|Release date||1 October 2015 (Update)|
The respiratory system is encountered during the fight with the Abyssal Sire.
Four systems are found in each chamber. They are protected by several tentacles which will attack players if they get too close to them. In addition, while the tentacles are awake, they will provide a massive defense buff to the systems, making the player's attacks deal 0-3 damage. Once all four systems are destroyed, the player can start the next phase in the fight.
Each system has 50 hitpoints, level 80 in Defence, and is immune to both poison and venom. In addition, it will heal one hitpoint every five seconds. Respiratory systems can only be attacked with magic or ranged, as melee is unable to reach them.
- Prior to the update on 24 August 2017, the slayer helmet did not provide an accuracy and damage buff against the systems.
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