My 6-year-old loves dressing up as a mermaid and is disappointed that she can’t become a mermaid when she grows up. But the thing she really wants to know is, how do mermaids wee and poo?
The trouble is, mermaids are imaginary creatures so there aren’t any real ones that we can study. But if we believe that mermaids are like humans with a fishy tail instead of legs, perhaps we can make a prediction about how they might go to the loo?
When humans and fish eat, food passes into their stomachs and intestines to be digested (broken down). Their bodies takes nutrients from the food to give them energy and help them to grow; the bits they don’t need pass through their digestive systems and come out of their bodies as poo. (Remember my earlier post about what is poo?)
Humans normally use a special place (a toilet) to do their business. They poo out of a hole, called an ‘anus’, in their bottoms; and wee using a different hole. In males (boys and men), the hole is at the end of their penis; in females (girls and women), the hole is between their legs.
Fish also have a special hole, called a ‘vent’, from which their poo comes out. This vent is on the underneath of the fish’s body, close to one of the fins towards the tail end. If you have a pet fish, you might have seen it swimming around with something stringy-looking dangling underneath its body, near its tail? That’s its poo! Eventually the poo string will break off and sink to the bottom of the tank and you’ll clean it out when you change the gravel. Fish wee as well – either through their gills or through a special hole called a ‘urinary pore’.
So how does this information help us to think about how a mermaid might wee and poo?
Well, since a mermaid has a human top half and a fishy bottom half, I think she would poo through a vent on her tail. This would mean that she would make stringy poo like a fish. But because of her human body, she would go to the surface of the water to breathe using her lungs (a bit like a whale does). So, I think she would use a urinary pore for doing a wee because she wouldn’t have any gills.
What do you think? Do you agree with me? Or do you think that a mermaid would sit on an underwater toilet to do her business?!
Since mermaids aren’t real, I can’t share any facts about them but you might enjoy these fun facts about fish instead.