Sentience in Farm Animals: Aquatic Animals Lobsters and Crabs

Lobsters may live for well over one hundred years.

The largest kind of crustacean, the giant spider crab of Japan, measures up to 12 feet across between its outstretched claws.

Even more so than fish, Crustaceans are less likely to be considered as sentient or in other words aware and conscious of the world around them. However, it should be obvious that any creature with sensory organs has at least this quality of consciousness.

Crustaceans have exoskeletal sense organs which include hairs sensitive to sound, touch, odour, taste, humidity or temperature, and often two compound eyes and one or more simple eyes. Lobsters have compound eyes, as do most arthropods, but these are stalked to provide a broader field of view. Like nearly all multicellular animals crustaceans have a central nervous system consisting of a brain, a ventral nerve cord and ganglia, more about this later.

For an interesting explanation about the sensory capacity of crustaceans read the article Inside the brain of a crayfish from Biology news. net

Crustaceans are invertebrates (animals without a backbone) consisting of a vast number of species numbering approximately 42,000. Crustaceans include crabs, lobsters, crayfish, barnacles, shrimps, snails, and woodlice to name just a few. Most humans treat invertebrates as though they are creatures without feelings either physical, such as an ability to feel pain, or emotional. I think one of the greatest stumbling blocks most people have in assigning sentience to these creatures is the considerable difference between them and ourselves. Attributing consciousness to crustaceans for many people it would seem is even more difficult than considering the possibility of sentience in fish, the least considered of all vertebrates (animals with a back bone) to be sentient.

For now I will consider the sentience of Aquatic crustaceans, three of the most familiar: lobsters, crayfish and crabs. It is my opinion that without a doubt all complex animals are sentient and crustaceans are no exception, such to my mind is common sense. But what evidence other than common sense will convince a sceptic that these creatures have a conscious awareness of themselves, other creatures and their environment and that these animals can think and feel, even experience emotions both negative and positive?

Lets look at some of the characteristics and behaviours of crustaceans that indicate sentience.

Firstly the most fundamental and most obvious: An ability to feel pain

As with any creature the most basic indication of sentience is the animal's ability to feel pain. A creature has to be aware to experience pain and suffering, therefore if it can be demonstrated that an animal feels pain we must accept that the animal is on some level a sentient being. Having said that though an inability to experience pain as we perceive pain would not indicate the absence of sentience merely the absence of this aspect of sentience. Remember that sentience, conscious awareness, varies in both kind and degree from one species to another or even within the same species. Humans are sentient on different levels and to different degrees, for a more detailed discussion on sentience please refer to Sentience in Farm Animals. It has never occurred to me that crustaceans, or any other creatures, do not feel pain, to my mind this is obvious, pain is a vital survival mechanism.

What is the evidence that these creatures feel pain? It has to be considered that the issue regarding pain is an important one not merely to prove sentience but as a consideration against the inhumane treatment of these animals, the most hideously cruel of which is cooking them alive! Caught lobsters and crabs after being kept alive for long periods of time are submerged in water and boiled alive. Crayfish and shrimps are also treated likewise.

Anyone having heard the scream of a lobster as he is boiled alive, and the frantic scrapping of his claws along the side of the cooking pot as he desperately tries to escape the increasing searing heat of the water, cannot surely doubt the poor creatures experiences pain. In his book Animal Liberation Peter Singer suggests two criteria which should be considered when attempting to ascertain if any animal is capable of suffering:

"...the behaviour of the being, whether it writhes, utters cries, attempts to escape from the source of pain, and so on; and the similarity of the nervous system of the being to our own."

Crustaceans fulfil this criteria, even though the nervous system of crustaceans is simpler than our own.

I think that most of our attitudes towards such creatures as always arises from our misconceptions regarding the anatomical structure of these animals. For instance many people are not aware that decapod crustaceans which includes lobsters, crabs, hermit crabs, shrimps and crayfish have a complex nervous system consisting of concentrations of nerve cells connected by a nerve cord and a brain. Although the system is somewhat different than our own, the nervous system of crustaceans allows them to not only experience pain and suffering but in addition makes them very much aware of their environment. The following is a short extract again from Animal Liberation by Peter Singer wherein he comments upon the ability of crustacea to experience pain, he includes the observations of Dr John Baker a zoologist at Oxford university concerning the evidence that crustaceans have the capacity to experience pain and suffering :

"Crustacea - lobster, crabs, prawns, shrimps - have nervous systems very different from our own. Nevertheless, Dr John Baker a zoologist at the University of Oxford and a fellow of the royal Society, has stated that their sensory organs are highly developed, their nervous systems complex, their nerve cells very similar to our own, and their responses to certain stimuli immediate and vigorous. Dr Baker therefore believes that, lobster, for example, can feel pain. He is also clear that the standard method of killing lobster-dropping them into boiling water-can cause pain for as long as two minutes."

Crustaceans like vertebrates - animals with backbones which includes mammals, birds, fish, and reptiles - produce opioid peptides, which modify nervous transmission of pain. Opioids are substances that mimic the effects of opium in the brain, in other words they are nature's natural painkillers. We have all heard in recent years about endorphins - opioid polypeptide compounds produced by the pituitary gland and the hypothalamus in vertebrates - which are released to modify pain in humans and other mammals, and which have an analgesic effect; they bring about relief from pain. Lobsters and crabs produce opioids. Furthermore crustaceans respond to morphine in exactly the same way as mammals. Consider that it these creatures did not feel pain why would their bodies produce opioids? There has not been found an alternative function for opioids other than pain relief.

You can read about this and other evidence that crustaceans and cephalopods feel pain In a review released in 2005 by the Scottish animal rights group Advocates for Animals which has compiled a report that scientific evidence supports the idea that crustaceans experience pain and suffering, below are two extracts:

"The Likelihood that decapod crustaceans can feel pain is supported by the fact that they have been shown to have opioid receptors and to respond to opioid (analgesics such as morphine) in a similar way to vertebrates. For example, morphine is found to reduce a crab's reaction to an electric shock or being presented with a pseudo-'predator'. Natural opiates are found in crustaceans as they are in vertebrates. These finding strongly suggest that opioids have a role in mediating pain in crustaceans in the same way as is known to occur in vertebrates. A recent study 'Opinion of the Scientific Panel for Food Safety of the Norwegian Food Safety Authority' commented that opioid in some invertebrate species might be involved in pain perception and relief in much that same manner as in vertebrate species."

Furthermore studies have shown that decapod crustaceans are able to remember painful stimuli, objects or situations which have caused them pain, and thereafter they, just like us, try to avoid them. The same study has conclusively shown that crustacean are able to learn, make discriminations, have the ability to remember and understand places and other individuals and form hierarchies and suffer psychological stress. After capture they make considerable effort to escape, and also suffer.

In addition, the behaviour of decapod crustaceans shows that they can recognise and remember painful or threatening objects or situations and try to avoid them. The animals also have the ability to learn and to make discriminations. They show some understanding and memory both of places and of other individuals, for example by forming social hierarchies when a number of animals are kept confined together.
When crabs and lobsters are caught, taken out of the water and handled, they make vigorous efforts to escape. Physiological studies of lobsters show that they are very stressed by the process of catching, handling, transport and being kept out of water. Many crabs and lobsters arrive at factories very weak, dying or dead. Lobsters make vigorous attempts to escape when they are put alive into boiling water to be cooked. They also often shed limbs, an escape response known as autotmmy, which is likely to be a response to pain.

To sum up

Lets look again at the indicators of sentience which has been demonstrated exist in crustaceans : An ability to to learn, to experience pain and suffering, to retain the memory of painful stimuli, other individuals and to form social hierarchies and recognise when they are in danger.

It is highly recommended than you read the full report: http://www.advocatesforanimals.org/images/documents/Cephalopods%20and%20Decapo.

It is interesting to perhaps note that scientists do not fully understand pain in humans. Pain is experienced when an electrical signal is sent to your brain from nerve endings, at which time the brain releases the natural opiate like painkillers mentioned earlier called endorphins and generates both a psychical and emotional response. However the details remain unclear which is why there are many people who suffer pain seemingly without an obvious cause, such as injury or disease, and who suffer with no relief. I myself suffer with chronic aches and pains for which there is no physical cause and pain killers are ineffective. We often hear of people with anxiety disorders or depression being diagnosed with a somatisation disorder, such people do not imagine that they are in pain, despite the lack of physiological evidence they genuinely experience real pain, some even become unable to walk. We might assume that pain or the degree of pain is therefore not entirely dependent upon the pocession of a complex nervous system and consequently pain may be experienced even in simple nervous systems. It would be wrong to simply assume that the less complex a creature's nervous system the less severe the pain or even to assume that the animal experiences no pain at all.

Research at Queens University Belfast in 2007 by animal behavioural expert Robert Elwood has demonstrated that crabs feel pain and furthermore they remember it and thereafter avoid the source of pain. Hermit crabs have no shell of their own and occupy other suitable structures, shells abandoned by other creatures for instance. In an experiment small shocks where administered to the abdomen of some of the hermit crabs. Only those crabs who received the shock left their shells. This indicates they experienced the sensation as painful:

"As part of the research, wires were attached to shells to deliver small shocks to the abdomen of some of the crabs.

The study revealed the only crabs to get out of their shells were those which had received shocks, indicating that the experience was unpleasant for them. Hermit crabs are known to prefer some species of shells to others and it was found that they were more likely to come out of the shells they least preferred.

The main aim of the experiment was to deliver a shock just under the threshold that causes crabs to move out of the shell, to see what happened when a new shell was then offered.

Those responsible for the study said crabs that had been shocked but remained in their shell appeared to remember the experience of the shock.

Professor Elwood, who previously carried out a study showing that prawns endure pain, said: "There has been a long debate about whether crustaceans including crabs, prawns and lobsters feel pain.

"We know from previous research that they can detect harmful stimuli and withdraw from the source of the stimuli but that could be a simple reflex without the inner 'feeling' of unpleasantness that we associate with pain.

"This research demonstrates that it is not a simple reflex but that crabs trade-off their need for a quality shell with the need to avoid the harmful stimulus."

To fully understand the implications of this study please read the entire article concerning this important research, which clearly demonstrates that these animals experience pain.

BBC NEWS | UK | Northern Ireland | Crabs 'sense and remember pain'

Also research was carried out at Queens on 144 prawns. In this experiment the antennae of the prawns was rubbed with sodium hydroxide or acetic acid (vinegar), after which the animals began to increasingly groom the afflicted area and rubbing it against the side of the tank. Prof Elwood says "The prolonged, specifically directed rubbing and grooming is consistent with an interpretation of pain experience," This focused reaction is similar to that seen in mammals exposed to a noxious stimulant. After local anaesthetic was administered this behaviour was mitigated. However the controls who did not receive the anaesthetic did not show reduced behaviour. Professor Robert Elwood, who headed the study, argues that sensing pain is crucial to a prawn's survival, because it encourages them to avoid damaging behaviours. He further expresses the idea that even the lowliest of creatures need to experience pain to avoid harmful experiences and to increase their chances of survival, and that similar sensitivity to pain is experienced by lobsters, crabs and other crustaceans.

More information : Prawns and lobsters 'do feel pain' - Channel 4 News

This research published in the journal Animal Behaviour highlights the need to consider how crustaceans are used in the food industry. Professor Elwood is concerned that a potentially large problem is being ignored.

I have to state here though that I don't condone such experiments which result in any creature being subjected to pain and only make reference here to this and similar research as such is in the interest of these animals as this research shows that the response to pain was the same as that observed in mammals. I, like many others consider that such experiments are not necessary as it is obvious that these animals feel pain, and even if it cannot be proved it is best to err on the side of caution and to consider that an animal feels pain until it can be proven otherwise.

The following is a more down to earth observation. Below is an interesting comment from Janet Richetti a contributor to responses to a PETA Files blog entry:

Yes, Crabs feel pain.

"I was driving in Florida one day and a huge land crab walked out on the road, I thought it was a tree branch, as it was windy, I hit it and removed it's claw and it screamed in pain, rocking back and forth; I was banging on doors so someone can help me and a gentleman working in the yard came out to the street and killed the crab; as he agreed this poor crab was in excruciating pain."
The PETA Files: Crabs Sense and Remember Pain. Duh.

Pain however is not the only indicator that crustaceans are sentient.
Here is a fascinating article from Scientific American concerning the method fiddler crabs use to find their way home by an ingenious process known as Path Integration, the name given to the method thought to be used by animals for dead reckoning the process of estimating one's current position based upon a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course.

Charles Darwin and J.J. Murphy first postulated an inertially-based navigation system in animals in 1873. Studies beginning in the middle of the 20th century confirmed that animals could return directly to a starting point, such as a nest, in the absence of vision and having taken a circuitous outwards journey.

Extract: Path integration: Path integration - Wikipedia, the free encyclopedia

Extract: How Crabs Find Their Way Home
Fiddler crabs track strides to help them find their burrows
By Adam Marcus

Studies conducted by John Layne, a biologist at the University of Cincinnati.

A new study has found the first direct evidence that fiddler crabs monitor their travels by tracking their strides.

To Layne, the results, set to be published next month in Current Biology, indicate that fiddler crabs perform sophisticated math whenever they leave home. "We think they're summing steps," he says. They know how many strides they've taken and the length of each, and that magic number gives them their distance from home.

The next step, says Layne, is to determine what, exactly, crabs are doing when they sum their strides. One possibility is that sensors called proprioceptors in the animals' legs somehow tally both the number and length of their strides. Other options, he says, are that the brain itself is counting its outgoing commands to move the legs or even that the crabs can measure their own energy expenditure over distance.

Please read the entire article :

How Crabs Find Their Way Home: Scientific American

These creatures appear very smart do they not, to suggest that such behaviours are automated, wired into the creatures' brains seems very far fetched. Surely there is some measure of cognitive thinking involved here which requires intelligence, sentience or in other words awareness. There may well be some intelligent thought behind such complex calculations.

..nature may find it more efficient to endow life-forms with a bit of awareness rather than attempting to hardwire every animal for every conceivable eventuality.
Dr Donald Griffin

Dr Donald Griffin was the founder of the modern field of cognitive ethnology, he considered that it was unlikely that humans where the only thinking being on the planet.

Jonathon Balcombe in Pleasurable Kingdoms postulating the possibility that insects, creatures few consider as conscious, are sentient rather than mindless automatons. In this extract he comments upon the ideas of Dr Donald Griffin :

As Dr Griffin argued , we should not too hastily dismiss insects as unconscious merely becasue they are small and only distantly related to us. Having awareness and behaving flexibly confers great advantages over being a mechanical stimulus responder. The latter can be harmful in a complex world. An automaton insect whose system inflexibly recognised water as a ‘flat shiny surface’ might find itself licking an oil slick. Finding and getting water requires fewer cognitive steps for an aware animal than a blank one, whose system would presumably require a continuous series of yes/no loops: turn right, turn left, straight ahead, identify flat surface, land extend tongue, lap and so on.

The evolutionary survival benefit of a sentient creature over of that of an automaton would be the more advantageous for any creature including crustacean which rather like insects few equate with sentience. It would be incredulous surely for such a complex brain to have evolved that could respond automatically to an infinite number of nuances in any and every situation!

Crustaceans are no more reflex automatons than are insects, fish, birds or mammals including ourselves, they experience pain and the suffering which arises from pain. Furthermore I personally consider they are able to think and experience emotion including fear. Without experiencing pain and remembering the experience and consequently avoiding the source of pain they like all creatures would not survive long. Equally with out experiencing fear, a reminder of the possibility of harm, their continued existence would be limited.

In fact Invertebrates have played an important role in discoveries about how the nervous system works.

In my opinion all creatures with any kind of nervous system are sentient. All multicellular animals, with the exception of sponges, have a nervous system even a simple one such as that found in jelly fish; a jelly fish does not have a central nervous system but has instead a loose network of nerves through which he is able to detect stimuli, for instance the touch of another animal. Even though Sponges do not have nerves or sensory cells, they will nonetheless respond to touch or pressure to the outside of the sponge, which will then cause a local contraction of the animal's body. However the sponge is a more complex animal than has been previously realised as research has discovered that sponges carry the beginnings of a nervous system.

The possible origins of the nervous system have been found in the simple sponge, an animal with no nervous system of its own. Sponges carry the genetic components of synapses, which may have been co-opted by evolution as a starting point for proper nerve cells

Sponges are the most primitive of all animals. They are immobile, and live by filtering detritus from the water. They have no brains or, for that matter, any organs, tissues or nervous system of any sort. If you were looking for the evolutionary origins of animal intelligence, you couldn’t really pick a less likely subject to study.

So it was with great surprise that Onur Sakarya from the University of California, Santa Barbara found that sponges carry the beginnings of a nervous system.

With no neurons to speak of, these animals still have the genetic components of synapses, one of the most crucial parts of the nervous system. And their versions share startling similarities with those of humans.

Please read the rest of this fascinating article :

Simple sponges provide clues to origin of nervous system « Not Exactly Rocket

Even in the case of those creatures who do not have a nervous system I think it is important to not rule out the possibility of sentience nonetheless. I personally would not buy a natural sponge.

Is a brain a requirement for sentience? Can a animal be sentient without a brain or nervous system?

How about microbial intelligence?

Bacteria may not have brains, but they are intelligent. Lynn Margulis,

Lynn Margulis and Dorion Sagan are the authors of Microcosmos: Four Billion Years of Microbial Evolution, which was first published twenty years ago.

Access the link below to read the fourth part of an interview conducted by Astrobiology Magazine with Lyn Margulis where she discusses the evidence for bacterial intelligence. Albeit controversial this is a fascinating article where the possibility is considered that a brain is not necessarily a prerequisite for intelligence.

Below is an extract from the aforementioned interview

Astrobiology Magazine: In Microcosmos, you talk about bacterial intelligence. A lot of people have trouble with that concept because -

Lynn Margulis: - Well, they haven't been to parties with adolescents -

AM: - they tend to think intelligence comes from brains.

LM: I know they do. They're wrong.

AM: Can you explain how you view bacteria as being intelligent?

LM: If you look up consciousness in the dictionary, it says, "awareness of the world around you," and that's because you lose it somehow when you become unconscious, right? Well, you can show that microorganisms, or bacteria, are certainly conscious. They will orient themselves, they will work together to make structures. They'll do a lot of things. This ability to respond specifically to the environment and to act creatively, in the sense that that precise action has never been taken before, is a property of life. Of course, it has to be moving life, or you can't tell. You can't tell if a plant is thinking, but in organisms that move, you can tell their intelligence.

For example, take Foraminifera - they're single-celled sea creatures, protoctists. The Egyptian pyramids are built of their shells. A colleague of mine put one of these forams in a dish with a small crustacean animal, like a water flea. He was going to watch the crustacean eat the foram. The foram's a single cell, and smaller, right? And he saw the foram kill, trap, and completely destroy and eat the animal. He's got beautiful movies of it. So that group of organisms not only can eat animals, but they can make hunting towers, and they can hunt from the top of the towers.

Please read the rest of this interesting article:

Bacterial Intelligence :: Astrobiology Magazine - earth science - evolution

Sentience is a difficult concept to grasp, what makes you, you, makes you aware of your environment, why you think the way you do; who is it that looks out of your eyes? Some would respond that it is our brain that makes us aware. And yes indeed our brains and also our genes play a considerable role in who we are and how we perceive the world. But Is all you are the sum total of your brain, how you brain is wired so to speak? Is who you are entirely determined by genetic coding, much like a computer program's functions and actions are determined by HTML codes. I doubt there are many who think that who we are is determined by the circuitry of our brains. Although faulty wiring (neurological dysfunction) may be responsible for mental illness, often behind the seeming involuntary confusion of mental illness there is often a person who recognises that there is something amiss deep down underneath all the neurosis or even psychosis. Is this the real you. Yes of course a good portion of our behaviours and bodily functions are determined by our brain, our nervous system and by our five senses. But we know, do we not, that there is more to us than our brain and nervous system.

Emotion is another indication of sentience, similar to fish it is more difficult to determine if crustaceans have emotion as thy like fish lack expression. However like fish we should not assume that becasue these animals lack expression that these creatures feel no emotion. Crustaceans have been observed to show great tenderness and to by playful. More about this later.

In the case of creatures such as crustaceans and insects many people assume they lack sentience because these creatures appear so unaware of our existence. Rather an arrogant assumption to make, after all we are also not obviously aware of other animals, such as dust mites for example, it is only with the invention of the microscope that we know of the existence of the teeming millions of creatures that inhabit our world previously invisible to the naked eye. Moreover there are many humans who seem oblivious to the rest of us, at least for the most part, for instance a person who is profoundly autistic may appear unaware of the presence of other people, and will not associate or respond even to his or her parents. In fact it is this facet of autism that is the most distressing aspect of the condition for parents. The person however is sentient and often extremely intelligent, he may not seem this way as his attention is focused elsewhere and he presents as oblivious to your existence failing to interact in the way we perceive as normal.

Below is a description of Autism
Autism Brief
Autism is defined by three features existing in a child's or an adults behaviour one of which the avoidance of reciprocal interactions.

A strong tendency to avoid social contact, especially to avoid reciprocal interactions, such that the child is said to be aloof, withdrawn and living in a world of his/her own. When an infant or toddler has a strong tendency to avoid social contact, especially to avoid reciprocal interactions, (a persistent failure to develop two-way social relationships in any situation) such as s/he does not cuddle, make eye contact or respond to affection and touching, that the child is said to be aloof, withdrawn, and living in a world of his/her own, parents are seriously concerned.

Many people believe that in many respects autism is simply another way of being. And likewise concerning such characteristics in animals - particularly in animals such as crustaceans who appear to neither express emotion in a way that we can perceive or interact with us in the same way as your cat or dog - we should consider likewise that sentience in these animals may be in many respects different from our own, another way of being, but sentient nonetheless.

To a lesser degree there are many people who for a variety of reasons often appear to live in a world of their own absorbed it seems by things in their environment unnoticed by others.

Such people are of course sentient despite their treating others as though they are non existent. Sentience is not expressed in the same way homogeneously in humans, it presents in a verity of ways in different types of people and in different types of animals. Therefore if any animal appears oblivious to our existence this does not mean that the creature is not sentient, we should be careful not to assess sentience in other creatures according to how it presents in the typical human. And furthermore animals are sentient on levels not available to us, for instance with what is often referred to as a sixth or heightened sense.

Concerning emotions lets look at some indications that emotion is present in crustaceans despite the lack of obvious expression

One of the indications of sentience at least as we perceive sentience is the ability to experience pleasure. Event though we should as already said not compare our sentience with that of other creatures if does help to establish sentience for those who persist in their belief that certain creatures lack this quality.

Pleasure is expressed in an ability to play, those of us with a cat or dog know that these animals enjoy play.

Admittedly there are few examples of play in crustaceans but this may simply be due to our lack of observation, after all we are not closely associated with these animals. It has though been observed that Fiddler crabs mischievously remove the lids off the burrows of other fiddler crabs.

Pleasure in animals is often found in touch
Below is another extract from Jonathan Balcombe's book 'Pleasurable Kingdoms,' Chapter 10 - From Flies to Fishes, where he discusses the capacity for pleasure experienced by invertebrates.

In the extract below he describes sensual touch in fiddler crabs and lobsters:

Touch is important for intimate relations in a diversity of invertebrates. Female crabs become increasingly receptive to a male's gentle touch. A Male fiddler crab clambers onto the back of the female he is courting and uses his large foreclaw to tap and stroke her carapace. The carapace may also be plucked in species which adorn themselves in seaweed or other materials. With his walking legs, he continuously strokes the female, on who the effect appears hypnotic, for after a few minutes she becomes motionless, In this state the female is flipped onto her back, from which position the two can mate, a process that lasts about one hour. Male lobsters also gently caress the females carapace as a prelude to mating. If flies, beetles and crabs require special types of tactile stimulation to get in the mood, we may not wish to assume that the phenomenon is devoid of feeling

Can we honestly say that such tenderness is the result of automatic behaviours, utterly instinctual or that behind this behaviour neither of these creatures are aware, that neither feel emotion, pleasure, satisfaction. Ask yourself: what would be the point of such tender caresses if these creatures derived no pleasure?

Below is an extract from In Lobster Courtship, Traits Like Humans
Cornelia Dean, New York Times

The female lobster initiates mating by seeking out the male lobster with the most luxurious home, which for her means the largest or most secure burrow, usually on a rocky patch of ocean bottom. She may hang around its entrance for days, enticing him with her intoxicating scent — pheromones in her urine, according to Jelle Atema, a biologist with the Boston University Marine Program, who studies lobsters in his laboratory at the Marine Biological Laboratory at Woods Hole, Mass.

Eventually, the smitten male admits her. Their foreplay is elaborate, beginning with a mock boxing match and ending with the male stroking the female — "tenderly," people who have seen it say. The female sheds her shell and as soon as she is strong enough to stand again the male turns her on her back and they mate, like missionaries, as Trevor Corson writes in his book, The Secret Life of Lobsters.

To finish reading this article:

In Lobster Courtship, Traits Like Humans: Cornelia Dean, New York Times

Intelligence is often an important criterion in accessing the presence of sentience. What evidence do we have that crustaceans are intelligent, in any event; does intelligence indicate sentience? I believe that an animal may be sentient without being intelligent, at least the kind of intelligence we understand from our own perception of what it means to be intelligent. Animals have their own kind of intelligence in accordance with the type of lives they live. It is possible to be sentient without having significant levels of intelligence but it is a good indicator that if an animal does posses some observable intelligence that demonstrates cognitive abilities then there is a good chance the animal is sentient. The example of how fiddler crabs navigate is to my mind an example of intelligence, but consider less complicated examples. For any animal to live thier lives requires the ability to find food and shelter and to defend itself and its young from predators. Look at this video of the shrimp and how he defends himself from an octopus attack, surely there is intelligent thinking here, the shrimp has to access the situation and take appropriate action to defend himself.

YouTube - Californian mantis shrimp (deep sea)

I cannot really envision any living creature as an automaton generically programmed rather like an organic computer without awareness.
The fact that crustaceans feel pain has been demonstrated, as is their ability to remember pain and avoid painful stimuli, whether they experience emotion, self awareness has yet to be scientifically proved through experimentation. Although considering the above observations I am left with little doubt that these creatures, in addition to experiencing pain and suffering, are aware of their environment, feel fear and experience emotion such as pleasure. However because such has yet to be proven to the satisfaction of science or because we may not be aware of the feeling of crustaceans does not mean they do not have them and until the time it can be proved otherwise we need to accept that there is a strong possibility these creature have awareness, are sentient.

There is no doubt that all creatures including crustaceans experience pain and if this is the only indication that an animal is sentient then that is enough to consider our behaviour towards the animal.

How can any civilised society allow a living feeling being to be boiled alive and be generally so badly mistreated?

Links

Internal:

Animal Rights Lobsters

External:

External links ill open into a new window

Lobster Liberation!

The PETA Files: Lobster Liberation . . . Literally

http://www.viva.org.uk/guides/endoftheline.htm

The PETA Files: Lobster Spends Century in Ocean to Become Seafood?

Lobster Liberation - Scientific Review Proves That Lobsters Feel Pain

Global Action Network: Animals: Lobsters

Put an end to the boiling of lobsters and other crustaceans - Petition - Sign

Credit

Banner photograph by by flick user LightIsBeauty Florida Blue Crab on Flickr - Photo Sharing! licensed under Creative Commons — Attribution-Noncommercial 2.0 Generic