Crafting Fillet Knives and Preparing Fish Dishes
This guide explains how to craft and use fillet knives, and how to prepare various fish-based foods. Aquaculture 2 expands the fishing system by adding many new fish types, some of which can be found swimming in the wild. These fish can be processed into fillets.
Fillet Knives
Fillet knives are tools used to process caught fish into 
Raw Fish Fillet. The amount of fillets obtained depends on the fish. There are several types of fillet knives, each crafted from different materials. All fillet knives use two units of their primary material and one wooden rod.
Wooden Fillet Knife: Crafted with two 
Oak Planks and one #c:rods/wooden.
Stone Fillet Knife: Crafted with two 
Cobblestone and one #c:rods/wooden.
Iron Fillet Knife: Crafted with two 
Iron Ingot and one #c:rods/wooden.
Gold Fillet Knife: Crafted with two 
Gold Ingot and one #c:rods/wooden.
Diamond Fillet Knife: Crafted with two #c:gems/diamond and one #c:rods/wooden.
Neptunium Fillet Knife: Crafted with two 
Neptunium Ingot and one #c:rods/wooden.
Fish-Based Foods
Once you have Raw Fish Fillet, you can use it to create other food items.
Sushi: Combine one Raw Fish Fillet with one 
Seagrass to make Sushi.
Turtle Soup: Combine one 
Box Turtle, one 
Water Bucket, and one 
Bowl to make Turtle Soup. The Box Turtle can be found in swamp biomes.
Where fillets come from and go
The knife turns a caught fish into a Raw Fish Fillet, and the fillet is the item every cooking method takes. All three appliances — campfire, furnace and smoker — accept it and return 
Cooked Fish Fillet, so the knife is the only mandatory tool in the chain.
By-products worth keeping
Filleting and fishing both produce items most players throw away:
Fish Bones craft into three Bone Meal
Brown Shrooma crafts into five Brown Mushroom
Jellyfish smelt into a 
Slimeball- A
Tin Can smelts into seven Iron Nuggets
Five mushrooms from one shrooma is the standout — it makes fishing a legitimate way to start a mushroom farm without finding a mushroom island.
The scale of the mod
Aquaculture 2 is 129 pages built on 51 crafting recipes, with only five blocks among its 124 items. It is an equipment and food mod rather than a building one, which is why nearly everything you make is held rather than placed.
Version parity
Recipe counts are identical across 1.21.1 (2.7.21) and 1.20.1 (2.5.7) in every category, so no dish or tool is version-locked.
Covers the mod’s in-game guide topics: Wooden Fillet Knife Stone Fillet Knife Iron Fillet Knife Gold Fillet Knife Diamond Fillet Knife Neptunium Fillet Knife Sushi Turtle Soup