>Traveler Mermaid

Travellers migrate a lot and dwell on land a lot. They have strong flukes to travel long distances and their tails consist of mainly blue colours with extra fins for speed and balance. Though, they can only swim to about 1,000 meters, these mers have strong relationships with dolphins and other aquatic mammals. Their kind, friendly nature makes them great to be around

>Arctic Mermaids

Atlantic mers live in the Arctic circle but are also common in other very cold climates. Their bodies carry flubber to keep them warm, as well as other insulation. They have icey personalities, with ice-like tail colours, such as ash, light blue and white. These mermaids have strong muscles, fangs and claws and enjoy eating squid

>River Mermaids

Also known as The Lara (Brazil) or Water Woman (Native America). They are strong, romantic, mysterious and kind with tears that are said to grant wishes. Their tails come in murky colours such as shades of green, brown and blue to blend into their freshwater surroundings. They are also said to be immortal

But that's just a theory A STUPID THEORY