Races of the Source vs the First and those unique to each

[MrThinker]

/snip
Source only:

Sylphs
Ixal
Garleans
Lupin
Namazu
Kojin
Ananta
Qiqirn
Mamool Ja
/snip

Through a quest (main or side I dont remember) in Rak'tika, we actually know that namazu did indeed live on the First. The image of one is found on a ronkan coin that we find. That they can't be found simply points to them becoming extinct in the wake of the Flood.

Also the Amal'jaa equivalent are called the Zun.