How big do brine shrimp get?

I know they are usually hatched and then immediately served as food but I was just wondering how big they get, how long it takes to get them to maturity and how nutritious they are as young adults? It seems to me that using adult brine shrimp would be safer - probably more nutritious - than most of the feeders I have seen in the lfs.

yes..but I heard that mollies were low on the nutritional scale. They are easy to raise though...and my red devil used to delight in chasing them...I felt like I should have played music during feeding time...something like victory at sea!