I seemed to notice that Lox spawns are lower, perhaps since you can breed them now, which I had to start doing because of their seemingly lower rate in the spawners? Before, they seemed to spawn quite frequently in my seed and I could stock up on meat--filling chests. I began to start emptying my stock quickly since the update with Lox breeding, hence again the need to resort to animal husbandry...to refill my coffers.

You mean respawn ?

Yes

yes respawn, how long it take for respawn?

No idea, i mean it is random

Takes like 1000-1500seconds to respawn in the area where you killed them

Most spawn points in the Plains have a chance to spawn Fulings, Deathsquitos or Lox. It is random.