lobsters, shrimp, crabs and other arthropods, fish, tunicates, echinoderms, mollusks, coelenterates, and the sort would not need to be brought aboard the ark to survive.
Let's see - rain is usually fresh water, neh? And practically the entire list above, except for a few sorts of fish, will die or even "explode" in ten minutes in fresh water. So by what magickal mechanism do we preserve saltwater environments in a freshwater flood? Or, equally important, fresh water environments in all-covering seas? How 'bout those corals, which
require clean salt water and sunlight to survive? Where did they hang out for a year of Flud?