No.
Jews cannot eat shellfish because they don't have the characteristics of a Kosher aquatic being. Any living organism that lives in the sea needs to have fins and scales to be Kosher. Shellfish have neither fins nor scales.
Most squid will eat crustaceans.
Yes are shark does eat a crustaceans.
They eat fish, squid ,crustaceans and salp. they also eat you
Some crustaceans eat shrimp.
They eat fish and crustaceans
No.
Yes.
they eat prawns
small fishes
alge
it its crabs and crustaceans
They eat small fish, crustaceans and mollusks.