What would a Mermaid’s taste buds be like?

Question

Assuming Homo Erectus deviated at some point in history, to become Homo Aquarus, would their taste buds have developed different due to the nature of the foodstuff available to them?

Of course, there's no definitive answer, leaving it mostly up to conjecture, so to curb that slightly, let's just suppose our Homo Aquarus has evolved to have the same gustatory perception (and thereof diet) as the Dolphin.

Now, let's assume that our Homo Aquarus makes a brief trip onto land. Would it experience taste differently? Namely, would it be unable to perceive certain flavours? Would sweet things taste bland? Would salty things not taste salty?

Answer 1

How taste is percieved wouldn't necessarily change, but types of foods or tastes that haven't been encountered before or that aren't normally eaten could, possibly, taste like nothing

This is an intriguing question, but before I go into it, I'm going to assume Homo Aquarus may have the same the same diet as dolphins, but that they actually chew their food (if they didn't and just swallowed their food whole, then you could end up with them potentially not being able to discern any tastes besides saltiness, just like dolphins can't)

As far as the diet of dolphins go, they are carnivores, meaning that they pretty much eat the fish and ignore the seaweed. If the mermaids have the same diet, then it's possible that they might not be able to perceive "sweet".

Omnivores from beagles to grizzlies can detect a wide range of flavors and enjoy the taste of sugar. But other mammals with narrow carnivorous diets have been subjected to evolution’s “use it or lose it” decree. These meat-eaters are genetic mutants without working taste receptors for sweets.

One thing to keep in mind that a major reason for taste is to determine what's good/bad for the animal to eat. For something that an animal doesn't need to survive or something that the animal gets second-hand from their carnivorous diet, then it's entirely possible that things like apples would just taste like nothing to them (and therefore be unappealing to eat).

One Other Thought

Another thing that came to mind when I was considering this and considering how some animals can't taste certain things is synesthesia (a condition where a person's senses are "crossed" so that, for example, they don't perceive sweet as sweet, but maybe as the color pink). I'm not sure if it makes sens to incorporate this into your scenario, but perhaps if mermaids can't actually taste the food when they put it in their mouths, then they could see it.

Answer 2

If we take dolphins as our best comparison, as you suggest, they would probably have lost all ability to taste sweetness, savouriness, bitterness, and sourness, leaving them only with the ability to taste saltiness. See this paper on how many different species of whale and dolphin have lost the ability to taste everything except salt: https://goo.gl/bXQcpT

Sweetness and bitterness, in particular, are generally only used to detect the goodness or badness of eating a particular plant. The former indicates it's got a lot of energy; the second indicates it's poisonous. You don't eat plants = you don't need to taste sweetness or bitterness. Not sure where umami factors into that equation, but the basic point is that taste is functional by purpose and enjoyable by coincidence.

You'd also have to factor in the idea that a Homo aquarus (style point: italic for the whole name; caps for the genus; lower for the species) would presumably not cook their food, as I'm unclear how they would create fire. Or boil anything. You could use hydrothermal vents, I suppose, but that opens up a whole new can of worms. Literally.

EDIT: followed advice about PDF files.

Answer 3

It may not be effective at all depending on their diet, The loss of taste occurs in cetacea and seals, but not manatee. So if you're mermaids are purely carnivorous they will likely lose everything but saltiness, loss of certain tastes are fairly common in hyper-carnivores even on land. But if they are omnivores they should still be able to taste normally, taste is more useful when eating plants.