Reaper Leviathan Eggs?

[Neato Burrito]

So far, almost all species in the game have some sort of egg or can be assumed to breed and lay eggs. However the Reaper Leviathan (and Sea Treader) are kinda confusing. There's no mention of eggs or anything. I can assume the the dunes is where they belong. (Moutains Island and Crash Site are loud and likely attractive to them). So maybe the birth their young alive? They're not neccesarily mammals, but some sharks can also do the same. Same thing with Sea Treaders, they do travel in some sort of pod, and the younger generally stay put in the middle, similar to mammals.