Have Penguins Lost Capacity to Taste Fish?

PenguinsPenguins may have lost the capacity to taste fish, according to a recent study. The research of Penguin genetics seems to suggest that three of the five main tastes were lost during eons of evolution. According to U.S. and Chinese scientists, while taste may be important to the majority of animals, it may not be needed by penguins since they swallow fish. Numerous other birds are not capable of tasting sweet flavors, however, they can taste umami (meaty) and bitter flavors.

Researchers discovered the missing taste genes while decoding penguin genomes.
The University of Michigan and Wuhan University, China, professor, Jianzhi Zhang said that the penguin tongue structure and the behavior of swallowing fish whole point to the fact that penguins may not need taste sensitivity. In addition, a more involved examination of penguin DNA disclosed that functioning genes for the bitter, sweet and umami receptors are lacking in all penguin species.

Zhang said that genetic information indicate penguins lost the capacity to taste fish, but probably possess salty and sour tastes and lack bitter, sweet and umami tastes in a statement to the BBC. The robust, savory taste linked with meat is umami. It comes as a surprise that a carnivorous creature does not have this taste, but it is not that important for the penguin, which does not chew when it swallows fish. It is not certain if these behaviors are the result or the cause of their loss of taste.

Zhang added that the results of the study published in the Current Biology journal are a puzzle. One puzzle clue came from the evolution of the flightless bird on Antarctica’s sheets of frozen ice. At very low temperatures, transmission of signals from bitter, umami and sweet (salty and sour are an exception) flavor receptors to the brain do not function. Scientists say this may have caused the penguin to lose its sense of taste over time.

One species of penguin, the emperor penguin pursues it quarry through waters that are nearly freezing. When it finds its meal of a squid or fish, it latches on to its prey with its very strong jaws and eats it. After all of that expenditure of energy, the penguin does not really taste the flavor of its dinner.

Most birds, like the penguin, are lacking two of the five tastes, sweet and bitter. The hummingbird is an exception. It can taste sweet and lives on nectar. The penguin, then only has two possibilities, salty and sour. Even with only two taste options, Zhang believes that penguins do not have to taste their food, to see if it is nourishing because they can see it swimming, just prior to devouring it.He further added that it is not probable that penguins will gain the umami taste in the near future. Taste began developed over millions of years so that when an animal does develop a different way to taste it looks very different over time. Zhang and his fellow scientist examined five species of penguins and none of the species studied, were able to taste umami.

By Gerald Sowell

Sources

BBC News

NPR

The Washington Post

Photo By Christopher Michel – Flickr License

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