Seafood Festival

This real world ad that SouperSalad used had some obvious areas that I was able to see, mainly they were there in that fashion as it is used as an advertisement, meaning it needs to be attractive yet, get the point across.
1. Seafood is an excellent source of protein, is low in calories,...
2. Commas seem to be used appropriately i most of the sentences, to show that the information is important.
3. Crabs have 5 pairs of legs, rather five pair of legs would be more appropriate. The em dash after walking legs tells us to read the following sentence, it is important to know that the first set are used for defense.
4.Flamingos are pink because they eat shrimp. Or Flamingos are pink, they eat shrimp. The transition ties the two sentences together as one needs the other to make the statement or reason.