In the Wild

Brine shrimp (Artemia saline) is a type of shrimp that requires salty water (brine) to survive.  It can be found in abundance in the Salt Lakes of Utah (America). 

Only a few other species of animal can live in these lakes due to the high levels of salt (they were originally seas at some point in history).  There are no fish in the lake, but millions of brine shrimp.  They can grow up to half an inch long, living on the reddish brown algae in the lakes.

The main predators of brine shrimp are birds, as they subject to same living environment.  These same birds also provide a means of dispersion for the brine shrimp cysts when they are carried unknowingly to other hatching sites.  This is good protection for the species against reliance of a specific body of water.