Deep Shroom

The Deep Shroom is a hazardous flora species found in abundance in the Blood Kelp Zones and their caves, in small clusters, and in the Lost River and the Sea Treader's Tunnel Caves. It is a relative of the Acid Mushroom, and is used as a raw material in the manufacturing of Hydrochloric Acid.

The player can pick up Deep Shrooms by hand, or strike them with a knife to destroy them. This causes 8 damage to the player and surrounding flora and fauna due to acid being released into the water and gives the player four Deep Shroom Spores.

The Deep Shroom and its spores can be planted in an Exterior Growbed or an Alien Containment, and will not deal damage when harvested with a knife.

Appearance
The Deep Shroom appears as a stout mushroom with a white cap, becoming pink towards the center, and a dark grey stem. It is similar in shape to its relative, the Acid Mushroom, as they share the same model but have different colorations.

Behavior
Like the Acid Mushroom, the Deep Shroom possesses highly acidic compounds in its flesh that leach into the water if its skin is pierced. As such, harvesting spores from the Deep Shroom with a knife triggers its acidic flesh defense, dealing 8 damage to the player and surrounding flora, fauna, and structures, as mentioned earlier.

It is possible for a Deep Shroom being destroyed to cause a chain reaction, damaging other surrounding Deep Shrooms enough so that they burst as well. This chain reaction can instantly kill a player, wreck a Seabase or heavily damage vehicles, so it is advised that the player separates Deep Shrooms before harvesting their spores.

Deep Shrooms will shrink upon fluctuations in the local water pressure such as if the player approaches them, and will return to their original size if the player holds still or leaves the area. The Acid Mushrooms had this actoin but was cut from the game.

Trivia

 * The difference in coloration between the Deep Shroom and the Acid Mushroom is an evolutionary mechanic which is also found in many other flora and fauna species in Subnautica as well as many real-life animal and plant species in which there is a loss of pigmentation due to restrictions in available nutrients.
 * Some Trello notes refer to the Deep Shroom as the Ghost Mushroom.