Penguins have poor taste

Image from birding.about.com (http://birding.about.com/od/birdfeeders/fl/What-Do-Penguins-Eat.htm)

Image of penguin from http://birding.about.com/od/birdfeeders/fl/What-Do-Penguins-Eat.htm

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

Comments

  1. #1 Shannon Nicol
    South Africa
    March 1, 2015

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

  2. #2 JacciR
    Cape Town
    March 10, 2015

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

  3. #3 Isabela de Castro- U15020623
    March 11, 2015

    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.

  4. #4 E. Bosch
    March 12, 2015

    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.
    u15011781

  5. #5 Tumiso Monaiwa U13412214
    March 16, 2015

    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
    U13412214

  6. #6 Tayla Rabie u15090885
    March 16, 2015

    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.

  7. #7 Quinton R.
    March 22, 2015

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

  8. #8 TIISETSO MAOKA-u15065635
    tuks
    March 22, 2015

    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.

  9. #9 Paige Derbyshire
    South Africa
    March 28, 2015

    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.
    u15026397

  10. #10 Anthony Micklesfield
    South Africa
    March 30, 2015

    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

  11. #11 tebogo(14169101)
    March 30, 2015

    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
    14169101

  12. #12 Cherise Swanepoel
    South Africa
    March 30, 2015

    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.
    15000983

  13. #13 Kaycee Skinner
    March 31, 2015

    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 ?

    u15102808

  14. #14 Liza van Rooyen
    March 31, 2015

    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?
    15030343

  15. #15 Olga Neveling
    March 31, 2015

    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

  16. #16 Thembekile Mkhuzangwe
    South Africa
    March 31, 2015

    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?

    14111782

  17. #17 AS Blecher
    April 1, 2015

    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.

  18. #18 EP Blignaut
    South Africa
    April 2, 2015

    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

  19. #19 R van der Walt 15034365
    April 2, 2015

    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.

  20. #20 Vormaurer, K.F. (u15002782)
    University of Pretoria
    April 3, 2015

    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?

  21. #21 An-zelle Lubbe u15195253
    South Africa
    April 4, 2015

    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?

  22. #22 Jamie Mollentze
    Midrand
    April 4, 2015

    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.
    15086128

  23. #23 Anita van Deventer - u15157947
    University of Pretoria
    April 6, 2015

    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?

  24. #24 Marinda le Roux
    April 6, 2015

    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.

    15017347

  25. #25 A Potgieter 15004512
    April 6, 2015

    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.
    15004512

  26. #26 T.Moolla
    South Africa
    April 7, 2015

    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?
    u15128033

  27. #27 Antje
    SA
    April 8, 2015

    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.

  28. #28 Oliver
    Gauteng
    April 11, 2015

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

  29. #29 Sunnyboy
    University of Pretoria
    April 12, 2015

    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.
    u15297307

  30. #30 AC Menne
    SA
    April 12, 2015

    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?
    15060188

  31. #31 Aimee Serafini
    April 12, 2015

    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).

  32. #32 Aimee Serafini
    April 12, 2015

    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).
    15170846

  33. #33 AC Menne
    April 14, 2015

    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

  34. #34 AC Menne
    SA
    April 15, 2015

    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?

  35. #35 James
    April 15, 2015

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

  36. #36 Bianka Detering
    April 15, 2015

    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.

  37. #37 N Smith
    April 15, 2015

    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?
    15021824

  38. #38 Katherine Mcfarlane
    Centurion
    April 15, 2015

    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.
    u14224781

  39. #39 Stellar
    Pretoria
    April 16, 2015

    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?
    14020123

  40. #40 Charne Coetzer
    Pretoria
    April 16, 2015

    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.
    14010926

  41. #41 Monique Williams
    Pretoria
    April 16, 2015

    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)

  42. #42 Kim u15147283
    April 17, 2015

    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?

  43. #43 K Combrink
    UP
    April 18, 2015

    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?
    (u15039316)

  44. #44 Marissa Boshoff (15037356)
    Pretoria
    April 18, 2015

    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.

  45. #45 K Combrink
    UP
    April 19, 2015

    This is a very interesting study.

  46. #46 Kim 15147283
    April 19, 2015

    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?