Should I feed frozen brine shrimp to my baby zebrafish?
No. Frozen brine shrimp are considered a non-optimal food for a number of reasons. The freezing process damages the shell of the shrimp resulting in the loss of nutrients. The shrimp will become food for bacteria or fungus, both bad. The frozen brine shrimp are dead so they will start rotting immediately and sink to the bottom where they will be a less attractive food item for the fish. Instead, you should use live baby brine shrimp that you hatch yourself from eggs (cysts actually). These will swim around a bit, eliciting interest from the fish, and will provide a fresh source of food.
