Darwin Fish
Fish breeding, new features and crafts!
- Loaders
- NeoForgeForge
- Downloads on Modrinth
- 242
- Followers on Modrinth
- 0
- versions
- 3
- Updated
- May 10, 2026May 10
- Published
- in 2026
At a glance
Needed both in the game and on the server
DarwinFish
DarwinFish is a mod that overhauls the underwater ecosystem in Minecraft. It replaces static fish behavior with a dynamic lifecycle, introducing breeding mechanics, genetics, a food chain, and new culinary options.
🐟 Ecosystem & Breeding
Fish now have a complete lifecycle, from eggs to fry to adults.
- Manual Breeding: Feed two adult fish Seagrass or Kelp. They will form a pair and lay eggs on the bottom of the water body.
- Natural Breeding: (Can be toggled in the config). When enabled, fish will automatically graze on underwater vegetation and lay eggs without player intervention.
- Growth Cycle: Eggs take exactly one in-game day to hatch into fry (baby fish). The fry will take another full in-game day to grow into adults. All timings are fully configurable.
- Overpopulation Control: To prevent lag, the mod tracks the number of fish per chunk. If the population exceeds the configured
OVERPOPULATION_TOLERANCE, fish will trigger survival instincts—they may start attacking each other or eating unattended eggs to balance the ecosystem.
🧬 Tropical Fish Genetics
Breeding tropical fish now utilizes a genetics system.
- Offspring inherit the base color, pattern color, and body shape from their parents.
- The physical egg blocks placed on the ground will also dynamically change color based on the parents' genetics.
🐊 New Predator: The Pike
To keep the prey population in check, the mod introduces a new freshwater predator—the Pike.
- Diet & Hunger: Pikes actively hunt to survive. If natural breeding is disabled, a pike needs to eat 2 random fish per in-game day to avoid starving.
- Breeding: In natural mode, a pair of pikes will lay eggs after successfully hunting. For manual breeding, you can feed them raw fish.
- Smart AI: Pikes are not mindless killers. They will not attack other adult pikes or their own fry.
- Player Danger: Pikes will defend themselves if attacked. A hungry pike might also bite a player if they get too close (damage scales with world difficulty).
🍳 Culinary & Items
The mod expands what you can do with fish and their byproducts:
- Harvesting Eggs: Right-click on placed fish eggs with an empty Glass Bottle to safely collect them.
- Caviar Sandwiches: Craft a Glass Bottle of Fish Eggs with Bread to create a highly nutritious meal.
- Cooked Tropical Fish: Tropical fish can now be cooked in a furnace or smoker.
- Fugu (Pufferfish) Preparation: Pufferfish and their eggs are highly toxic, even when cooked. To safely consume them, you must wash away the toxins by right-clicking a Water Cauldron while holding the pufferfish/eggs. This gives you a "Cleaned Pufferfish", which can then be safely cooked and eaten.
Configuration
Most features can be tweaked via the mod's configuration file (darwinfish-server.toml), including natural breeding toggles, growth times, and overpopulation limits.
You can contact me in the Discord: https://discord.com/users/790496483949412373
FAQ
How to install Darwin Fish?
Install NeoForge for your Minecraft version, download Darwin Fish for the same version and loader, put the file into the mods folder and launch the game with the loader profile.
Which Minecraft versions does Darwin Fish support?
Darwin Fish has builds for Minecraft 1.20.1, 1.21.1.
Is Darwin Fish needed on the server?
Needed in the game and on the server