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Adam slug burial at sea.png

Sea Slug concept art.

This little Sea Slug has come along and glued together all the crazy ideas I've had since the war… it doesn't just heal damaged cells, it… resurrects them… I can bend the double helix… black can be reborn white, tall, short, weak, strong…
― Brigid Tenenbaum[src]

The Sea Slug (or ADAM Slug) is an underwater mollusk known to naturally produce a raw form of the volatile genetic material known as ADAM. It is apparently indigenous to the seabed around Rapture and has since spread throughout the Atlantic Ocean. It is utilized in Rapture to create ADAM, and in turn, Plasmids. The slugs' ability to produce ADAM is thought to be the result of a mutation caused by a large Luminescent Biomass in ocean rifts deep below Rapture, which can be seen beneath Persephone in BioShock 2.[1]


Sea Slug Anatomy and Life Cycle.

How do they work?"
"Something about stem cells…
― Rapture Citizens[src]

Living in an underwater city at the bottom of the Atlantic Ocean, the citizens of Rapture encountered marine life in ways they could never have on the surface. One day, biologist Dr. Brigid Tenenbaum observed a dock worker in Neptune's Bounty who had recently regained the use of his hand years after a crippling injury. The man revealed that a Sea Slug brought in from the ocean had bitten him. The interaction with the strange animal had resulted in the miraculous recovery. Tenenbaum retrieved the slug and began to study its amazing biochemistry.[2] Her research would unlock the key to medical and consumer genetic modification and herald the age of ADAM.

In order to produce greater quantities of the ADAM to meet commercial demand for the citizens of Rapture, the slug must go through a symbiotic embedding process, where it is implanted into a small child, specifically, a young girl, aged 5–10 (possibly). Through this procedure, the young girl becomes what is called a "Little Sister," and the slug creates ADAM with the child as its symbiotic host. ADAM is then regurgitated by the Little Sister, which can be processed to make a number of ADAM products for a variety of other uses. In the game, the player can use ADAM from a Little Sister to purchase Plasmids, Gene Tonics, and other improvements at a Gatherer's Garden machine.


Harvesting a Sea Slug in BioShock.

Main article: BioShock

Over the course of BioShock, Jack will obtain Sea Slugs if he chooses to harvest the Little Sisters he encounters. These Sea Slugs, freshly removed from their hosts, are shown to be a brownish-black color, with reddish-orange luminescent spots on their exterior.

BioShock 2[]

Main article: BioShock 2

As in the first game, the slugs are visible during the process of harvesting a Little Sister in BioShock 2, but are only faintly seen. They can also be seen when the player is walking outside in the Atlantic Ocean around Rapture. These slugs, having never been implanted inside a human body, are a clean, pale color with pinkish luminescent spots. They are found lying on the sea floor, gripping walls, etc. Subject Delta can pick them up to supply himself with 10 ADAM per slug. There are five in total.

Locations in BioShock 2[]

Siren Alley[]

Three of them can be found in the beginning underwater section.

  1. On the left of the main path, under the spotlight.
  2. On a wall near the first left turn.
  3. In a pipe between the entrance to Siren Alley and the second slug's location.

Fontaine Futuristics[]

  1. At the beginning of the level, beneath the wreckage of a collapsed tunnel, near a corpse covered in silt from the floor of the ocean.
  2. On the top of the staircase near an Alpha Series corpse, in the underwater section on the way to the hidden Plasmid laboratory.

Minerva's Den[]

A Sea Slug near the entrance to Minerva's Den.

Main article: Minerva's Den

In BioShock 2's downloadable content, Minerva's Den, there are a total of nineteen Sea Slugs to collect. Some of the Sea Slugs are underwater, while others are contained in glass jars. Each jarred Slug is named for one of the developers of Minerva's Den.[3]

Named Slugs[]

  • Brandon
  • Collin
  • Devin
  • Jeff
  • Mario
  • Rinaldo
  • Scott
  • Steve
  • Will


Minerva's Den[]

The first four Slugs can be found outside in the ocean starting point.

  1. On a rock on the right side of the main path.
  2. On a girder on the right when passing the large Minerva's Den sign, just after the first Slug.
  3. On the back of a stone pillar with two blue lights when the player falls down a few feet and sees a staircase.
  4. Go past the above-mentioned staircase and wind around until reaching a stone pillar. It is up on the pillar.

The remaining Slugs in this level are located inside the building and are mostly contained in jars.

  1. Executive Wing: In a flooded employee office near the first Gatherer's Garden. It is inside the storage room next to a Turret.
  2. Executive Wing: In the Boardroom. It is in a pool of water in front of the giant clock.
  3. Executive Wing: In the area locked with a Magnetic Lock. It is located in the back area next to a Turret. Normally, one can only enter this area after obtaining the Gravity Well Plasmid.
  4. McClendon Robotics: In the back office with a Security Camera, inside System Design.
  5. Air-Tite Archives: In the New Accounts office on the second floor of the Archives entrance.


Four of the Slugs in this level are located on the seafloor. The player can obtain them when asked to get the Signal Beacon.

  1. On a big window on the right side after coming out of the Airlock.
  2. Behind a rock underneath some pink corals.
  3. Next to a giant steel door opposite a group of pink corals. One can access this location by turning left when seeing a plant with strange, blue polyp-like buds.
  4. On the top of a rock with an anchor. The player can jump on it from the cliff where the Signal Beacon is located.

The remaining Slugs in this level are located inside the building and are contained in jars.

  1. Entrance: On the back of the reception desk, which is in front of the player when first entering this level.
  2. System Programming: In Felix Birnbaum's Office. It is on a shelf directly opposite the door. One can only enter this room by buying a key from a nearby vending machine outside the room.
  3. Exhaust Venting: Next to the big venting machine. One can find it by turning left and finding the Vacuum Bot.
  4. Climate Control: Near a corpse in a semi-flooded area which can only be entered when crouching.
  5. Climate Control: On a desk in the room with the Climate Control console.

The Thinker[]

  1. On a console on the right side before the entrance to the Maintenance Access Shafts.

BioShock 2 Multiplayer[]

Sea Slugs in the wild advertisment.jpg
Main article: BioShock 2 Multiplayer

An exhibit on Sea Slugs can be found at the Oddities Wing of the Point Prometheus museum map of BioShock 2 Multiplayer. Unlike their other appearances through the series, they appear there in various sizes.

Burial at Sea[]

Sea Slugs in Burial at Sea.

Main article: Burial at Sea

Sea Slugs are also seen in BioShock Infinite's downloadable content, Burial at Sea - Episode 1. While they had most often been seen near the sea floor in previous games in the BioShock series, here it's shown that, given the opportunity, they could travel to relatively high-elevation places around the city. A trio of slugs can be seen perched on an exterior window ledge at the lookout outside The Watched Clock on High Street. A couple nearby are observed wondering about how they function revealing that the average Rapture citizen had at least some knowledge of the slugs' role in the ADAM production process before the Rapture Civil War.

Sea Slugs found in Fink's laboratories.

In Burial at Sea - Episode 2, many tested, stuffed, and dissected Sea Slugs can be seen at the Fink Manufacturing Research Laboratories. It is revealed that Jeremiah Fink sent people to various points in the Atlantic Ocean for expensive underwater expeditions in order to find the ADAM needed to produce Vigors, as heard in the Voxophone No Profit for the Prophets. A chalkboard also shows their anatomy, while another one reveal that hosts are essential in the life cycle of Sea Slugs, reinforcing their parasitic nature.


Behind the Scenes[]

The early gatherer, a sea slug.

  • The drawing of the Sea Slug's anatomy pictured above reveals that the slugs are hermaphrodites like all other gastropods.
  • In the early development of BioShock, Sea Slugs were supposed to be found wandering around and gathering ADAM without the need for a host. Little Sisters were later implanted to the game to give the Gatherers an appearance more appealing to players, one which they could pity and eventually spare them.
  • All of the named Sea Slugs reference the main developers of Minerva's Den. (Steve Gaynor, Devin St. Clair, Jeff Fisher, Scott LaGrasta, Mario DiPesa, Rinaldo Tjan, Will Armstrong, Collin Fogel and Brandon Pham)[3]
  • In BioShock: The Collection, the named Sea Slugs in Minerva's Den are no longer named. The label simply reads "Fresh Water".


  1. Post by Steve Gaynor on the topic "Introduction time! Steve Gaynor, writer/Lead Designer of Minerva's Den in the 2K BioShock 2 Forums
  2. Brigid Tenenbaum's Audio Diary: Finding the Sea Slug
  3. 3.0 3.1 "The Secrets of Minerva's Den" article on Cult of Rapture