Fauna

Fauna is the scientific term for the animals of a region. Fauna in Subnautica can be found all over the planet, from the deepest darkest depths of the secretive Lost River, to the vibrant Safe Shallows, and even to the fiery pits of the lava zone.

There is a large variety of fauna, ranging from the minuscule, cave-dwelling Rockgrub, to the colossal Sea Dragon Leviathan that spews molten minerals from its mouth. Fauna on Planet 4546B are capable of enduring and adapting to various environments, although unable to thrive due to the presence of the Kharaa Bacterium. Certain species of small fauna can sometimes be seen forming shoals. Fauna on 4546B also have yellow blood.

The player can scan fauna with the Scanner, allowing them to view information about the creatures in their PDA.

Reproduction
All known fauna on Planet 4546B are simultaneous hermaphrodites, meaning that they have a single sex capable of playing the role of either the male or female in reproduction, and every individual being able to lay eggs and fertilise them. Two parents are still required to fertilise the eggs once laid, making it sexual reproduction. At least one fauna species is exempt from this and reproduces entirely asexually although the norm for the planet is sexual reproduction, as can be observed in all species that can be placed in an Alien Containment unit who will require twice individuals of their species to produce eggs. All known species on 4546B reproduce via egg-laying.

Invertebrates make up the minority of fauna species on Planet 4546B, around 16.5%, contrasting with Earth on which invertebrates make up around 97% of fauna species.

Future Plans

 * In the future it may be possible to ride certain fauna.

Trivia

 * Fauna were once intended to posses inherent attributes, that would have caused them to exhibit unique behaviors. These included, e.g., "Fertile" (occasionally lay eggs that can be hatched), "Alpha" (attacked the player if other creatures were killed by the player in the immediate vicinity), "Complex" (specimens take longer to scan), "Greater" (specimens are of larger size and weight), ... Whether these attributes are currently implemented or will be implemented in future updates is unknown.
 * As of the Dangerous Creatures update, all fauna have yellow blood. Before this update, fauna had red blood. This is due to the ESRB giving Subnautica a higher rating than expected due to red blood.
 * If you hold a small animal in your hand when a carnivorous fauna is about to attack, it will eat the animal out of your hand, instead of attacking you.
 * It seems to be possible to stop small fauna (like the bladderfish) from spawning by catching every single one of them. The console could be used to spawn new ones, however it is uncertain whether this will increase the population over time.
 * In the very early stages, there was an unused Sandworm that could only be spawned using the console, it would stay in one place under the ground and when the player or an npc was right above it, it would spring up and would do 1 damage but at a very fast rate. It never had any animations, except it shooting out of the ground and back into its hole.
 * There was also an unused Grabcrab that would leave its burrow and search for items to drag back to its hole. Its burrow also had the same model as the Grabcrab.