New Scientist - USA (2020-11-07)

22 | New Scientist | 7 November 2020

Conservation

Space Marine biology

Suckerfish surf

across whales’ skin

Remora fish use a suction

disc on their heads to hitch

a ride on blue whales. By

attaching cameras to the

larger animal, researchers

found that the fish, also

known as suckerfish, can

detach themselves and

skim along the surface of

a whale’s skin in the rapidly

moving water produced

by the whale swimming

(Journal of Experimental

Biology, doi.org/fgdv).

Hawk-like drone

is an efficient flyer

A robot with wings can

glide like a hawk to fly

more efficiently. Motors

allow the robot’s wings

to fold in so that, when

travelling at optimum

speed, it uses 55 per cent

less power than would

be required with its

wings fully open (Science

Robotics, doi.org/fgdw).

Distracting gadgets

affect memory

People who report frequent

media multitasking – such

as texting while watching

TV or reading while listening

to music – perform worse

on memory tests than

those who don’t. Media

multitasking was also

associated with lapses

in attention (Nature,

doi.org/ghg7j9).

Biobank will house

corals to restore reefs

AN AUSTRALIAN conservation

team is compiling a living biobank

of coral species, in case we need to

rebuild the world’s reefs in future.

The Living Coral Biobank plans

to collect and house more than

800 species of the world’s hard

corals in a dedicated facility

in Port Douglas, Australia.

“We’re keeping this living

stock of corals alive should we

need to use them for restoration

and rehabilitation activities,”

WHEN the Philae lander arrived

on comet 67P/Churyumov-

Gerasimenko in 2014, it bounced

twice before reaching its final

resting place. The second bounce

exposed some very strange ice.

The European Space Agency’s

Philae lander was carried to comet

67P aboard the Rosetta orbiter.

When Philae was dropped to the

surface, the harpoons designed

to hold it in place didn’t fire, so

the lander bounced.

The location of the first bounce

and the lander’s final resting place

were both found. Now Laurence

O’Rourke and his colleagues in the

Rosetta team have located the

second bounce site by analysing

Rosetta’s pictures from before

and after Philae’s landing.

They found a bright streak across

a pair of boulders. “It was like a

chainsaw sliced through the ice,”

says O’Rourke. Philae appears

to have bounced between the

boulders, revealing the primitive

ice beneath the comet’s surface

dust (Nature, doi.org/fgjx).

Analysing the marks revealed

that the strength of the ice

was weaker than candyfloss.

“This ice that’s 4.5 billion years

old is as soft as the foam that’s

on top of your cappuccino,”

says O’Rourke. Leah Crane

says Dean Miller, director

of the project.

The Great Barrier Reef has

experienced three mass bleaching

events in the past five years,

and has lost more than half

of its coral colonies since 1995.

Starting on 6 November, the

team will collect living fragments,

tissue and DNA samples of corals

from the Great Barrier Reef. On

its first expedition, the team will

identify and gather specimens of

20 coral species – 5 per cent of the

Great Barrier Reef ’s 400 species.

The coral samples will be kept

in holding tanks in nearby city

Octopuses taste

food with their arms

OCTOPUSES can taste their prey

before eating it by using their

arms to “lick” it, which adds to

evidence that the appendages

are analogous to tongues with

“hands” and “brains”.

Octopus arms are lined with

suckers that include cells for

neural processing of touch and

taste signals. These allow them

to determine if an animal is good

to eat or is toxic, says Nicholas

Bellono at Harvard University.

That is useful because octopuses

tend to “blindly” hunt, sticking

their limbs into holes and

crevices to find hidden prey.

Bellono and his colleagues

found that some of the sucker cells

of California two-spot octopuses

(Octopus bimaculoides) respond

to touch and others to the

“taste” of chemicals in the water.

The suckers’ taste and touch

receptors reacted to water-soluble

chemicals, like bitter chloroquine,

as well as to chemicals that don’t

dissolve well in water, such as

those emitted by toxic prey,

says Bellono (Cell, doi.org/fgjz).

Octopuses do possess a

tongue-like organ in their

mouths called the radula,

but it doesn’t seem capable

of taste. The radula acts “more

like teeth”, says Bellono. CL-L

Cairns until a purpose-built facility

to house them is finished around

2025. Corals will also be stored in
      public and private aquariums
      around the world.
      Under favourable conditions,
      corals can live for thousands
      of years, says Miller. They can
      produce both sexually and
      asexually, and under asexual
      reproduction, they bud and
      produce clones of themselves.
      “We anticipate that the corals
      will double in size every six
      months, so effectively the biobank
      collection will double every six
      months,” says Miller. Donna Lu

Subsurface ice on comet 67P

is softer than candyfloss

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Really brief

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