In order for seafood to be considered kosher it generally has to have a fin and scales which squid does not. There are many other types of seafood that you will be able to include in your Passover dinner though, such as salmon, trout, carp, herrings, tuna, and many others.

As long as the fish you are using has scales and a fin you should be fine to use it in your Passover dinner. Those who are planning this very special dinner will definitely need to be aware of which foods are considered to be kosher and which are not.