Merpeople

Merpeople are a unique people. These creatures are freshwater subaquatic animals that never naturally surface. These creatures typically live in Living Aquifers. Living Aquifers are an article in itself, but suffice it to say they are grassy underwater lakes filled to the brim with vegetation, lit by Quartz Sunstones. Serene environments by any standards.
Merpeople inhabit these subterannean aquifers. Many of these aquifers stretching hundreds or even thousands of miles, it's quite an expansive land, comparable to Human lands. Although, Human lands have the benefit of having traversible sea nearby and not hard rock. Merpeople are stuck between the walls, but don't particularly need the expansion, as constant wars keep the population in check. 

 
Merpeople, physically, are half Human half fish. Their lower half, seperating just underneath where the reproductive organs are, is a fish tail. The upper part of the tail has a dorsal fin to stabilise the merperson, as well as the tail that is the main force. To move, merpeople move their tails up and down in typical fish fashion. 
Merpeople society is similar to Humans in many ways. Being fairly smart, around 100 iq, just ten points below the average Human, they are quite ingenious and know many things, including a great array of magic. They, however, don't know how to weld and shape metal, as they cannot create reliable fires and the small volcanic ruptures are too hot to venture near without being burned or boiled alive. 
Despite this, they manage a fairly civilised society. Individual rights exist, slavery exists, property rights exist, in many ways it's superior to many Human nations. However, this varies from country to country, but mainly those are the norm. Unlike Humans, there are no races of merpeople, so they live in relative harmony with each other, the only difference being nationality. 
Merpeople society is divided into hundreds of smaller states and a few bigger ones. Typically this varies by cavern or by portion of cavern. For example, the Helinski Cavern may be owned by Helinski, but Helinski could also own the Harbtrop Cavern or the Dorbsvad Cavern. These smaller nations with one or two caverns are known as "States" and the larger ones known as "Empires."
The Merperson's diet consists of fish and kelp, typically. The richer they are, the wider variety of ingredients they have, but it's typically consistent in the two staples: Fish and Kelp.
Most of the farming is based around Kelp. One of the more standout features of the Caverns are the vast, neat forests of kelp strands. Often cubed or in zones, the sections of kelp farming areas are quite a beautiful sight to see. This, as well as the many structures and houses, typically consisting of small caves with circular entrances and smaller circular windows. These can vary in shape and size, but are typically fairly small, just big enough to live and sleep in, similar enough to a Human peasant's house. 

  The castles are made in much the same way, with soft, round architecture and maze like interiors. These are intended to disorient enemies and perhaps get them lost. 
The "Vault" is where everything is stored in the castles. It typically contains food, valuables, and some areas for the royals to sleep in, as well as some for guards. It's a 'last resort' area that can be retreated to if necessary. These have saved a great many royal families.

Basic Information

Anatomy

Half Human half fish, with a dorsal fin on the back.

Genetics and Reproduction

Same as Humans, as their reproductive organs are above their tails, but the females lay two to three eggs instead of having a live birth.

Growth Rate & Stages

A young mermaid slowly grows, shedding it's tail several time before adulthood.

Ecology and Habitats

These creatures can live in any freshwater pond but thrive in aquifers under decent amounts of pressure.

Dietary Needs and Habits

These creatures are omnivorous.

Additional Information

Average Intelligence

These creatures hover at 100 IQ, near the Humans at 110 average IQ.

RARITY: EXTREMELY RARE

Scientific Name

Pisces Homo

Lifespan

45 years due to the pressure

Average Length

7 feet long, including tail, typically