Animal Diversity Web

Ge­o­graphic Range

The north­ern dis­tri­b­u­tion bound­ary of Cepaea nemoralis is in Scot­land and south­ern Scan­di­navia. The range ex­tends south to the Iber­ian Penin­sula and Croa­tia in the south. Ca­paea nemoralis is found in the west­ern and east­ern coasts of both Ire­land and the UK, Bel­gium, and France. The east­ward dis­tri­b­u­tion ex­tends to the north­west­ern areas of Poland. This species was in­tro­duced in south­east­ern Poland, where it cur­rently thrives. Cepaea nemoralis was in­tro­duced into North Amer­ica dur­ing the nine­teenth cen­tury and is cur­rently found in Vir­ginia, New York, On­tario, and Mass­a­chu­setts. (Bel­lido, et al., 2002; Brus­sard, 1975; Cain, 1968; Chang and Emlen, 1993; Jor­daens, et al., 2006; Ozgo, 2005; Richards and Mur­ray, 1975)

• Biogeographic Regions
• nearctic
  • introduced
• palearctic
  • native

Habi­tat

Cepaea nemoralis is found in habi­tats rang­ing from hedgerows to down­land turf and from beech woods to sand dunes near the sea. This species is also found through­out grasses and herbs. A rel­a­tively small amount is found in Mar­ram grass. Un­banded and yel­low C. nemoralis are mostly found in open habi­tats. Colonies with a green back­ground have a high pro­por­tion of yel­low C. nemoralis. Yel­low C. nemoralis can also be found in shaded areas and banded shells of this species are found in areas of hedgerows and mixed rough herbage. In areas where the type of land is dis­con­tin­u­ous, branded C. nemoralis are found. In South­east­ern Poland, where C. nemoralis has been in­tro­duced, the species is found in urban en­vi­ron­ments where it in­hab­its gar­dens, or­chards, ceme­ter­ies, hedgerows and other veg­e­ta­tion made up of herbs. In the hot and dry months of the sum­mer, C. nemoralis is also found in tall plants and plants with large leaves or stems. Two of these plants in­clude gold­en­rod and Cen­tau­rea. Dur­ing hi­ber­na­tion C. nemoralis are found un­der­ground on land and un­der­wa­ter where they can sur­vive for 2-3 weeks. (Cain, 1968; Cameron, 2001; Chang and Emlen, 1993; Good­hart, 1962; Ozgo, 2005; Richards and Mur­ray, 1975; Shep­pard, 1951)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• savanna or grassland

• Other Habitat Features
• urban

Phys­i­cal De­scrip­tion

Cepaea nemoralis has a yel­low, pink, or brown shell. The shell con­tains as many as five dark bands (each 360 de­gree rev­o­lu­tion con­sti­tutes one band). The shells are made up of dif­fer­ent lay­ers. The outer layer (pe­rios­tracum) is made up of con­chi­olin and the layer di­rectly layer is much thicker and is com­posed of cal­cium car­bon­ate. Cal­cium is an im­por­tant com­po­nent of the shell and it is an im­por­tant fac­tor that de­ter­mines the shell strength. Cal­cium con­cen­tra­tions vary from 319 to 359 mg/g. The shell strength, mea­sured in New­tons re­quired to break it, varies from 35 to 63 N. Cepaea nemoralis shell thick­ness varies from 0.17 to 0.21 mm. The dry weight of the shell varies from 0.43 to 0.72 g. The shell vol­ume mea­sures any­where from 2230 to 3012 cubic mm. (Cameron, 2001; Jor­daens, et al., 2006; Ozgo, 2005; Richards and Mur­ray, 1975; Richard­son, 1975a; Richard­son, 1975b; Shep­pard, 1951; Williamson and Cameron, 1976)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry
• polymorphic

• Sexual Dimorphism
• sexes alike

• Range mass

  0.72 (high) g

  0.03 (high) oz

• Range basal metabolic rate

  0.014 to 0.251 cm3.O2/g/hr

• Average basal metabolic rate

  0.134 cm3.O2/g/hr

De­vel­op­ment

In Eu­rope, from 30-80 eggs (2.3-3.0 mm in di­am­e­ter) are laid and hatch in 15-20 days. High tem­per­a­tures and low hu­mid­ity re­duce the snail's ac­tiv­ity and there­fore in­hibits growth rate. Cepaea nemoralis can form the peri­s­tome lip, which in­di­cates it is an adult, in one ac­tive sea­son. Ju­ve­niles may take to three years to de­velop into adults.

The color vari­a­tion in the shells of Cepaea nemoralis is de­ter­mined ge­net­i­cally by al­lelic se­ries. Yel­low shell al­le­les are re­ces­sive to pink shell al­le­les, and both yel­low and pink shell al­le­les are re­ces­sive to brown shell al­le­les. The un­banded shell al­lele is dom­i­nant to banded. (Gilliland, 2005; Ozgo, 2005; Schultes, 2011)

Re­pro­duc­tion

Cepaea nemoralis is her­maph­ro­ditic and mates more than once. A mat­ing part­ner for C. nemoralis is ran­dom, ac­cord­ing to color, size and band­ing pat­terns. The snails can store sperm for long pe­ri­ods of time. Each in­di­vid­ual C. nemoralis may pro­duce off­spring from sev­eral mat­ings in each brood. The av­er­age num­ber of mates per brood is two. Cross fer­til­iza­tion is oblig­a­tory.

The off­spring of each C. nemoralis is di­vided into a num­ber of broods that is pro­duced over a pe­riod of months or even years. This makes it un­likely that the fates be­tween dif­fer­ent broods will mimic each other. Each brood con­sists of ge­netic con­tri­bu­tions from one fe­male par­ent and two male par­ents. This re­duces the de­pen­dence of sin­gle par­ents for sur­vival within a whole brood unit. This sys­tem of mul­ti­ple mat­ing and sperm stor­age pro­tects or­gan­isms that are min­i­mally mo­bile from com­plete fa­tal­ity within a gene pool.

Courtship of C. nemoralis is elab­o­rate. A cal­care­ous dart is jabbed into a po­ten­tial part­ner be­fore mat­ing be­gins. In order to pre­vent ac­ci­den­tal mat­ing be­tween C. nemoralis and a closely re­lated species, Cepaea hort­en­sis, the two species have dif­fer­ent darts. ("Gas­tropods", 1989; Mur­ray, 1964)

• Mating System
• polygynandrous (promiscuous)

The breed­ing in­ter­val of Cepaea nemoralis runs from April through Oc­to­ber. The rel­a­tive sea­sons are spring, sum­mer and the be­gin­ning of the fall. The num­ber of off­spring per brood is around 23. Eggs are laid si­mul­ta­ne­ously in a dug nest in soil. The snail's foot is used to cre­ate a cav­ity in soil for lay­ing eggs. The lay­ing of the eggs can take up to three days and when com­plete, its foot is used again to cover the nest.

The av­er­age num­ber of hatched young per year is 33. The eggs of one brood may sur­vive or die as a unit; how­ever, once they hatch, the in­di­vid­ual's sur­vival is not cor­re­lated to the rest of the brood. High tem­per­a­tures and low hu­mid­ity re­duce the snail's ac­tiv­ity and there­fore in­hibits growth rate and egg pro­duc­tion. ("Gas­tropods", 1989; Chang and Emlen, 1993; Good­frien, 1983; Good­hart, 1962; Green­wood, 1974; Mur­ray, 1964; Wolda, 1967)

• Key Reproductive Features
• seasonal breeding
• sequential hermaphrodite
• sexual
• induced ovulation
• fertilization
  • internal
• oviparous
• sperm-storing
• delayed fertilization

• Breeding interval

  This species breeds 1 to 2 times yearly.

• Breeding season

  Breeding season is from April to October.

• Average number of offspring

  23

• Range age at sexual or reproductive maturity (female)

  1 to 2 weeks

• Range age at sexual or reproductive maturity (male)

  1 to 2 weeks

Cepaea nemoralis pro­duces eggs at the same time and are laid in nest they dig and cover up with soil. Be­yond hatch­ing, there is no parental care. (Mur­ray, 1964)

• Parental Investment
• male parental care
• female parental care
• pre-fertilization

Lifes­pan/Longevity

Cepaea nemoralis may live up to six years in the wild, but this is un­com­mon be­cause of pre­da­tion. In cap­tiv­ity, they may live up to 10 years. The av­er­age lifes­pan of C. nemoralis is 2.3 years. The sur­vival rates of the young greatly dif­fers and can range any­where from 0.3 to 0.7. How­ever, in most cases, the rate is closer to 0.3. It de­pends on the re­gion and the tem­per­a­ture. (Good­hart, 1962; Green­wood, 1974; Jor­daens, et al., 2006)

• Range lifespan
  Status: wild

  6 (high) years

• Average lifespan
  Status: wild

  2.3 years

• Range lifespan
  Status: captivity

  10 (high) years

• Average lifespan
  Status: wild

  2.3 years

Be­hav­ior

Cepaea nemoralis has dif­fer­ent be­hav­iors through­out dif­fer­ent times of the year. In the sum­mer, the species moves to an el­e­vated and shaded part of veg­e­ta­tion dur­ing the morn­ings. The el­e­va­tion pro­vides C. nemoralis with lower tem­per­a­tures and the shade from veg­e­ta­tion pro­vides pro­tec­tion from the sun's rays. In the spring and fall, C. nemoralis does not ex­hibit this climb­ing be­hav­ior. This is be­cause the cli­mates of the spring and fall are milder than that of the sum­mer. In the spring, there is a high de­gree of food scarcity which leads to C. nemoralis pre­fer­ring food over shel­ter. In the fall, how­ever, C. nemoralis dis­plays pref­er­ence for shel­ter rather than food be­cause of the rel­a­tive food abun­dance.

Cepaea nemoralis lives amongst each other with a den­sity range of 0.5 to 3.5 adults per square meter. The av­er­age den­sity is 1.4 adults per square meter. Pop­u­la­tions of any group of C. nemoralis range any­where from 380 to 14,000 total snails. A higher pop­u­la­tion usu­ally in­di­cates a higher adult den­sity (per square meter).

Ca­paea nemoralis, on av­er­age moves 3.018 me­ters per year or 0.826 cm per day. (Chang and Emlen, 1993; Good­hart, 1962; Green­wood, 1974)

• Key Behaviors
• terricolous
• nocturnal
• motile
• sedentary
• hibernation
• colonial

Com­mu­ni­ca­tion and Per­cep­tion

Cepaea nemoralis is able to re­spond to painful and non-painful stim­uli. Dur­ing the night, C. nemoralis feels more pain. Cal­cium chan­nels are in­volved in the reg­u­la­tion of neu­ronal func­tions in mol­lusks in a man­ner like ver­te­brates. Sim­i­lar in­ter­me­di­ary mes­sen­ger sys­tems also exist be­tween Cepaea and ro­dents.

Cepaea nemoralis pre­dom­i­nantly moves in an up­wind di­rec­tion. They first ran­domly move in any di­rec­tion be­fore fol­low­ing the up­wind stream. The de­ci­sion to move up­wind is made when the odor of fa­vored foods is de­tected. In­ter­ac­tions be­tween C. nemoralis exist. As the num­ber of in­di­vid­u­als within a colony in­creases, there is a de­cline in ju­ve­nile growth rates and birth rates. Lim­ited re­sources is not the ex­pla­na­tion be­cause even in areas of nor­mal com­pe­ti­tion, there is still growth rate and birth rate de­clines. This in­di­cates that there is ei­ther a chem­i­cal or be­hav­ioral type of com­mu­ni­ca­tion within the species that is re­spon­si­ble for the dec­li­na­tion. (Good­frien, 1983; Kava­liers and Os­senkopp, 1991; Williamson, et al., 1976)

• Communication Channels
• visual
• tactile
• chemical

• Perception Channels
• visual
• infrared/heat
• tactile
• chemical
• magnetic

Food Habits

Cepaea nemoralis prefers to eat dead plant ma­te­r­ial rather than fresh. They also pre­fer to eat herbs rather than grasses. Adult C. nemoralis show greater se­lec­tiv­ity in their eat­ing habits than the ju­ve­niles, al­though they eat some grasses while ju­ve­niles do not. They eat Po­terium san­guisorba and Leontodon hispidus. Lotus cor­nic­u­la­tus and Ur­tica dio­cia are ex­am­ples of rarely con­sumed greens. Cepaea nemoralis avoid vetch, shrub and grass in their diet. Re­mains of ants, bee­tles, spi­ders, mites, spring­tails and aphids are found in the diet of C. nemoralis, but these are prob­a­bly the re­mains that were eaten along with greens and herbs.

In a colony that is as dense as 5 adults per square meter, the mean an­nual bio­mass con­sumed is 1.03 g per square meter. A large C. nemoralis can eat 125 mg of food per week, mean­ing a daily con­sump­tion rate of 59.5 mg of food per 1 g of dry tis­sue weight of the snail. Cepaea nemoralis re­lies on large lumps of food and its hy­drolytic en­zymes in its gut for nu­tri­tion. Vi­t­a­mins A and B and some sterols are re­quired com­po­nents of C. nemoralis nu­tri­tion. Adults re­quire sitos­terol, a plant sterol. ("Gas­tropods", 1989; Chang and Emlen, 1993; Richard­son, 1975b; Williamson and Cameron, 1976; Williamson, et al., 1976)

• Primary Diet
• herbivore
  • folivore
  • frugivore
  • lignivore

• Animal Foods
• insects

• Plant Foods
• leaves
• wood, bark, or stems
• fruit
• flowers

Pre­da­tion

Birds, mice, and rats are the most sig­nif­i­cant preda­tors of Cepaea nemoralis. In Eu­rope, the most com­mon preda­tor of C. nemoralis is song thrushes. Preda­tors feed on snails by crack­ing the shells on nearby hard ob­jects or with the use of their teeth.

Other preda­tors of C. nemoralis in­clude the rook, the brown rat, hedge­hogs, moles, field mice, Sorex, rab­bits, and mag­gots. Phorid flies are par­a­sitic and con­sume C. nemoralis.

Anti-preda­tor adap­ta­tions of C. nemoralis in­clude the com­plex­ity of color and bands on shell vary­ing with the com­plex­ity of the land­scape, known as back­ground match­ing. Brown shelled C. nemoralis are found in land­ward parts which are gen­er­ally com­plex land­scapes. Un­banded shells are found in the most pit­ted areas. The great­est com­plex­ity in the vari­a­tion of shell col­ors and whether or not the shells are un/banded cor­re­lates with the amount of en­closed spaces such as pits that serve as am­phithe­aters for other or­gan­isms. Song Thrushes, a main preda­tor of C. nemoralis, preys on shells that are dis­tin­guish­able from the en­vi­ron­ment.

An­other anti-preda­tor adap­ta­tion of C. nemoralis is shell thick­en­ing. Thick­en­ing of the shell pre­vents the abil­ity of a preda­tor to crush the shell. It also in­creases the "han­dling time" of the snail. In­creas­ing han­dling time makes C. nemoralis less en­er­get­i­cally re­ward­ing prey. Crush­ing re­sis­tance pos­i­tively cor­re­lates with cal­cium con­cen­tra­tion. (Cain, 1968; Cook, 2008; Cur­rey, 1964; Good­hart, 1962; Jor­daens, et al., 2006)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Song thrush, Turdus ericetorum
  • Rook, Corvus frugilegus
  • Brown rat, Rattus norvegicus
  • Hedgehog, Erinaceus europaeus
  • Moles, Talpidae
  • Field mouse, Apodemus sylvaticus
  • Rabbits, Leporidae
  • Maggots
  • Phorid flies, Phoridae

Ecosys­tem Roles

Phorid flies are par­a­sitic on C. nemoralis. (Good­hart, 1962)

• Ecosystem Impact
• biodegradation

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Cepaea nemoralis dis­play a sig­nif­i­cant amount of poly­mor­phism in their shells. This poly­mor­phism has been the sub­ject of many evo­lu­tion­ary stud­ies in Eu­rope. (Brus­sard, 1975)

• Positive Impacts
• research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse af­fects of Cepaea nemoralis on hu­mans.

Con­ser­va­tion Sta­tus

Cepaea nemoralis is listed as "least con­cern" in the Czech Re­pub­lic. It is not spe­cially listed by any other coun­tries or or­ga­ni­za­tions. (Ju­rick­ova, et al., 2001)

• IUCN Red List

  No special status
  More information

• IUCN Red List

  No special status
  More information

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Sami Ham­moud (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor, Renee Mul­crone (ed­i­tor), Spe­cial Pro­jects.

Ref­er­ences

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