Fish Breeding

This mod makes fish breedable. Feeding 2 salmon, 2 cod, 2 pufferfish, or 2 tropical fish with dried kelp (by right-clicking on them with it), will cause them to swim towards each other and produce an offspring. 

Most interestingly, it makes it so tropical fish can be hybridised, always passing on at least one trait from each parent, and two from the other parent. Every tropical fish in Minecraft has one of 12 patterns, and two colours. With 16 possible colours, there are over 3,000 combinations. By breeding tropical fish together, this mod makes it much easier to create the tropical fish variant that you want, and would make collecting them all feasible, albeit still challenging.  

In the 26.1.2 version, salmon will also pass on their size to their offspring (Salmon size variants don’t exist in the earlier Minecraft versions).

The mod doesn’t add true baby fish. The offspring are full size. But the offspring will have a 20 minute cooldown before they can be bred, mirroring baby animals taking 20 minutes to grow into adults. The parent fish have a 5 minute cooldown before they can breed again.

Fish will also calm down when the player is holding dried kelp, rather than panicking and trying to flee as they normally would, making them easier to feed. 

This mod also makes it so tropical fish variant information will be shown in the Jade tooltip while looking at the mob. Usually this is only viewable when hovering the item while the fish is in a bucket. 

Full fishclosure: this mod was coded using Claude Code, an AI tool. The mod concept and this description were made by a human.