Farm Animals main introduction
Sentience in crustaceans
Fish are more
intelligent than they appear. In many areas, such as
memory, their cognitive powers match or exceed those of
‘higher’ vertebrates including non-human primates
Brown University of Edinburgh
Fish are intelligent animals who lead complex
lives that rival those of your dog and other mammals.
Dolphins and whales are
accepted without doubt as intelligent creatures,
sensitive, aware, conscious: sentient. But what about other
aquatic creatures, the myriad
species of fish, 27000 in all, which is more than all
vertebrate species combined, are they sentient?
Approximately three new species of fish are discovered
each week! And even more vast are the huge
numbers of species of invertebrate creatures such as
molluscs - Octopuses, squids, snails, slugs, do they
posses sentience? The ocean is a vast habitat teeming
with life, astronomical in
number and diversity, creatures dwell even in the most
inhospitable of environments.
Here I will focus my
attention on fish and Crustaceans particularly lobsters
and crabs as it is these creatures
who are mostly exploited as food, however in the catching of fish
and lobsters many other aquatic animals suffer and die
as a consequence and you can read why by clicking here:
Aquatic Animals. The reason that this article will
only focus on fish, lobsters and crabs however does not
imply that other aquatic creatures lack sentience, in my
opinion most animals are sentient, and in time I will
add information as it becomes available concerning the
sentience of other aquatic animals, but for now most of
the readily accessibly information is limited and would
require more research by me and will take time.
To begin with lets discuss
fish. What are the indicators that fish are sentient.
It is often considered that fish are primitive life forms, however as the
oldest vertebrate group of animals they have been
evolving for 400 million years, they have had time to
evolve complex and diverse behaviours. Because of
their amazing diversity fish are said to be the most
successful of all vertebrates.
One good indicator of
sentience is a creature's ability to express emotion, but
how is emotion expressed in fish? How do we know that a
fish feels distress or fear, how do we know if he feels
pain or joy or experiences pleasure? Another good
indicator of sentience is intelligence, are fish intelligent? Many
people think not, but research is proving otherwise.
Pain is the most basic
indicator of sentience, but do fish experience pain? The
excuse of anglers when catching fish with hooks that
pierce thier mouths is that this area is numb and they do not feel pain. As you
will see later on this is one of the most erroneous
misconceptions of all the incorrect ideas many people
have concerning fish, it is as unfounded as the notion that cows keep
Of all animals exploited
for food, fish
are thought to be the least sentient and sadly this is
due to a number of misconceptions, most notably that
lack of facial expression equals lack of feeling and
conscious awareness, in other words sentience, and are consequently not capable of feeling
pain or emotion. This is an incorrect assumption. Consider dolphins and Whales who similarly lack expression, at
least in comparison with how we show feelings, yet few
would deny that dolphins or whales are sentient,
intelligent and that they feel pain.
In her article 'What Fish Feel' researcher Stephanie Yue
of the University of Guelph in Canada explains the
findings of her team and discusses the ethical
implications. The following are extracts concerning the
findings of research into the sentience of fish, which among other points of
relevance demonstrates that rainbow trout not only have
the ability to learn but also to recall what they have
Expressing her concern about the increase in the
consumption of fish and the use of them in medical
research, Ms.Yue considers that the problem is that most people
experience an emotional distance from fish and
consequently do not consider them as sentient, as
creatures who feel pain or experience emotion. She says;
This may be because our present knowledge of
assessing suffering in fish is inadequate— in part
because fish do not typically display traditional and
obvious signs we are familiar with in other animals.
They are not capable of facial expression, nor can most
species of fish vocalize; given their general anatomical
structure, changes in body posture are extremely
However, recent anatomical, physiological,
neuropharmacological and behavioral studies suggest fish
can suffer in ways similar to "higher" vertebrate
From our studies on highly domesticated rainbow trout,
we have seen these fish show behavior that is much more
flexible and complex than was previously acknowledged.
We have found that trout have some cognitive capacity
that rivals that of mammalian laboratory animals, like
rats. They not only show the ability to learn, but they
also have memory of the things they learned—so they can
anticipate events and adjust their behavior accordingly.
This means some of their behavioral repertoire is
"purposeful" and lends evidence toward "conscious"
Please read the complete article
What Fish Feel
In addition to the above there is and has been
considerable research into the sentience and
intelligence of fish.
The fact is
fish are conscious creatures, they are sentient, research
demonstrates that they are far from the
automatons we have been led to believe.
Lets start with the most popular criterion which many
people adhere to as indicative of sentience:
intelligence. As before it is important to bear in mind
that intelligence or lack thereof does not imply a lack
of sentience, but if we can demonstrate that a creature
is intelligent it does go a long way towards
establishing sentience. But we should perhaps bear in
mind that animal intelligence is not comparable to our
own, even though when the presence of intelligence is
researched in animals it does seem as though we try to
prove animals have similar intelligence rather than
demonstrate that animals have perhaps a different kind
of intelligence. A degree of intelligence of some type
does of course demonstrate sentience, but is nonetheless
not a prerequisite.
A number of research projects have demonstrated that
despite having small brains fish have cognitive
abilities in advance of some mammals. These studies also
reveal that fish are fast learners, they can retain what
they have learned and they can make mental maps. The following is
an extract from The Telegraph concerning research into
the intelligence of fish:
"Tests on fish in aquaria at Oxford University have
shown that despite their tiny brains, they possess
cognitive abilities outstripping those of some small
Dr Theresa Burt de Perera made the discovery using blind
Mexican cave fish, which rely on subtle changes in
pressure to detect the presence of objects around them.
"In experiments, Dr Burt de
Perera found that the fish did more than merely avoid
bumping into objects in their tank. They built a
detailed map of their surroundings, memorising the
obstacles in them within a few hours. Once stored in
their brains, the fish used their "mental map" to spot
changes in the obstacles around them - a feat that
In one test, involving
obstacles arranged in a specific order, the fish proved
capable of memorising the order and quickly spotted when
Dr Burt de Perera swapped obstacles around."
To finish reading the article:
Fast-learning fish have memories that put their owners
to shame - Telegraph
Moreover concerning the amazing ability that fish have
to make mental maps, it has been shown that fish retain
this memory for about 40 days.
book Pleasurable Kingdoms Jonathan Balcombe describes
the incredible memory of the frillfin goby which lives
in rook tide-pools when the tide is high:
"If a rock pool
begins to dry up these fish leap to an adjacent pool.
Obviously, a missed leap might be fatal, and the
accuracy must be great in both terms of distance
and direction. How do frillfin gobies do this being as
they cannot see the adjacent pool? They memorise the
topography of the rocks during high tide. Captive fish
showed a marked improvement in orientation after an
overnight opportunity to swim over the pools during an
artificial high tide. Removing the gobies from
their home tide pools for various periods of time before
retesting their jumping ability showed that their memory
of familiar pools lasted about 40 days. Thanks to these
mental capacities, gobies caught in a shallow depression
avoid having to make a pure leap of faith."
Fish have the ability to learn by observing other fish:
"Did you know that fish can learn to avoid nets by
watching other fish in their group and that they can
recognize individual “shoal mates”? Some fish gather
information by eavesdropping on others, and some—such as
the South African fish who lay eggs on leaves so that
they can carry them to a safe place—even use tools."
Fish are communicate
with each other:
"Researchers from universities across America have
published research showing that some fish use sound to
communicate distress when nets are dipped into their
tanks or they are otherwise threatened. In a separate
study, researcher William Tavolga found that fish
grunted when they received an electric shock. In
addition, the fish began to grunt as soon as they saw
the electrode, clearly in anticipation of the torment
that Tavolga was inflicting on them.
Fish talk to
each other with squeaks, squeals, and other
low-frequency sounds that humans can hear only with
Some fish woo
potential partners by singing to them, but male sand
gobies, tiny fish who live along the European coast,
play “Mr. Mom,” building and guarding nests and fanning
the eggs with their fins to create a current of fresh,
Extracts from Fishing Hurts.com for
more information visit their website
The Hidden Lives Of Fish.
Even more amazing:
crimson spotted rainbow fish, which learnt to escape
from a net in their tank, remembered how they did it 11
months later. This is equivalent to a human recalling a
lesson learnt 40 years ago."
University of Edinburgh
Research shows fish can use
tools, they have log term memories of at least three or
four months and live in complex social structures.
‘Fish and Fisheries’ journal recently featured a
report on ‘Learning and Memory in Fish: Why fish are
smarter than you think’. The report, which contains
contributions from biologists around the world, claims
that fish are capable of pursuing Machiavellian
strategies of ‘manipulation, punishment and
reconciliation’; exhibiting stable ‘cultural’
traditions; and co-operating with each other to inspect
predators and catch food.
Fish not only recognise individual shoal mates, but also
monitor the social prestige of other fish and track the
relationships of other individuals. They also use tools,
build complex nests and can even exhibit impressive
long-term memories. Report co-author and edition editor
Dr Culum Brown, of the Institute of Cell, Animal and
Population Biology at the University of Edinburgh, said:
“Learning plays a pivotal role in the behavioural
development of all vertebrates, and fish are no
To finish reading this article from Hero. Hero is the
official gateway to universities, colleges and research
organisations in the UK
Multitasking? Yes indeed fish are very adept at this, an ability the eludes me.
"First came news
that fish feel pain, then research showed they’re
smarter than you might think …. now a new study shows
they’re good at multi-tasking too. University of
Edinburgh biologists have found that when fish are
vulnerable to attack, they become more adept at
concentrating on tasks simultaneously. Experiments with
a species of fish similar to guppies have shown that
fish from high-risk environments identified predators
with their left eyes and shoal mates with their right
eyes. The research is significant because it appears to
explain why humans have developed the ability to use
different sides of the brain for specific tasks. The
findings, which succeed earlier Edinburgh research on
fish pain and intelligence, are published online today
(21 July) in the Royal Society journal, Biology
"Dr Culum Brown,
of the University of Edinburgh’s Institute of
Evolutionary Biology, said: “Our study suggests that
lateralisation allows fish to concentrate on shoal mates
and predators simultaneously. Put another way, you could
say that fish are very good at multi-tasking. In fish,
all information received by the left eye is transmitted
to the right side of the brain, and vice versa.
Lateralisation is rather like having two computers to
process information in different parts of the brain
simultaneously, rather than just one."
To finish reading
News Article - School of Biological Sciences
Fish are individuals
perceive fish as all being the same both in appearance
and behaviour, creatures of habit, automatons with no
distinguishing characteristics. In my view this is yet
another inaccurate observation and one which scientists
are in the process of disproving as research validates
that fish are individuals with thier own personalities
and behaviours. Below is an extract from the Times
on-line article by Mark Henderson: Smart School of Fish
Expose Stupidity of a Popular Myth, which features a study
led by Lynne Sneddon of the University of Liverpool
conducting research into the intelligence of fish. The
finding of which not only demonstrate that fish are
smarter than we think but they have good memories and
are individuals .
trout certainly have contrasting personalities. Some are
bold and some are shy. The bold fish take risks, they
are quick to learn, more aggressive and active. Shy fish
are cautious and timid, and spend more time under cover.
“They also learn from their experiences: they adjust
their behaviour according to what they pick up from
In the study, which is published in the journal
Proceedings of the Royal Society, Dr Sneddon’s team
first watched rainbow trout as they were exposed to new
and unfamiliar stimuli in the form of shapes made of
Lego dropped into their tanks. Fish were then
categorised as bold or shy, depending on how quickly
they investigated the objects, and how closely they
To finish reading
the complete article:
Smart school of fish expose stupidity of a popular myth
- Times Online.
Fish have the capacity to feel pleasure.
Sentient beings are capable of experiencing pleasure.
Most people would not equate fish as creatures with the
ability to enjoy themselves and experience pleasure,
again another misconception. Here are some examples of
the ways that fish experience pleasure.
All animals like to be stroked, cat and dog owners know
the pleasure their animals derive from being stroked and
indeed the pleasure we derive from stroking them.
Fish it seems also enjoy the sensation of being stroked.
Contrary to popular belief fish are highly sensitive to
touch, equipped with sensory organs they can detect pressure changes in the water and minute electrical
Grooming by such creatures as cleaner shrimp and cleaner
fish is likely undertaken for the pleasure of the
tactile sensations involved in addition to the benefits
The use of cleaning stations, a place where fish and
other aquatic animals gather to be cleaned by fish of
several species and other creatures, is a widespread
phenomenon. The cleaner fish or other creatures nibble
parasites such as fish lice, fungal growth, loose skin
and other irritations from the skin.
Yes most certainly fish like to be touched, they have been observed to rub
against one another.
Fish even enjoy the sensations of touch by humans and
fish who are used to divers often allow themselves to be
stroked by them. There appears to be no advantage here, such as
food or other benefit, other than pleasure from the
Do fish seek out pleasure, do they play?
likely the answer is yes. Again in his book pleasurable
Balcombe writing about fish and their capacity for play
describes Zoologist E Meder observations of elephantine
fish in an aquarim :
"After witnessing surprising things going on in his
aquarium the Zoologist E Meder moved it to his desk so
that he could keep a closer eye on his lone elephantine
fish. One day to his astonishment, Meder watched the
fish balancing a small aquatic snail on his or her nose.
(Meder never determined or divulged the fishes' sex).
Small nylon balls added to the tank were treated
similarly. When these began to accumulate in the filter,
Meder suspended one on a string, and the fish would bat
balance and retrieve the ball. That this fish was kept
alone suggests that the play-like behaviour may have
been driven in part by boredom."
Surgeonfish in at a zoo in the USA were observed to gulp
in air at the surface of their tank, swim to the bottom
release the air and chase the bubbles to the surface.
There is admittedly not a lot of evidence that fish play
other than anecdotal, but there are numerous indications
that they do. Most of us have seen fish repeatedly leaping
out of the water, we may conjecturally imply that this
is some form of play as it serves no other perceivable
A curious creature is aware is he not, it is his
awareness, his consciousness that sparks his curiosity.
Curiosity is a sign that a creature is sentient. But
are fish curious? Fish are known to investigate unusual
objects in their environment. Children paddling in fresh
water often experience first hand the curiosity of
little fish who nibble at thier legs.
Capacity to feel pain?
Last but most certainly not
least: fish feel pain. As with all animals the most
basic indication of sentience is the ability to feel
pain and fish like all animals are capable of
Without sentience there can
be no pain, pain is felt, it is experienced by a
creature who is aware, the animal has to be aware,
conscious in order to feel the painful sensation and to
recognise it as painful and thereafter to avoid a
recurrence of the painful stimuli. So if we can
establish that fish feel pain we are well on the way to
validating the concept that fish are sentient.
Every creature feels pain,
without pain no creature would survive for very long,
pain is a basic survival mechanism. To my mind it is
common sense that fish like all animals feel pain. Fish have
the ability to feel pain just the way that your cat or
dog does or indeed you yourself.
literature is quite clear. Anatomically, physiologically
and biologically, the pain system in fish is virtually
the same as in birds and mammals."
Dr. Donald Broom
Fish have a nervous
system, this is a fact long known by neurobiologists;
they like us have a brain and nerves that sense pain in
much the same way as we do. The brains and nervous
systems of fish are very like our own. In fact fish have
endorphin like neurotransmitters, opiate like
painkillers, which act just as they do in humans and
other animals, and that is to relieve pain. This is their
only function, they are natures pain killers, they exist
in fish as they do in ourselves in order to relieve
pain. Scientists have mapped pain receptors all over
thier bodies including thier mouths, the obvious
conclusion is fish feel pain. Yes anglers, even in their
mouths, a hook in this sensitive area is rather like having your teeth drilled in exposed
areas without an anaesthetic!
Below is an article of which the angler should take
special note before catching a fish on a barbed hook.
Research challenges the myth among anglers that fish
can't feel pain from barbed hooks.
by Victoria Braithwaite
"Every year, sportsmen around the world drag millions of
fish to shore on barbed hooks. It's something people
have always done, and with little enough conscience.
Fish are … well, fish. They're not dogs, who yelp when
you accidentally step on their feet. Fish don't cry out
or look sad or respond in a particularly recognizable
way. So we feel free to treat them in a way that we
would not treat mammals or even birds.
But is there really any biological justification for
exempting fish from the standards nowadays accorded to
so-called higher animals? Do we really know whether fish
feel pain or whether they suffer — or whether, in fact,
our gut sense that they are dumb, unfeeling animals is
Determining whether any type of animal really suffers is
difficult. A good starting place might be to consider
how people feel pain. When a sharp object pierces the
human body, specialized nerve endings called nociceptors
alert us to the damage. Incredibly, no one ever seems to
have asked before whether fish have nociceptors around
their mouths. My colleagues and I in Edinburgh,
Scotland, recently looked in trout and found that they
do. If you look at thin sections of the trigeminal
nerve, the main nerve for the face for all vertebrates,
fish have the same two types of nociceptors that we do —
A-delta and C fibers. So they do have the necessary
sensory wiring to detect pain.
And the wiring works. We stimulated the nociceptors by
injecting diluted vinegar or bee venom just under the
skin of the trout. If you've ever felt the nip of
vinegar on an open cut or the sting of a bee, you will
recognize these feelings as painful. Well, fish find
these naturally irritating chemicals unpleasant too.
Their gills beat faster, and they rub the affected area
on the walls of their tank, lose interest in food and
have problems making decisions."
Finish reading the complete article
That Fish You Caught Was in Pain
This is an excellent article and raises important
ethical questions. In response though to the posed
consideration near the conclusion of this essay that:
could reasonably adopt a utilitarian cost-benefit
approach and argue that
the benefits of sport-fishing, both financial and
recreational, may outweigh the ethical costs of the
likely suffering of fish."
In my view there is nothing that can outweigh the cost
of suffering to another creature, most certainly not
financial or recreational, both of which are very minor
considerations. There are numerous out door pleasurable
pursuits which cause harm to no creature, for instance
bird watching and walking. There is nothing
more exhilarating than walking in natural surroundings
and observing nature and the great variety of life both
on land and in the water, surely to experience nature
and her creatures as live animate beings, must be a more
satisfying experience, rather than fishing - viewing the
demise of another living being after struggling
for his last gasp of air, in pain, on the
end of an anglers barbed hook!
"Really, it's kind of a moral
question. Is your angling more important than the pain
to the fish?"
Dr. Lynne Sneddon,
experience emotional distress in response to pain and
have been observed to engage in a rocking motion after
experiencing pain. This type of motion is very similar
to that seen in other animals including ourselves.
People with mental health conditions such as anxiety
disorders may rock backwards and forwards in response to
stress. Likewise people with autism rock backwards and
forwards a behaviour referred to as stimming, it is
thought that such behaviours are engaged in as a method
of relieving anxiety and stress. Fish, as we have
previously discussed, have good memories and can suffer
from the anticipation of pain.
informative information on the issue of the perception
of pain in fish from which some of the information in
the proceeding three paragraphs was obtained please
FishingHurts.com Fish Feel Pain
evidence read about recent research by scientists from
the Roslin Institute and the University of Edinburgh:
BBC NEWS | Science/Nature | Fish do feel pain,
Often cruelty to fish is
not considered due to the misconception that fish do not
feel pain, that they are not sentient, and most bizarre
of all, that they are not animals despite the fact that
most people have had at least basic biology taught to
them at school. Trying to change the way people think
about farmed land animals is difficult enough but when
it comes to fish the task is even more problematic. Fish
and other aquatic creatures need to be treated with the
same consideration as other sentient beings such as your
dog or cat or your budgie. Birds of course and in
particular poultry are often considered in the light of
Read more about the common
misconceptions concerning fish and the abuse that they
sufferer as the are dragged from their watery
Please note: I have included
aquatic animals in discussions of the welfare and
sentience of farm animals, although for the most part
with a few exceptions such as trout and salmon they are
not farmed in the literal sense, nonetheless they are
controlled and exploited for food therefore for ease of
expression I will refer to fish and other aquatic
creatures as farm animals.
Now please read about
sentience in crustaceans
Sentience in crustaceans
References and Links :
Animal Rights: Lobsters
Sentience in crustaceans
What Fish Feel
Fish Smarter Than Dogs?: Animal Sentience.com
That Fish You Caught Was in Pain
school of fish expose stupidity of a popular myth -
Fast-learning fish have memories that put their owners
to shame - Telegraph