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