Spider cracks in transmission

I have these spider cracks in the tail transmission housing. They don't go through and no oil is leaking from where they are. Do we think they will be a problem?

 

That's a pretty normal side effect from the casting process at the factory. An actual crack would be deeper and darker.

 

It's fine, just from when it was cast, most cast stuff that isn't visible is left like that to save costs.

 

As was said casting marks .
No need to add more labor and cost to make it look pretty.

 

Its all back together now, thank you all