Trying to remember an old scifi book that I once read. It was pretty old maybe from the 1950s or 1970s. One of those pulp books. It was a red faded book about a young boy working with his parents and uncle on an ocean research station studying alien life in Earths or one of the Solar System planets seas that were transplanted. One of the lifeforms was a giant monster humanoid herbivorous sea mole that was the size of a whale. I think it was from Mars. At one point the sea mole or digger fought a sperm whale in the sea. There was an ongoing plot of xenophobic terrorists targeting the research outpost due to their paranoia on alien life despite the creature being harmless unless provoked. Does this ring any bells?
I've been going around looking at a few species most notably the Immortal Species, a few races though I have noticed are ones who have a very long rate of maturity, that is species that do not mature for years or even decades. This is just a though idea but maybe we can create a category for this type? Don't exactly have a word to describe this category but I'm sure there is one, a scientific one.