They are not the same. The freshwater shrimp I was speaking about are related to marine shrimp in the Order Decapoda. These are the Caridean shrimp which are also known as grass shrimp, river shrimp, etc. The term "freshwater shrimp', as used in your context, is a generic name for many types of freshwater crustaceans in many families and many orders.

Scuds are amphipods in the Order Amphipoda but many call themn "shrimp".

The "true' shrimps are in the Order Decapoda along with crawfish, crabs, lobsters, etc. These have 10 legs.