Mods: Fish Are Friends Mod from Kawaiistacie.
This mod is an override, it adds new interactions to the aquarium/fishbowl including a minor breeding feature. Interactions are anonymous which means you’ll see your sims and NPC fully interacting with the fish. There is a chance that you will get mood let buffs from interacting with the fish. The animations used are borrowed from other interactions in the game currently since I am not an animator. There is a chance that your fish will have eggs. Interacting with the fish increases your chances and also having a high fishing skill level. The fish will be random so this breeding feature is not as detailed as it could be.