Uploaded image for project: 'Minecraft: Java Edition'
  1. Minecraft: Java Edition
  2. MC-134702

Fish spawned from buckets count towards the aquatic mob cap


    • Icon: Bug Bug
    • Resolution: Fixed
    • Minecraft 18w33a
    • Minecraft 1.13, Minecraft 18w32a
    • None
    • Confirmed


      You can fix this issue for yourself by installing the attached ocean_reviver.zip datapack to your world. This datapack sets PersistenceRequired for all mobs spawned by buckets to 1b, so that they no longer count towards the mob cap.

      The bug

      If there are at least 16 fish spawned from buckets anywhere in loaded chunks (that might be the spawn chunks, chunks loaded via /chunk, or chunks that players currently are in), no aquatic mobs (fish, dolphins, and squid) will spawn anywhere.

      How to reproduce

      1. Create a new superflat world (I chose "Redstone Ready") and change it so that it has biome minecraft:ocean
      2. Run
        /gamerule doMobSpawning false
      3. Create a big aquarium at spawn
        /fill ~ ~-1 ~ ~20 ~-21 ~20 water
      4. Drop 16 salmon from buckets in there
      5. Teleport to somewhere far away, for example
        /tp 1000 56 1000
      6. Check that all salmon still are there
        /execute if @e[type=salmon]
      7. Create a big aquarium there as well
        /fill ~ ~-1 ~ ~20 ~-21 ~20 water
      8. Run
        /gamerule doMobSpawning true
      9. Notice that no mobs spawn there whatsoever
      10. Run
        /kill @e[type=salmon,limit=1]
      11. Notice that suddenly, there are many mobs spawning in that aquarium

      How to fix this bug

      Change the aquatic mob cap so that fish spawned from buckets no longer affect it.

      Original report

      As stated tropical fish and pufferfish are not spawning whatsoever in my main world. I created another world to see if they would spawn there and they spawned just fine. I have spent hours upon hours in my main world and I don't want to have to restart. Is there any way to fix this? I don't know if it's a factor, but I had to travel a fair distance from my spawn point to find warm ocean.

            rockenroll4life rockenroll4life (Josh Letellier)
            Alalia Mary Johannah Lane
            21 Vote for this issue
            15 Start watching this issue