dimedollahs

can you put more than one crab in a tank ? And can you mix crabs with lobsters, shrimps, or crayfish

hey everyone, I am looking to start a 90 gallon predator tank with fresh water barracudas. If anyone has any information about barracudas it would be greatly appreciated. example of information i am interested in : - the size they grow to and how long it takes for them to reach full growth from say 2" long - how many i could keep in a standard 90 gallon tank - could i combine a school of other predators with them such as piranha or gars any other information or tips on the barracudas would be greatly appreciated