.)
After mating, the sperm received may be stored for up to a year, but
eggs are usually laid within a few weeks. Snails will sometimes be
uninterested in mating with another snail of the same species which
comes from a considerable distance away, such as a Helix aspersa from
northern France may be rejected by a Helix aspersa from southern
France.
Helix pomatia eggs measure about 3 mm in diameter and have a
calcareous shell and a high yolk content. They are laid in July or
August, 2 to 8 weeks after mating, in holes dug out in the ground.
(Data on how long after mating eggs are laid varies widely.) The snail
reaches its head into the hole or may crawl in until only the top of
the shell is visible, then it deposits eggs from the genital opening
just behind the head. It takes the snail one to two days to lay 50 to
80 eggs. Occasionally, the snail will lay a dozen or so more a few
weeks later. The hole is covered over with a mixture of dirt and the
slime excreted by the snail. This slime which the snails excrete to
help them crawl and to help preserve the moisture in their soft bodies
is a glycoprotein similar to eggwhite.
Fully developed baby Helix pomatia snails hatch about three to
four weeks after the eggs are laid, depending on temperature and
humidity. Birds, insects, mice, toads and other predators take a heavy
toll of the young snails. The snails eat and grow until the weather
grows cold, then they dig a deep hole, sometimes as deep as 30
centimeters, (1 foot,) and seal themselves inside their shell for the
winter. This is a response to both decreasing temperature and shorter
hours of daylight. When the ground warms up in spring, the snail
re-emerges and goes on a binge of replacing lost moisture and eating.
Helix aspersa eggs are white, spherical, about 1/8 inch in
diameter and are laid 5 days to 3 weeks after mating. (Data varies
widely due to differences in climate and regional variations in the
snails.) They are laid in a nest 1 to 1 1/2 inches deep and the
average number of eggs is about 85. Dry soil is not suitable for the
preparation of a nest, nor is soil that is too heavy. In clay soil
which becomes hard, reproduction rates may be low due to the snails'
inability to bury their eggs and the difficulty the young have
emerging after hatching. In warm, damp climates, Helix aspersa eggs
may be laid as often as once a month during the time period from
February to October, depending on the weather and region. Mating and
egg laying start when the hours of daylight increase to 8 hours or
more and continue until daylight falls below 15 hours in England. In
the United States, this schedule will be affected by longer hours of
sunlight occurring when temperatures are still too cold, but egg
laying is still stimulated by the increasing hours of daylight. If
warm enough, the eggs hatch in about 2 weeks, or about 4 weeks if
cooler. It takes several additional days for the baby snails to break
out of the sealed nest and appear on the surface. Maturity of H.
aspersa requires about 2 years in a climate like that of southern
California. In South Africa, some H. aspersa mature in 10 months, and
under ideal conditions in a laboratory, some have matured in 6 - 8
months. Most of Helix aspersa's reproductive activity takes place in
the second year of its life.
By contrast, the giant African snail, Achatina fulica, lays 100 to
400 elliptical eggs that measure about 5mm long. Each snail may lay
page 4
several such batches of eggs each year, usually in the wet
season. The eggs may be laid in holes in the ground like Helix
pomatia, or they may be laid on the surface of rocky soil, in organic
matter, or at the base of plants.
The Achatina fulica eggs hatch in 10 to 30 days, releasing snails
about 4mm long. These snails grow up to 10mm per month. After 6
months, the Achatina fulica is about 35mm long and may already be
sexually mature. Sexual maturity takes 6 to 16 months, depending on
weather and the availability of calcium. This snail lives 5 or 6
years, sometimes as many as 9 years.
Growth
Snails may eat paint or attack walls of buildings seeking
calcium. They will also eat dirt. Helix aspersa requires at least 3%
to 4% calcium in the soil (or another source of calcium) for good
growth. Most snails need more calcium in the soil than Helix aspersa.
The snail shell develops from the egg's surface membrane, so the
dimension of the newborns depends on egg size. As the snail grows, the
shell is added on to in increments. An indication of full maturity in
a snail is when the shell develops a flare or reinforcing lip at the
opening, indicating there will be no further growth of the shell.
Growth is measured by shell size, since body weight of a snail varies
and fluctuates, even in 100% humidity. Growth rate varies considerably
between individuals in each population group. So does adult size,
which is related to growth rate. The fastest growers tend to be the
largest snails.
Dryness inhibits growth and even stops activity. When it becomes
too hot and dry in summer, the snail becomes inactive, seals up its
shell and "hibernates" or "estivates" until cooler, moister weather
returns. Some snails estivate in groups on tree trunks, posts, or
walls, sealing themselves to the post or wall to use it to seal up the
shell opening.
Gathering Snails
In addition to farming snails, it is possible to gather them free
from artichoke, kiwifruit, avocado, and citrus growers in some areas,
or to pay the growers about 50 to 75 cents a pound to pick the snails
for you. In citrus groves where copper bands have been placed around
the tree trunks, the snails will crawl up the tree to feed on the
leaves but will stop when they come to the copper band and will remain
there for days. The snails gathered just below the band are easy to
pick off. Snails gathered in the wild to stock a snail farm may have a
high mortality rate as they adjust to the new conditions.
Snails which have been gathered may have consumed poison baits or
agricultural chemicals or poisonous plants such as nightshade,
therefore, they should not be used immediately. Put them in a pen and
feed them for at least 3 days to purge their system of any toxins and
to give them a chance to die if they have consumed a lethal dose. If
they are still healthy after 3 days, they should be o.k.
Farming Snails
Snail farms may be outdoors, in buildings with a controlled
climate, in plastic tunnel houses or "greenhouses," or, the breeding
page 5
and hatching may be done inside in a controlled environment and
the snails may be put in outside pens to mature. A mild climate (15-24
degrees C or 59-75 degrees F) with high humidity (75% to 95%) is best
for snail farming, though most varieties can actually stand a wider
range of temperatures. 70 degrees F. is the optimal temperature for
many varieties. When the temperature drops below 45 degrees F. (7
Celsius,) snails hibernate. Under 12 degrees Celsius (54 F) the snails
are inactive, and under 10 degrees C, all growth stops. When the
temperature rises much above 80 degrees F (28 Celsius) or conditions
become too dry, snails become dormant or estivate. Wind is bad for
snails because it speeds up moisture loss, and snails must retain
moisture.
Although snails need moisture, wet or waterlogged soil must be
drained before it is suitable for snails. Similarly, rainwater must
run off promptly. Snails breathe air and may drown. Snails need damp,
not wet environments.
Soil that is too acidic must be neutralized with lime to make it
suitable. A pH value of 5.28 has been described as optimal for Helix
snails. In addition to the pH value of the soil, calcium must be
available either from the soil or some other readily available
source, since snail shells are 97% to 98% calcium carbonate.
Enclosures for snails are usually long and thin instead of
square. This permits one to walk around and reach in to any part of
the pen without stepping on the crop. The enclosure may be a trough
with sides made of wood or block or fiber cement sheets and covered
with screen or netting to keep the snails in and birds and other
predators out. Fences or walls are usually 2 feet high plus at least 5
inches into the ground. Galvanized metal fencing helps keep some
predators out. A sprinkler system will ensure moisture when needed.
Turn it on at sunset. If turned on early in the day, snails may be
driven out into hot sunshine. Use 5mm mesh or finer for screens or
fences for snail pens. Pens containing baby snails will need a finer
mesh. A cover to keep heavy rain off may be beneficial during storms,
and shade (which may be a fine mesh screen) on warm winter days helps
keep the snails dormant. A thermometer and a hygrometer help you know
when temperature and humidity are good. Provide something the snails
can hide under during the daytime.
The vineyard snail can be contained fairly well in an open pen if
the top of the fence is curved inward in a half circle. Helix aspersa
will escape from such an open pen, so electric fences are sometimes
used to contain them. The top of the fence has two or more thin wires
2 to 4 mm apart, each one carrying the opposite charge of the wire
next to it. 4 to 12 volts may be supplied to the wires by battery or
by a transformer. When the snail crawls over a wire and touches a
second, it gets a mild shock and retracts. Another technique to keep
snails in is, instead of bending the top of the fence in a curve,
double it back in a sharp V with about a 20 degree angle. The theory
apparently is that the snail's shell hits the bent back part of the
screen before he is able to reach up and start crawling on it, so it
blocks him, and the size of the snail is automatically compensated
for. Another alternative, especially handy for solid wall enclosures,
is to use a horizontal piece of screen attached to the wall, and
projecting in a number of inches over the enclosure. The screen should
be made of a material like nylon monofilament that is moderately stiff
and springy yet easily flexible. On the inside edge of the screen,
remove the cross fibers
page 6
until you have what looks like a fringe a couple of inches wide.
As the would be escapee crawls on the bottom of the screen and moves
out onto the fringe, his weight pulls several individual fibers down.
One by one, another fiber gets away from the snail and springs back up
out of reach until the snail is dangling by a thread - which doesn't
give him enough surface area to crawl on and he falls off. Another
solution, since snails usually will not cross a copper band, is to top
the fence with a 3 inch wide copper band. The bottom of the fence must
be buried far enough in the ground that the snails don't dig under it.
Although fencing can be used for the sides of an enclosure, the
bottom, if not the ground or trays of dirt, must be a more solid
surface than screening. If a snail is put in a wire mesh bottom pen,
it will keep crawling, trying to get off the wires and onto solid,
more comfortable ground.
Snails raised in long, thin enclosures are fed regularly. Uneaten
food will rot and must be removed. An alternative method is to make
square pens with a 10 foot square garden in it with a half dozen crops
planted inside the pen. Nettles and artichokes are 2 good choices as
far as the snails are concerned. The snails choose what
they want to eat. Sprinklers are turned on for about 15 minutes at
dusk if it hasn't rained unless the snails are dormant. A disadvantage
to this method is that, if the snails are not mature at the end of the
year, replanting fresh plant crops in the pens is difficult.
Plastic tunnels make cheap, easy snail enclosures, but,
regulating heat and humidity is difficult. The tunnel will be 10 to 20
degrees warmer than the outside, and snails become dormant as the
temperature climbs above 80 degrees F.
With snails raised indoors under controlled conditions,
reproduction varies according to the geographic origin of the breeding
stock. Helix aspersa snails from Brittany seem to be better breeders
indoors than snails from some other regions. To breed snails indoors,
keep the temperature at 70 degrees F. and the relative humidity at 80%
to 90%, some sources say 95%. Another source recommends 75% humidity
by day and 95% at night. The Center for Heliculture sometimes uses
65-75% day and 85-95% humidity at night at 20 degrees Celsius. In any
event, avoid humidity higher than 95% (some say 90%) for any length of
time. Excessive humidity can be fatal to snails. Optimum temperature
and relative humidity depend on several things including what variety
and even where breeding stock was gathered. For Helix aspersa, the
optimum temperature for hatching eggs seems to be 20 degrees C at 100%
relative humidity. The second best temp./humidity combination depends
on where the snails came from and results can drop drastically to 0%
hatching at 17 degrees C and 100% humidity. Err on the side of a few
degrees warmer or a few % dryer. When maintaining 100% humidity, do
not keep the soil wet, as the eggs will absorb water, swell up, and
burst.
Data on hatching rates: Percent of eggs hatched in each of 3
groups, from snails collected in 3 different localities. Univ. of
Rennes experiment. Egg incubation in "horticultural vegetable mold."
(Leaf mold? Humus? Compost? Potting soil? Exact substance not clear.)
page 7
humidity 70% 80% 90% 95% 100%
......................................................
temperature (group #) 1 0.0% 0.3% 36.7% 21.6% 0.0%
in degrees 2 --- --- --- 10.1% 0.0%
Celsius 17 3 --- --- --- 0.0% 0.0%
.............................................................
1 14.0% 2.5% 26.0% 71.8% 91.5%
20 2 28.9% 57.4% 78.9% 74.7% 82.2%
3 15.0% 19.1% 85.8% 78.0% 96.6%
.............................................................
1 0.3% 0.0% 13.0% 15.2% 91.0%
25 2 0.8% 42.3% 52.9% 72.3% 73.2%
3 0.0% 0.0% 5.4% 33.0% 71.7%
.............................................................
1 0.0% 0.0% 0.0% 0.7% 0.0%
30 2 --- --- --- --- ---
3 --- --- --- --- ---
...and without the "horticultural vegetable mold."
17 0.0% 72.8%
20 0.0% 0.0% 30.0% 63.3%
25 --- 14.0% 13.2%
Use fluorescent lights to give artificial daylight. Different
snails respond differently to day length. Helix aspersa growth is
stimulated by long periods of daylight. 18 or more hours of light
apparently stimulates Helix aspersa growth, while less than 12 hours
inhibits it. Apparently the snail associates the long hours of light
with the peak of summer, the peak growing season. This information
conflicts with information given below for Helix pomatia. I do not
know if one of the sources made an error, or if the difference is
between the two species and their different responses. 18 hours of
daylight also appears to be optimal for breeding (mating and egg
laying,) but snails will breed in darkness.
Breeding boxes or cages can be stacked up several units high.
Water can be provided to the snails by an automatic system. Breeding
cages should have a feed trough and a water trough. Plastic trays a
couple of inches deep are adequate. Deeper water troughs increase the
chance of snails drowning in them. These trays may be set on a bed of
smooth gravel. Small plastic pots like flower pots may be filled with
sterilized dirt and then set in the gravel to give the snails a place
to lay their eggs. The pots should be 3 inches deep and about the same
diameter and filled with a loamy pH neutral soil. After eggs are laid
in a pot, it may be removed and replaced. (If the pot is set inside a
second pot, it can be easily lifted out without the gravel shifting.
After the snails have laid their eggs, the containers are put in
a nursery where the eggs hatch. The young snails stay in the nursery
for six weeks before being moved to another pen. The young snails do
best with 8 hours a day of daylight. (Longer nights mean longer
feeding time?) (This conflicts with above.) 99% of snail activity
occurs in the cool, dark nighttime, with peak activity occurring 2-3
hours after darkness begins. Young snails do best if kept with other
snails of similar size.
A method for starting Helix pomatia in boxes is described as
follows: Build wooden boxes measuring 25cm by 35cm and 25cm high. Cut
page 8
a 6cm diameter hole in the bottom and cover the hole with
plastic screening, well secured. (This hole will let excess moisture
run out.) The box lids are a frame covered with plastic screening. The
lids either must open or be removable. The boxes may be kept on
shelves to make working in them easier. Fill the boxes 1/3 full with
loose, uncompacted garden soil which has been baked to kill all
organisms, (insects, nematodes, bacteria, etc.) Use soil which does
not have fertilizer or chemicals on it. Partially cover the soil with
moss, but leave enough room for the snails to crawl around on the
dirt. Sprinkle the moss here and there with water.
Snails in the outdoor pen that are starting to make holes to lay
eggs are taken and put in the boxes, 3 per box. As soon as the snails
are finished laying their eggs, return them to the outside pen. The
soil in the boxes must not dry out. The moss must always be kept
slightly moist. Too much moisture is dangerous, however, as the eggs
may swell up and burst. The eggs hatch in about 25 days, but the baby
snails remain in the egg "shells" and then work their way out of the
nest for about 10 additional days before they appear on the moss and
the sides of the box. The ones on the wood sides of the box are in
danger of drying out and must be CAREFULLY removed and put on the
moss. The shells are very fragile at this time.
Feed the baby snails tender lettuce leaves, (Boston type, but
head type is probably just as good.) The next day you must remove all
remaining food or it will spoil. Give fresh food. Each day, remove old
food and replace with fresh. (This description does not include a
water trough, but I assume there is one. The snails ought to have
water available.)
3 weeks after the snails appear on the moss, carefully remove the
baby snails and put them in a temporary container. Carefully remove
the moss and dirt, watching for any more baby snails. Replace the dirt
and moss with fresh (sterilized - baked) dirt and fresh moss. Count
and return the snails to the box.
The young snails can be kept over winter in these boxes. Stack
the boxes in a cool room which is protected from frost. The room
should never get colder than 0 degrees Celsius (32 F) or warmer than 3
degrees C (37.4 F.) The next spring when the temperature rises above 5
degrees C (41 F,) the snails become active again. Feed them for 4
weeks. They should now average about 8mm. Move them to a pen,
carefully clean and dry the boxes, and prepare the boxes for the new
season. Helix pomatia matures in 18 months to 4 years.
A variation of this method is to let the snails lay the eggs in
the outdoor pen, then carefully transfer the eggs to the boxes. The
other steps are the same. In the pen, look for snails who have dug
holes and are in them laying eggs. The tip of their shell will be
visible. Stick a marker in the ground next to the hole. When the snail
is finished and leaves, use a garden trowel to dig up the eggs and
move them. Unfortunately, this task is difficult. The eggs tend to be
both physically damaged and covered with dirt.
Feeding
Feeding season is April through October, (or may vary with the
local climate,) with a "rest period" during the summer. Food should
not be in one small clump where there is not enough room for all the
snails to get to it. Snails eat solid food by rasping it away with
their tongues.
Snails of the same species collected from different regions may
have different food preferences. Some of the foods snails like are:
page 9
yarrow, dandelion, celery, celeriac (root celery,) henbane,
thornapple, alyssum, aster, carnation, mums, hollyhock, larkspur,
lily, nasturtium, pansy, petunia, phlox, sweet-pea, zinnia, rose,
chive, leek, elder, nettle, carrot, camomile, bindweed, sorrel, peas,
radish, turnip, oats, barley, wheat, mulberry, mountain ash, magnolia,
California boxwood, hibiscus, cauliflower, almost any cabbage variety,
clover, spinach, parsley, cress, kale, onion greens, beans, pumpkins,
rape, ripe pears, ripe cherries, fruit and leaves of apple, apricot,
citrus, peach, plum, nightshade berries, thistle, raw or cooked
potatoes, artichoke (a favorite,) lettuce (liked, and makes good
snails,) tomatoes (well liked,) and cucumbers (a favorite snail food.)
Sweet lupines are eaten, but bitter lupines and other plants with high
quinolizidine alkaloids are rejected. Snails also tend to avoid plants
which produce other defensive chemicals, defensive stem hairs, etc.
Juicy leaves and vegetables are usually preferred to dry ones.
Snails may be fed vegetable trimmings, damaged fruit, and cooked
potatoes, but the uneaten food will quickly spoil and must be promptly
removed. Bran may be fed wet or dry bran may be sprinkled over leafy
vegetables. Wheat bran may be about 20% of the diet while fruit and
vegetable material is about 80%. Some growers use oats, corn meal,
soybean meal, or chicken mash. Laying mash will provide calcium, as
will crushed oyster shells. Snails may also eat materials such as
cardboard, (but don't purposely feed it to them,) and many
have escaped during shipment by eating the package. Snails may
sometimes eat food equal to 10% and occasionally as much as 20% of
their body weight in 24 hours. If active snails are deprived of food,
they will lose over one third of their weight before starving to
death, a process that takes 8 to 12 weeks. Estivating snails can go
much longer.
Calcium, if not available in the soil, should be fed at least
once a week. It should not contain harmful salts or be so alkaline as
to burn the snails. Calcium may be mixed with wet bran or mashed
potatoes and fed on a pan, which will keep the leftover food from
rotting on the ground.
Diseases and Pests
Basic common sense hygiene may prevent the spread of disease or
otherwise improve the health and growth rate of snails. Also be aware
that snails may be attacked by parasites, nematodes, trematodes,
fungi, and microarthropods, and such problems can spread rapidly when
snail populations are dense. The bacterium Pseudomonas aeruginosa
causes intestinal infections which can spread rapidly when the
population is crowded. Predators to watch out for include rats, mice,
skunks, weasels, birds, toads, lizards, some insects such as some
beetle and cricket varieties, some types of flies, centipedes, and
even certain cannibalistic snail varieties (such as Strangesta
capillacea.)
Population Density
6 to 8 fair sized snails per square foot, or about 4 large Helix
pomatias, is about as dense as you should pack them in a pen, or
figure 1 kilogram per square meter, (about .2 pounds of snail per
square foot,) which automatically compensates for the size of the
page 10
snails. If you want them to breed, best results will occur with
not more than 8 snails per square meter, (.8 snails per square foot,)
Some sources state that, for Helix pomatia to breed, .2 to .4 snails
per square foot is the maximum. Snails tend not to breed when packed
too densely or when the slime in the pen accumulates too much. The
slime apparently works like a pheromone and suppresses reproduction.
On the other hand, snails in groups of about 100 seem to breed better
than when only a couple of snails are confined together. Perhaps they
have more potential mates to chose from. Snails in a densely populated
place grow more slowly even when food is abundant, and they have a
higher mortality rate too. These snails then become smaller adults who
lay less clutches of eggs, less eggs per clutch, and the eggs have a
lower hatch rate. Crowding snails is false economy.
Within the same snail population and under the same conditions,
some snails will grow faster than others. Some will take twice as long
to mature. This may help the species survive bad weather, etc. in the
wild, but a snail farmer should obviously select only the biggest and
fastest growers for breeding stock. By selecting only the largest, the
average size of the snail can be significantly increased in only a
couple of generations.
Snails like hiding places. Plastic soil drainage pipes from the
local garden center, split in two lengthwise, and stacked one layer
this way, next layer that way will provide shelter and will increase
the number of snails you can put in the pen by 50%
Put the breeding snails in the breeding pens in April or early
May. Feed until mid June when mating begins and the snails stop
feeding. Feeding resumes after the eggs are laid.
Shipping
Live snails may be shipped, (laws permitting,) while dormant,
from late Fall to early March. Put them in a container packed in ice
to keep the temperature near (but not below!) freezing to keep the
snails dormant. When the weather warms up and the snails are active,
they can not be packed so closely in cartons. As live animals, they
must be handled humanely. Some sources say live snails (Helix pomatia)
should not be shipped after June begins, as they no longer have good
flavor.
Snails tend not to eat food during shipping. No food should be
given, as it will spoil and may make the snails sick or die. It is
best to stop feeding the snails about 3 days before they are shipped
so that the "dirt" will be cleaned out of their digestive tract and
will not dirty up the snails during shipping. Water should be
available to the snails during these last 3 days.
Shipping cartons must have air holes, preferably screened to
prevent injury to the snails. Care must be taken not to injure snails
with wires or staples when closing the carton. Also remember, snails
can push upward against a barrier with a force equal to several times
their own weight. With a large number of snails pushing, lids may pop
off and even nails may come loose and your cargo of escargot may go.
Turning Snails into Escargot
Nutritional values for snails may vary slightly, but snails have
about 300 calories per pound of meat, are about .5% to .8% fat, 1.5%
minerals, 84% water and about 12% to 16% protein. 9 of the 10 amino
page 11
acids needed by humans are in snail protein. Dehydrated
Achatina meal contains 61% protein. How the snails are handled and
prepared can radically alter this data.
Canned snails are washed, steamed, shelled, then washed in a
vinegar and water solution before being canned. Producing a quality
canned product is somewhat tricky. To prepare live snails for cooking,
remove the membrane, if any, over the shell opening. Soak the snails
in enough water to cover them, water to which you have added 1/2 cup
salt or 1/4 cup vinegar for every 50 snails (large, I assume.) Change
the water several times during the 3-4 hour soaking. Rinse in several
waters or under running water until the slime is removed. Put in cold
water and bring to a boil. Boil 8-10 minutes, then drain and plunge
the snails into cold water. Drain. With a needle or small fork, pick
the snails out of their shells. Remove the intestine and cut off all
black parts. (Some cooks also cut off the head, tail, and all
"cartilage or gristle.") Prepare as according to your recipe. An
alternate method is, wash the snails well. (Obviously, don't use
soap.) Drop into boiling salt water (to which you may add lemon juice
and/or herbs,) and cook until the snails can be easily removed from
their shells, about 10-15 minutes. Drain and rinse.
The giant African snail is prepared by breaking away the shell,
then cutting the foot away from the rest of the body. The traditional
way to remove the slime is to rub wood ashes on the snail, then wash
the snail (or part of the snail) under running water, then repeat
until the slime is removed. Substances like flour (to which you may
add salt and vinegar) can be substituted for ashes. The foot is then
cut up into convenient sized pieces. The left over visceral mass can
be dehydrated and crushed up with the shell and mixed in poultry feed
to constitute 10% of the feed. Another source says put the live snails
in boiling water for 30 minutes to kill them and to make removal from
the shell easy. A large quantity of mucous will be released by the
snails during boiling. Data varies, but 28% to 46% of the live weight
of Achatina is shell.
Anyone who wishes to raise snails should expect to do some
experimentation by trial and error to find what works best in their
specific situation. Expect a few problems. Raising snails is not yet
an exact science.
Persons and Organizations Who Have an Interest in Snails:
(information as of August, 1987)
Associazione Nazionale Elicicoltori (ANE) (The Italian Snail Farmer's
Association), Via Vittorio Emanuele 103, 12062 Cherasco (CN), Italy
Ralph Tucker, president of the Snail Club of America, 187 North Duke
Ave., Fresno, California 93727. (900 members in 50 states and 24
foreign countries.) Conducts seminars on raising and marketing
snails. Publishes a newsletter, "The Artichoke Leaf." Mr. Tucker sees
snail farming as a food source to feed the world's hungry.
Tracy Brash and Michael Beyries of Enfant Riant, P.O. Box 357,
Petaluma, California 94953. They raise and purchase snails and also
sell them live and canned, having their own (state) government
approved and inspected cannery. Don't call or write to ask them how.
As a commercial firm, they don't have time to answer a lot of
page 12
inquiries. To quote Mr. Brash, "People call us all the time
asking how we raise our snails - like we are supposed to just give
away all our secrets." Enfant Riant has spent several years and
hundreds of thousands of dollars developing their techniques. Enfant
Riant DOES NOT ANSWER INQUIRIES ABOUT SNAIL FARMING.
Frances Herb, 1213 Stockton Street, St. Helena California 94574. Ms.
Herb has raised snails for a number of years and has prepared a 17
page publication on how to raise them which she mails out for $5.
Elton Geist, P.O. Box 914, Colfax, California 95713 Performs
research on raising snails.
Dr. Ted W. Fisher 34443 Fisher Lane, Hemet, California 92343.
Entomologist at the University of California, Riverside. Does research
on raising snails and biological control of snails.
Institut National de la Recherche Agronomique (INRA), 149 Rue de
Grenelle, 75007 Paris, France, supports research on snail farming at
the University of Rennes in western France at the Centre Helicicole du
Magneraud, (Center for Heliculture.) Does not encourage public
inquiries about snail farming. The director of snail farming research,
Jean-Louis Vrillon points out that, at our present state of knowledge,
snail colonies are prone to be wiped out by mysterious disasters, and
the INRA does not want to be blamed for the bankruptcy of any
entrepreneurs.
Alain Chatillon, Rennes-le-Chateau, France (complete address not
known.) Promotes snail eggs as an alternative to caviar. His method
for processing the eggs is a closely guarded secret.
USDA APHIS PPQ, Room 630 Federal Building, Hyattsville Maryland 20782
(Regulates interstate transport and importing of snails.)
Some Books and Articles on Snails: (NAL = National Agricultural
Library)
Die Weinbergschnecke NAL call number 437 N552
by Gunther Nietzke
Verlag Eugen Ulmer, Stuttgart, 1963, 112 pages (In German)
El Caracol; Cria y Produccion NAL call number SF 597 .S6V5 1983
by I. Viladevall Pedrosa
Editorial Aedos, Barcelona, l983, 147 pages (In Spanish)
Elicicoltura Pratica NAL call number SF597 .S6D4
by Cesare Della Pieta
Ottaviano, Milano, 1981, 200 pages (In Italian)
Guida Completa All'allevamento Delle Chiocciole NAL call number
by Francesco Marasco and Corrado Murciano SF597 .S6M37
De Vecchi Editore, Milano, 1981, 124 pages (In Italian)
L'allevamento Redditizio Delle Lumache NAL call number
by Fausta Mainardi Fazio SF597 .S6M3
De Vecchi Editore, Milano, 1980, 71 pages (In Italian)
page 13
L'elevage Des Escargots NAL call number SF597
.S6R64
by Michel Rousselet
Le Point Veterinaire, Maisons-Alfort, 1978, 106 pages (In French)
L'escargot Et Son Elevage NAL call number SF597 .S6G33
by Quentin Garnier
Editions Lechevalier, Paris, 1978, 149 pages (In French)
Les Escargots NAL call number QL 430.5 .H4C3
by Jean Cadart
Editions Lechevalier, Paris, 1975, 433 pages (In French)
Principi Di Elicicoltura NAL call number SF597 .S6A9 1979
by Gianni Avagnina
Edagricole, Bologna, 1979, 83 pages (In Italian)
Explotacion y Cria del Caracol NAL call number SH373 .J6
by Matias Josa Artes
Editorial Sintes, Barcelona, 1970, 91 pages (In Spanish)
Edible Land Snails in the United States
by Lola T. Dees
Resource Publication 91, U.S. Dept. of the Interior, 1970 8 pages
Raising Snails for Food
(17 typewritten pages on how to, by someone who has done it for
several years.) For a copy, send $5 to:
Frances Herb
1213 Stockton Street
St. Helena, California, 94574
Snail Farming Research not owned by NAL (on order)
Associazione Nazionale Elicicoltori
Via Vittorio Emanuele 103
12062 Cherasco (CN), Italy (English translation)
Systems for Snail Farming
by Hans Pos
New Zealand Farmer, July 12, 1984, pages 93-96
Snail Farming for Top Profits
by Edward Difarn
Border Business Bureau, London, 1984, 44 pages
Variation in Growth Rate as an Ecological Factor in the Landsnail
Cepaea nemoralis NAL call number QL430.5 .H406
by Lucy Oosterhoff
E. J. Brill, Leiden, 1977, 132 pages (in English)
The Brown Garden Snail
by G. W. Dekle
Entomology Circular #83, Florida Dept. of Agriculture, Div. of Plant
Industry, April 1969 2 pages
The Protein Rich Giant African Snail
by P. D. Srivastava
Indian Farming, December 1977, pages 33-34
page 14
Conversions:
Farenheit Celsius Milimeter (mm) Inches
32 = 0 6 = 1/4
41 = 5 10 = .4
50 = 10 13 = 1/2
59 = 15 25 = 1
68 = 20
70 = 21
77 = 25
[]<>[]<>[]<>[]<>[]<>[]<>[]<>[]
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