So you remember that journal about mermaid subspecies, if not here's the journal
https://www.furaffinity.net/journal/9498750/ decided to make them into drawing.

Sunlight Mermaid
These mermaids are up in the sunlight zone. They are the most human looking. These were the one that sailors told tales of. They eat sea plants and plankton. They also can talk to the marine life.

Twilight Mermaid
These mermaids are in the twilight zone. They are a little larger and a little fishier. The sunlight and twilight mermaids time to time cross paths and are peaceful to one another. They plants, plankton, & also some fish. They can't talk to marine animals but they can also do a special echolocation to find fish.

Midnight Mermaid
These mermaids are in the midnight zone. They are a lot larger than the first two and are more fish looking. If they cannot find food than they would eat twilight mermaids or their own. They eat squids, fish, & Sea stars. They can't talk to the other mermaids.

Abyssal Mermaid
These mermaids live in the abyssal zone. They are no longer human anymore. They will eat anything that moves in there path. They don't talk but make gargling noises and a high pitch when they find prey and Kills it. Their arms grab things to eat later.

Hadal Mermaid
These mermaids live in the hadal zone or in trenches. These are the largest mermaids. They are very rare to see but are very dangerous. They eat anything. Nobody knows of these mermaids because of their rareness and being deep in the ocean. They mimic anything that has a noise to get their prey but for the most part they are silent.