Penguins have poor taste

Researchers sequencing the five different taste receptors in penguins were surprised to discover that the animals do not have genes that encode for receptors that are specific for savory meaty flavors (like fish!), sweet or bitter tastes. Instead, the data suggest that penguins are only able to taste the saltiness or sourness of their foods and also suggest that the birds may not be able to taste their fish dinner.

According to a quote from the lead study author Jianzhi George Zhang (University of Michigan, Ann Arbor), "As far as we know, penguins are the only birds that have lost three of the five basic tastes." He thinks that the protein Trpm5 is at the root of this problem because this protein does not work well at low temperatures. Incidentally, this protein is also important in the detection of the three lost types of tastes. Alternatively, it is possible that the tastes were lost because penguins usually swallow prey whole whereas salty tastes inform the animals of salt intake and sour tastes let them know if a food might be spoiled. "So it's likely that having sour and salty tastes is still beneficial to penguins," he says.

According to an article in New Scientist, cats and birds similarly lack receptors that can detect sweet tastes (with the exception of hummingbirds that have re-purposed other receptors to taste nectar). The most extreme loss has been found in dolphins and whales as they can only detect salty tastes.

I do not think that I would enjoy being a penguin. I cannot imagine life without tasting the bitterness of coffee or the sweetness of dessert...

Sources:

Current Biology, DOI: 10.1016/j.cub.2015.01.026

 New Scientist

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I find this extremely interesting I thought that Penguins genuinely liked that taste of fish

By Shannon Nicol (not verified) on 01 Mar 2015 #permalink

This is so interesting, I didnt know this, liofe must be so boring without the enjoyment of food.

I find this completely bizarre but possibly true. Penguins don't have a high range off hearing but they pick up on vibrations, their sense of sight and smell make up for what they miss with their low hearing range. They can also see very far distances and have a strong sense of smell, however it is known that they only have two taste genes- sour and salty, according to research conducted in China.

By Isabela de Cas… (not verified) on 11 Mar 2015 #permalink

This is quite interesting to see that a lot of marine mammals can only taste salt. It can't be at all nice to them as they already live in a salty environment . I think the salty water is probably what caused them to lose the other tastes over time.
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I find the concept about the Trpm5 protein confusing because penguins have an average body temperature of 39 degrees celcius,which is not a low temperature. I agree with Bosch,the salty water must be the primary reason they lost other tastes
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By Tumiso Monaiwa… (not verified) on 16 Mar 2015 #permalink

I am quite amazed that from these five types of taste: sweet, sour, salty, bitter and savoury; that these birds are only able to taste the sourness and salty combinations of their food.

By Tayla Rabie u1… (not verified) on 16 Mar 2015 #permalink

So will the same Trpm5 then work in South African penguins due do the higher temperature of the climate? u15034730

By Quinton R. (not verified) on 22 Mar 2015 #permalink

it is quiet fascinating that aquatic animals can only taste salt and sour flavours, this might be generally because they do not eat any sweet or bitter food thus loosing the receptors that are associated with those specific tastes the law of use and disuse ,the mammals will generally lose traits they do not use such as the receptors of sweet and bitter, but what baffles me is why is it that they cannot taste savoury flavours since that's their main foods.

By TIISETSO MAOKA… (not verified) on 22 Mar 2015 #permalink

I definitely don't fine this strange or surprising at all because their diet has never consisted of anything sweet or bitter so over time they have evolved to accommodate this.
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By Paige Derbyshire (not verified) on 27 Mar 2015 #permalink

I do not find this strange because the tongues in penguins are really small which indicates that they have only a few taste receptors. Taste obviously does not have a major impact on penguins. That is probably why they have lost there different senses of taste over time. 15120521

By Anthony Micklesfield (not verified) on 29 Mar 2015 #permalink

i think it is better not to have the taste receptors so when you run out of food you do not have to worry about what you eating exactly you just digest the food for the sake of filing up your stomach
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By tebogo(14169101) (not verified) on 30 Mar 2015 #permalink

I not only think that this information is interesting, I believe it could also be very useful. If penguins are unable to taste the fish provided to them in captivity, why not feed them something more nutritious? Because these birds are removed from their natural environment, I'm sure they also lack certain nutritious elements. I'm sure with this new information, scientists can develop special dietary supplements to keep our captive flightless birds extra healthy.
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By Cherise Swanepoel (not verified) on 30 Mar 2015 #permalink

What an interesting read. This does however make sense as proteins are made up of enzymes, and all enzymes have an optimum temperature at which they can function. Enzymes are highly sensitive to temperature changes and can be denatured when the temperature is not optimal. Would this change if they were to be placed in a different environment that will activate the protein Trpm5 ?

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By Kaycee Skinner (not verified) on 30 Mar 2015 #permalink

This makes sense because they live in a salty environment. The thing that doesn't make sense is the fact that they do not have low body temperatures, so why would they not have the Trpm5 protein? But why do they eat fish if they can't taste it because they don't have the gene that encode for receptors that specific for savory meaty flavors?
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By Liza van Rooyen (not verified) on 31 Mar 2015 #permalink

I find it interesting that birds do not have receptors that can detect sweet tastes as they tend to eat fruit. I also wonder why cats would lack receptors that detect sweet tastes but dogs seem to have these receptors as they are both domesticated animals. 15037780

By Olga Neveling (not verified) on 31 Mar 2015 #permalink

Could the reason the protein does not function in penguins not be because they have adapted to the environment and don't necessarily need the other receptors for sweet or bitter foods seeing as their staple diet consists of fish?

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By Thembekile Mkh… (not verified) on 31 Mar 2015 #permalink

If your diet only consists of salty or bitter food it can be imagined that over time you may loose the ability to taste sweet foods. Penguins should still be able to taste the salt and bitter because of course they have to recognise if their food is spoilt.

By AS Blecher (not verified) on 01 Apr 2015 #permalink

I think this is extremely interesting. Who would have guessed that they penguins has poor tastes. I would like to know. What if the food is rotting and is poisonous would the penguin pick it up while eating it ? Thank you for this amazing fact. 15076874

By EP Blignaut (not verified) on 02 Apr 2015 #permalink

Firstly, I'm thankful for my sense of taste. I think life would be rather boring if you couldn't experience all the flavours and tastes there is.
Nevertheless, the loss of certain tastes in penguins can also be because of the lack of taste buds. This is seen when their tongue is examined microscopically.

By R van der Walt… (not verified) on 02 Apr 2015 #permalink

Considering penguins swallow their food whole, why would their ability to taste salt and sour survive? Why don’t they have no perception of taste? Why would penguins need the perception of sour to recognise rotten foods if they have such a keen sense of smell to do so?

By Vormaurer, K.F… (not verified) on 03 Apr 2015 #permalink

I find this research to be very interesting. I also find it to be quite possible. Seeing that penguins are usually swallowing their food, which are fish, whole it raises the question whether the reason for the loss of taste is maybe not due to this habit of swallowing their food as there is then no need for any sense of taste?

By An-zelle Lubbe… (not verified) on 04 Apr 2015 #permalink

Scientist has discovered that penguins only taste sour and salty foods due to their genetics. The flightless bird has lost many of its taste receptors due to evolution. This evolutionary trait posses no harm to the penguin species as they swallow the fish whole and thus can still survive the evolutionary change that took place.
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By Jamie Mollentze (not verified) on 04 Apr 2015 #permalink

I find it so bizarre that sea animals have lost the ability to distinguish between different tastes. To mostly taste saltiness all the time does not sound nice at all. Like E. Bosch and many others suggest, I cannot help but wonder if the saltiness of the ocean they live in contributed to them not being able to taste anything else but salt... If penguins are exposed to a different food source, like fresh water fish instead of the salty ocean fish they are used to, would they be able to register the difference?

By Anita van Deve… (not verified) on 05 Apr 2015 #permalink

This now makes me wonder if my ring neck parrot can taste all the different tastes there is. He seems to prefer sweeter fruit over sour fruit, but I could be wrong. This is very interesting to know, the taste of fish is so unique, I really thought they knew what it tastes like, I hope research will be done on other animals as well to determine if some other animals only have receptors for sweet for example. I am also really glad that we are able to taste everything we eat.

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By Marinda le Roux (not verified) on 05 Apr 2015 #permalink

After doing research I found that the TRPM5 protein is the key component of the biological taste process of bitter and sweet tastes. None of which the penguins can taste. It also functions at a optimum temperature of 15-35 degrees Celcius therefor not working at cold temperatures (Uniprot, 2002), so it makes sense that the problem of penguins poor taste is because of the lack of this important protein. But on the other hand they don't need to be able to taste bitter or sweet so the loss of the function of TRPM5 is not as problematic to them as it would be for a human.
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By A Potgieter 15004512 (not verified) on 06 Apr 2015 #permalink

At first glance I found this peculiar but after further consideration I can conclude that this is highly interesting and informative. Many would conclude that the colder environments that these penguins inhabit would render the the protein 'Tmp5' not to operate at optimum efficiency and thus causing a loss of the three basic types of tastes(as indicated), but the surprising fact is that although a loss would disadvantage a particular organism this however could be seen as a gain as the powers of detection are strengthened to some extent. My sense of disregard has been superseded by gratefulness.
Could the spike-like papillae that is that is found on the tongues have an impact on the degree of loss of these taste-receptors?
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Now I know why my cat just comes to me when I show her their cat food :) Yes, I think this is an interesting research. Like it was said before, it makes sense that cats would rather use their eyes than their nose to find their prey. They have an excellent night sight which increases their rate of catching their prey. What I always wonder, is how they manage to keep quiet enough to remain unnoticed by a mouse, because a mouse has a really sensitive hearing.

Wow!!! wonderful phenomenon and extraordinary to find out about such beautiful creatures. I'm so grateful that we can enjoy such tasteful delicacies.

It is true that we are going to learn new things until our last breath. Well penguins live in a salty environment, obtaining their food there. They sometimes eat dead organisms(sour taste) or feed on their preys(salty taste). As time went by, these penguins they became 'adapted' to these kinds of tastes thus today they are only able to taste sour and salty taste.
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Yes, I agree that the result of this study is really interesting. I would have thought that at least cats have the affinity to detect sweet taste. My grandmother’s cat goes crazy for chocolate. If one leaves a chocolate on the table, she rips it open and eats it. But if she has no receptors that can detect sweet tastes, why does she love chocolate so much?
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I find the fact that penguins cannot taste sweet, bitter or savoury flavours completely fascinating! The fact that penguins cannot taste the fish that they constantly eat is totally bizarre. I can understand why penguins have lost their sweet and bitter taste receptors because they have never used these receptors and never will and so most likely through evolution, the penguins lost these taste receptors. The fact that penguins live in very cold environments lead to their lack of the protein Trmp5 which then obviously lead to the penguins not being able to taste their main food source (fish).

By Aimee Serafini (not verified) on 12 Apr 2015 #permalink

I find the fact that penguins cannot taste sweet, bitter or savoury flavours completely fascinating! The fact that penguins cannot taste the fish that they constantly eat is totally bizarre. I can understand why penguins have lost their sweet and bitter taste receptors because they have never used these receptors and never will and so most likely through evolution, the penguins lost these taste receptors. The fact that penguins live in very cold environments lead to their lack of the protein Trmp5 which then obviously lead to the penguins not being able to taste their main food source (fish).
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By Aimee Serafini (not verified) on 12 Apr 2015 #permalink

Yes, I agree that this result of this study is really interesting. I would have thought that at least cats have the affinity to detect sweet taste. My grandmother’s cat goes crazy for chocolate. If one leaves a chocolate on the table, she rips it open and eat it. But if she has no receptors that can detect sweet tastes, why does she love chocolate so much?
15060188

Yes, I agree that this result of this study is really interesting. I would have thought that at least cats have the affinity to detect sweet taste. My grandmother’s cat goes crazy for chocolate. If one leaves a chocolate on the table, she rips it open and eat it. But if she has no receptors that can detect sweet tastes, why does she love chocolate so much?

Does this research mean that you could feed a penguin anything? Because it cannot detect meaty flavors?

I found out sweet tastes trigger receptors in the human, as well as in the cats body that cause pleasurable sensations. These drive the consumption of carbohydrates and amino acids which are necessary components of healthy diets. But avoid feeding your cat chocolate. It is not healthy for her.

By Bianka Detering (not verified) on 14 Apr 2015 #permalink

This is very surprising, because the food that they depend on to be able to function and to survive is after all fish. I do however wonder if this information is accounted for penguins living in other parts of the world as well. In some parts where penguins is found the temperature isn't necessarily low, will this mean that the Trpm5 protein might work well enough so that they will be able to taste sweet and bitter tastes as well?
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I can agree with the fact that penguins have little taste receptors and in their natural habitat the can only distinguish between salt and sour, but I have some difficulty understanding the hypothesis. if the protein Trpm5 didn't work because of the extremely cold environment, will zoo penguins be able to taste better after adapting? I will rather agree with the hypothesis from Jianzhi "George" Zhang of the University of Michigan which states that penguins have little taste buds and their tongues are used to grab onto food rather than tasting it.
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By Katherine Mcfarlane (not verified) on 15 Apr 2015 #permalink

This is very surprising information, I had no idea that penguins had limited taste. But I suppose if they don’t chew their food and just swallow it they wouldnt taste much anyway! It is also interesting to learn that cats cannot taste sweet. Where does this leave dogs? Can they taste the 5 basic tastes?
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The Trpm5 is a confusing factor to me considering the fact that penguins live in warmer conditions in certain areas of the world however it was quite fascinating to learn that penguins can only experience salty and bitter taste sensations.
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By Charne Coetzer (not verified) on 16 Apr 2015 #permalink

This information is very interesting as these mammalians generally live in such extremely cold areas such as Antarctica yet lack the gene that codes for them to taste fish.Which they consume daily.Indirectly, this protein(Trpm5) works well or better at warm temperatures does this mean that the penguin in South Africa can taste better than the penguin in Antarctica? (u15089054)

By Monique Williams (not verified) on 16 Apr 2015 #permalink

Since the Trpm5 protein works relatively effective in warmer temperatures, what effect is global warming have on the taste buds of the penguins? Will it affect their current diet?

By Kim u15147283 (not verified) on 17 Apr 2015 #permalink

The research done on this topic is very interesting, but when looking at all the penguins the temperature differs from one habitat to another.
Is the taste senses of penguins that lives in warmer temperatures more accurate because of the Trmp5 that does not co-operate very well in cold temperatures?
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By K Combrink (not verified) on 17 Apr 2015 #permalink

This information is astonishing and I never ever thought that some animals do not have all five tastes buds. This leaves a question of if there is a correlation between the different taste buds that have been lost by animals such as cats and the mentioned penguins, referring to the comment of Stellar. I actually feel sorry for penguins that they have less taste buds and can only taste salty or sour tastes.

By Marissa Boshof… (not verified) on 18 Apr 2015 #permalink

This is a very interesting study.

By K Combrink (not verified) on 19 Apr 2015 #permalink

Since the Trpm5 protein works relatively effective in warmer temperatures, what effect is global warming have on the taste buds of the penguins? Will it in affect their current diet?

By Kim 15147283 (not verified) on 19 Apr 2015 #permalink