This miracle was Jesus' way of saying that shellfish were no longer a forbidden food under His covenant. In the short Gnostic Gospel of Crustacius, we hear a story that comes right after Jesus blessed Simon Peter with the plentiful catching of fish, where a group of crabs then wander close to their nets.
>Peter looked at the crustaceans curiously, and then to Jesus Christ, as the Christ walked into the water, His skin soon forming a shell around Him, and pincers forming in place of His limbs. Before the onlookers knew it, Christ became part-crab, and said "This is a form of my body, and for all of this blessed Covenant, you may feast on these creatures to remember me". As a shrimp then flopped out of Peter's fish-filled net, Christ, seeing this, went deeper into the water, under it, and emerged out of it soon after, to the amazement of Peter, James, and John, and a large crowd that had gathered around the great sight, as part-shrimp. "So too can you eat shrimp as well, I guess, if you really want to. In fact, go ahead and just eat any shellfish, fine by me". And so, Jesus taught His followers that shellfish were no longer forbidden.
In seriousness, I can only really say "maybe". We don't know for certain. They weren't made in the image of God, unlike humans, so they aren't capable of spirituality, but the New Earth could certainly have animals on it, if God wills it to be. We really will just have to see for ourselves.