Talk:Ghost Leviathan/@comment-33904873-20180109161326/@comment-1478071-20180123060600

Yes and no. I'm about to give you an oceanographer/marine biology lesson.

On land there is a cap on how large a creature can grow before they start getting crushed by their own weight from gravity. Puertosaurs were at the physical limit of land animals needing not only a massive amount of food but also higher concentrations of oxygen than the present atmosphere provides and they also needed an extremely high blood pressure to pump enough blood through their body.

But we're talking about aquatic creatures. Theoretically an aquatic or sub-aquatic creature can grow indefinately given a few variables; enough space to grow and feed, enough food to sustain itself, and little to no competition (as in little to no predators and little to no rivals competing for food). However the larger the creature gets, the more food it needs to survive. And this is where things get complicated in marine biology.

A creature's size and diet greatly reflect on the scale of other creatures around them. For example: the blue whale is massive even by the standards of dinosaurs and is a filter feeder. Plankton, shrimp and microbes are ever present and provide the whales enough food to survive. However if the blue whales were instead carnivores in today's ecosystem, they wouldn't be able to survive because of their scale compared to the sizes of their theoretical prey around them. At best they'd try to prey on large shark species such as great white, basking, and whale sharks and other species of whales. However the blue whale is not fast enough to catch these smaller, more nimble creatures but even if it managed to make a kill, wouldn't get enough sustainence out of each meal. Therefore it would expend more energy hunting than it would regain from eating.

So taking this knowledge into Subnautica we see that the Ghost Leviathan is a territorial filter feeder. Per its size it could be a carnivore but its size would be detrimental as all of its prey would be on the volcanic crator thus limiting it's mobility. Second, as a carnivore, it would need to eat nearly constantly in order to survive. It's diet would consist of mostly Ampeels and Crabsquid and other medium sized predators with an occasional Reaper here and there. However with its near constant need to hunt, this would bring it into competition with other Ghost Leviathans as they need to hunt in the same ~3km by ~3km area. Thus making survival for the Ghost Leviathan very tough. The current apex predator, the Sea Dragon, has a hard time surviving due to its lack of natural prey (which died out due to the Kharaa) causing them to prey on the much, much smaller Crimson Rays and Lava Lizards and occasionally surface to grab a Reaper just to barely get by. This is likely why there are only two Sea Dragons on the map, there may be others surviving in areas we can't visit in game but it's likely they're near extinct as a major loss of their primary food source and severe competition would cause those unable to catch Reapers to starve. The surviving Sea Dragons could have resorted to cannabilizing deceased Dragons or outright killing them in a need to survive, but there isn't evidence to support this. And the Sea Emperor is an intelligent, sentient filter feeder so it doesn't need much explaination. However, if it wasn't trapped in the PCF and it survived like it did well beyond the height of its natural lifespan, it would have been much larger than what we see due to being confinded in an enclosed space. Ancient creatures like the Ancient Leviathan and monolithic Gargantuan Leviathan likely survived as carnivores despite their ridiculous size do to likely having much larger organisms to feed on than what is present in the modern day 4546B.

I hope I may have educated you. Thank you.

TLDR: Yes and no. The bigger animals get in water, the more complicated things become for them to survive.