BBC Science Focus - 03.2020

DISCOVERIES

MARINE BIOLOGY

Cuttlefish skimp on lunch

if shrimp is for dinner

When cuttlefish know that their

favourite food will be on the menu at

dinnertime, they’ll eat less for lunch,

according to new

research carried out

at the University of

Cambridge.

Cuttlefish are a type

of cephalopod mollusc

and they have a wide

diet that includes

crab, fish, squid and

shrimp, but they show

definite preferences for

particular foods. After

establishing that shrimp

was the favourite

food of European

common cuttlefish (Sepiaofficinalis),

the researchers found that when they

reliably gave the cuttlefish a meal of

shrimp in the evening, they’d eat fewer

crabs when they were offered during

“Thiscould

offer new

insight into

when complex

cognitive

ability

evolved”

In numbers

1

/

3

Theproportion of UK

doctors thought to be

stressed or burnt out,

according to a study

published inThe British

Medical Journal.

2.

BILLION YEARS

The age of the Yarrabubba

meteorite crater in Western

Australia, as estimated by a

team at Curtin University.

7

YEARS

The length of time an olm,

a small cave-dwelling

salamander, stayed

motionless in Bosnia-

Herzegovina, as found by

Eštvšs Lor‡nd University.

the day. When the shrimp dinners were

only provided at random, the cuttlefish

would eat more crabs during the day as

they could not predict if their favourite

food would be available later on.

“It was surprising to see how quickly

the cuttlefish adapted their eating

behaviour – in only a few days they

learned whether there was likely to

be shrimp in the evening or not. This

is a very complex behaviour and is

only possible because they have a

sophisticated brain,” said Pauline

Billard, who took part in the research.

When cuttlefish hatch out, they

already have a large central nervous

system and are able to learn from

a young age. They are capable of

responding to their environment

in a flexible fashion, and can adapt

their hunting, mating and behaviour

strategies to ensure the best possible

outcomes. In this study, they proved

that they could adjust

their foraging behaviour

on a day to day basis

to guarantee that they

were eating enough, but

also not missing out on

their favourite foods.

In evolutionary

terms, cephalopods

split from the vertebrate

lineage around 550

million years ago, yet

their nervous systems

are remarkably similar.

These findings could

offer new insight

into when complex

cognitive ability

evolved.

Cuttlefish

will skimp on

lunch if they

know their

favourite

meal, shrimp,

is for dinner

It’scommonly believed that one-third of all

food is thrown away, but this “grossly

underestimates the extent of food wasted,”

according to researchers in the Netherlands.

They found food wastage to be rising

rapidly from those with a daily spend of

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

first estimated in 2005 by the Food and

Agriculture Organization of the United

Nations (FAO), who found food waste to be

214 calories per person, per day. However,

this didn’t account for differences in income

and buying habits. The new study estimates

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

UP TO TWO-THIRDS OF ALL FOOD MAY BE WASTED AND THE RICH ARE

THE WORST OFFENDERS