bedrock-samples/behavior_pack/loot_tables/gameplay/fishing/jungle_fish.json

{
  "pools": [
    {
      "rolls": 1,
      "entries": [
        {
          "type": "item",
          "name": "minecraft:fish",
          "weight": 60
        },
        {
          "type": "item",
          "name": "minecraft:salmon",
          "weight": 40
        }
      ]
    }
  ]
}