Page 29 - BBC Wildlife - August 2017 UK

talking

MINDING

NEMO

Fish have complex inner lives – and yes, they feel pain. So let’s
treat them with more respect, says Jonathan Balcombe.

ow do you stress a primitive and dim-witted. Having spent five
surgeonfish? One way is to years watching fishes, compiling observations
abduct her from her home from others and, most importantly, delving
and place her in a shallow into a substantial and expanding scientific
bucket of water for half an literature, I’ve come to view fishes as complex
hour. That’s what a research beings with inner lives – even in some cases
H team from the University Machiavellian ones.
of Lisbon did a few years ago with 16 of
32 striated surgeonfishes caught on the erhaps our fishy prejudices stem
Great Barrier Reef. This treatment had the from our expectations that fishes
intended effect of raising blood cortisol, a must show expressions that we
standard measure of stress. associate with having feelings. “Fish
Then each stressed fish (and some P are always in another element, silent
less stressed controls) were individually and unsmiling, legless and dead-eyed,” writes
placed for an hour in a separate tank with Jonathan Safran Foer in his 2009 bestseller
Fish have feelings: striated surgeonfish are
a handmade model painted to closely less stressed when cleaner wrasse are nearby. Eating Animals. In those flat, glassy eyes we
resemble a cleaner wrasse. Cleaner wrasses struggle to see anything more than a vacant
provide parasite removal services to the stressed (and less stressed) surgeonfishes stare. We hear no screams and see no tears
surgeonfishes and other ‘client’ species on were drawn to the mobile model like children when their mouths are impaled and their
reefs. They also sometimes pause to caress to chocolate. They swam over to the model bodies pulled from the water.
some clients with their pectoral fins, a and leaned their bodies against it to receive Those unblinking eyes – constantly
gratuitous gesture thought to enhance the strokes an average 15 times during a session. bathed in water and thus in no need of
cleaner’s reputation with favoured clients. By contrast, if the cleanerfish model was lids – amplify the prejudice that fishes feel
nothing. The myriad sounds they produce
stationary, it was ignored: zero visits. Cortisol
When the model wrasse was mechanically
; wrasse: WaterFrame/Alamy rigged to move in a gentle sweeping motion, levels dropped markedly in the stroked fishes, underwater, for instance by vibrating their
and dropped in proportion to the time spent
swim bladders or grinding teeth or bones
together, are mostly ineffective in air, and
in contact with the undulating models. (I am
happy to report that all 32 surgeonfishes were
so we are deaf to them. With a deficit of
ustrat on by Jam e W gna “THIS EXPERIMENT SHOWS show that fishes may feel upset. It also shows we are numbed to the fishes’ plight.
stimuli that normally trigger our sympathy,
returned to their reef homes after the study.)
This remarkable experiment doesn’t just
THAT, GIVEN THE CHANCE,
Thanks in part to advances in diving and
that, given the opportunity, they will actively
underwater filming technologies, today we
FISH SEEK RELIEF FROM
know far more about fishes than we did a
seek relief via the pleasure of a massage. Such
century ago. Of at least 33,000 fish species so
capacities do not mesh well with the general
I UPSET VIA A MASSAGE.”
29
BBC Wildlife
August 2017 impression most humans have of fishes as far described, only a few hundred have been