BBC Wildlife - UK (2020-08)

Snails: Angus Davison/University of Nottingham

FINDOUTMORE

Biology Lettersbit.ly/3gdqGJd

Howararele-handedmolluscnamed

Jeremyfoundfameandadvanced

scientic understanding.

BIOLOGY

D I D Y O U

KNOW?

Left-handedsnails

aremorelikelyto

surviveattackbysnail-

eatingPareassnakes.

Thisisduetothe

arrangementofthe

serpents’ teeth.

Shellebrity snail

Whenit comestoshell

coils,oppositesdon’t

attract.Below:Jeremy

with ospring.

W

hilemostanimalsare

superficiallysymmetrical,there

arealmostalwayssubtledifferences

betweenleftandright:thearrangement

oftheinternalorgans;whichhandone

preferstoholda penwith;thedirection

inwhicha shellcoils.Sowhena rare

left-handedsnailpoppedupina London

garden,it gavescientistsa unique

opportunitytostudytherootofthis

mysteriousphenomenon,witha lot of

helpfromcitizenscientists.

“I’dnevercomeacrossa left-

coilinggardensnailbefore,”says

AngusDavison,a Universityof

Nottinghambiologist,who

tookcustodyoftheLondon

specimen.Themajority

ofgardensnails

areright-handed,

meaningtheirshells

coilina clockwise

direction.Onlyabout

onein40,000snails

are ‘lefties’.

Partofthereasonfortheir

rarityis thatthearrangement

oftheirshellsandgenitalia

makesmatingwitha right-

handeralmostimpossible.

“Tostudythegenetics,we

neededtofindit a left-handed

mate,”saysDavison.“There

wasa eurekamomentwhen

werealisedwecouldgetthe

publictohelpus.”

Jeremy,asthesnailwasnamed(after

thatotherfamouslefty,MrCorbyn),found

him/herself(snailsarehermaphrodites)

thrustintothelimelightonsocial

mediaandevenRadio4’s

To d a yprogrammein

anattemptto inspire

thesearch.

“Itactually

worked,”says

Davison.Leftieswere

soonarrivingfrom

amateurnaturalists

across Europe.

“AtwhichpointI was

committedtoa snailbreeding

programmeforthreeyears.”

Davisonhasnow

publishedtheresultsofthose

endeavours,whichshows

littlegeneticinfluenceon

thedirectionofcoiling.In

whichcase,whatis it that

makesthelikesofJeremystandout

fromthecrowd?Davisonbelievesit’s

duetoanunlikelyaccidentearlyinthe

snail’sdevelopment.

Helikensit toanold-fashionedspiral

telephonelead:“Stretchit outfullyand

releaseit,andit cancoilupagaininthe

oppositedirection.”

Davisonis keentodigdeeperstill.

Andforthat,he’llneedmoreleftysnails:

“Atveryleast,pleasetakea lookatyour

snailsbeforeyouchuckthemover the

garden wall.”Stuart Blackman

24 BBC Wildlife August 2020

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