"It has been long time said that the behaviours of the merpeoples toward others of their kind and humans, be them Muggles or Wizards, would depend on wether they live in salt waters or sweet waters. I had the chance to meet different specimens of both habitats and I can assure you that I did saw difference.

Near Greece, in the Mediterranean sea, I managed to interact with a small group. It was like they did not trust me, but I believe I struck their curiosity with my two legs, no fins and my incapacity to breath under the water surface. On of them, a female, dared to came out the water, armed with a spear made of what seemed like wood that she might have found floating somewhere with a sharp piece of rock at the tip, and sat on a rock on the shore to look closer at me. But she did not make any physical contact, she only kept looking straight into my eyes. For a reason I still can not explain, female salt water merfolks look closer to humans than the ones living in sweet water. For the males, it is the total opposite, the look closer to the fish, especially their facial structure. But still, I could see a man visage there."

The physiology of the Merpeople is stunning for it varies depending on where they live, just like humans. Not only will their aspect will balance between more fish or more human, their fish tails and skin pattern will also vary. Most comonly see in the Mediterranean sea, the Scombridae family, the Tuna and also the Carangidae family, the Trevally. These specimens of Merpeoples live in large groupe and are deeply united. They fight with great tactics against natural ennemies like sharks and possibly other merfolks clans.
In habitats like coral reefs, merfolks will have patterns of more tropical fish, like the Blue Surgeonfish. Their size will also be slightly smaller, but they can be as agressive and dangerous. Just because its pretty, doesn't mean its not dangerous.

"In a lake of France, who is inaccessible by Muggles, live a clan of Sweet water merfolks. Now I have to specify a thing. Sweet or Salt water, Merpeoples, by nature and because of confrontations between them and the Wizard world, are quite mistrustful of humans, and can still show agressive behaviours. Although, good luck was with me this time again. The clan I am about to talk about showed itself to be very...benevolent and of pleasing nature. This time, the female specimens had a physical appearance going more for the fish. again, the male were the opposite. The looked much more like humans men. the only exception was the eyes. They looked more like those of a fish. They posses beards made of the same thing as their hair and do not posses hair like eyebrows and eyelashes.

Now there is a question to ask. How to they breath under the water? Give me the pleasure to explain this."

Merpeoples have different capacities to extract air from water. Sweet water specimens posses hair, and facial hairs on the males, made of the same material as the classic fish gills. The extract the air from the water that goes directly to the brain. they also posses lungs, same as human's to breath outside the water.

As for salt water, well they do posses gills. Their locations are at the very same place as their ribs. To extract air, the keep their mouth slightly open and "swallow" water that rush to the gill and come out of the water, keeping the oxygene inside the body. But then, why do they have gills made hair? The only theory that was brought was that in case their gills were clogged or broken or any other possibility, well they would have a security mesure to still be able to breath under the water.

If both sweet and salt water posses a great similarity, its that some posses neck gills. Same as the fish gills, they are located on the neck's sides.

Strange fact about the sweet water Merpeoples is that they don't always share similarities with already existing fish species. They can look like no other fish do, blending colors like grey and brown with more warm colors like orage or red.