BBC Focus - 03.2020

DISCOVERIES

MARINE BIOLOGY

Cuttlefish skimp on lunch

if shrimp is for dinner

Whencuttlefishknowthattheir

favouritefoodwillbe on the menuat

dinnertime, they’lleat lessfor lunch,

accordingto new

researchcarriedout

at the Universityof

Cambridge.

Cuttlefishare a type

of cephalopodmollusc

andtheyhavea wide

dietthatincludes

crab,fish,squidand

shrimp,but theyshow

definitepreferencesfor

particularfoods.After

establishingthatshrimp

wasthe favourite

foodof European

commoncuttlefish(Sepiaofficinalis),

the researchersfoundthatwhenthey

reliablygavethe cuttlefisha mealof

shrimpin the evening,they’deat fewer

crabs when they were offered during

“Thiscould

offernew

insightinto

whencomplex

cognitive

ability

evolved”

In numbers

1

/

3

TheproportionofUK

doctorsthoughttobe

stressedorburntout,

accordingtoa study

publishedinTheBritish

Medical Journal.

2.

BILLION YEARS

Theageof theYarrabubba

meteoritecraterinWestern

Australia,asestimatedbya

team atCurtinUniversity.

7

YEARS

Thelengthoftimeanolm,

a smallcave-dwelling

salamander,stayed

motionlessinBosnia-

Herzegovina,asfoundby

Eštvšs Lor‡nd University.

the day.Whenthe shrimpdinnerswere

onlyprovidedat random,the cuttlefish

wouldeat morecrabsduringthe dayas

theycouldnot predictif theirfavourite

foodwouldbe availablelateron.

“It wassurprisingto see howquickly

the cuttlefishadaptedtheireating

behaviour– in onlya fewdaysthey

learnedwhethertherewaslikelyto

be shrimpin the eveningor not.This

is a verycomplexbehaviourandis

onlypossiblebecausetheyhavea

sophisticatedbrain,”saidPauline

Billard,whotookpartin the research.

Whencuttlefishhatchout,they

alreadyhavea largecentralnervous

systemandare ableto learnfrom

a youngage.Theyare capableof

respondingto theirenvironment

in a flexiblefashion,andcan adapt

theirhunting,matingandbehaviour

strategiesto ensurethe bestpossible

outcomes. Inthisstudy,theyproved

thattheycouldadjust

theirforagingbehaviour

on a dayto daybasis

to guaranteethatthey

wereeatingenough,but

alsonot missingout on

theirfavouritefoods.

In evolutionary

terms,cephalopods

splitfromthe vertebrate

lineagearound 550

millionyearsago,yet

theirnervoussystems

are remarkablysimilar.

Thesefindingscould

offernewinsight

intowhencomplex

cognitiveability

evolved.

Cuttlefish

willskimpon

lunchif they

knowtheir

favourite

meal,shrimp,

is for dinner

It’scommonlybelievedthatone-thirdofall

foodis thrownaway,butthis“grossly

underestimatestheextentoffoodwasted,”

accordingtoresearchersin theNetherlands.

Theyfoundfoodwastagetoberising

rapidlyfromthosewitha dailyspendof

£5.20 or more. The ‘one-third’ figure was

firstestimatedin 2005bytheFoodand

AgricultureOrganizationoftheUnited

Nations(FAO),whofoundfoodwastetobe

214 caloriesperperson,perday.However,

thisdidn’taccountfordifferencesin income

andbuyinghabits.Thenewstudyestimates

it to be almost double, at 527 calories a day.

UPTOTWO-THIRDSOFALLFOOD MAY BE WASTED AND THE RICH ARE

THE WORST OFFENDERS