This is the map of the seyloid home planet I made a few years ago, which I wiped along with most of my work during my biggest mental breakdown.
Unfortunately I don't remember what info I had added to the old post.
This map shows the Imperial seyloid Capital - visible from space due to its colossal size - and all territories occupied by seyloids.

Copy-pasta some info I have on file about the species :
SEYLOID PLANET NAME - MAKHAMI

Seyloid Population :
• Capital - 2,4 billion
• Outsider Territories - 12,2 billion
• Colonies - 0,6 billion
Seyloid Planet :
• Capital - 6,856,000 square km

Seyloid Lifespan and Age groups
Average Lifespan : 125 years
Age groups :
• Infant – 0-2
• Child – 2-12
• Teenager – 12-24 (Sexual maturity between 16-22)
• Adult – 24-70 (Prime age)
• Aging seyloid – 70-100
• Elder seyloid – 100-140

The Imperial / Outsider division :
Some 2500 years after surfacing and exploring the lands connected to their oceans, seyloids begin to divide into two separate peoples.
The ones interested in invention , technology and science lay the foundations of the Capital. It starts off as a small village, but over the course of 800 years it develops into a massive, progressively expanding city which they call "The Capital". The city's inhabitants call themselves "Imperials" – a leftover term from a short-lived underwater dynasty.

Toxic Ocean:
A huge underwater cavern, spewing lava non stop, poisons the water around it and causes it to boil for thousands of kilometers. It frequently causes earthquakes and tsunamis that hit the surrounding lands and the area it affects is completely uninhabitable for seyloids.
The Outsider communities believe a deity is making the area inhospitable as punishment for seyloids' surfacing on land although that belief has for the longest time been debunked by Imperials since the moment technology allowed a survey the underwater landscape.

The hostile continent:
During the seyloid surfacing it was discovered that the lands of the Eastern Continent are swarming with massive predators, which made settling there impossible.
After a successful migration inland on the Western Continent spanning hundreds of years, seyloids discover that the massive beasts in the East don't venture West frequently due to lack of animal life that can sustain them.
As seyloid technology advanced over the centuries their expeditions east became more frequent in attempts to study the environment, plant and animal life there.
Most of said expeditions end up in disaster as a lot of the adventurers end up getting killed and eaten.
The continent became taboo for Imperials who decided it's best to set up a defensive perimeter on the land bridge between the two continents in order to protect their civilization as it expanded throughout the West.