Growing fish and selling them for the most coins in Happy Aquarium is fun for millions but why should pay so many coins for fish eggs when you can add new baby fish to the tank the natural way? Mating is how most creatures reproduce in the real world and while your fish appreciate when you hit the Give Love button, sometimes they're looking to get love too.
To mate, there are a few conditions that you'll need to meet.
Of course, waiting for your fish to get to adulthood may take some time. Once an adult, make sure they're well fed, the tank is clean and make sure you have half the coins it usually costs to buy an egg from that fish (example: Auriga eggs normally cost 14 coins, so mating costs 7 coins). If you miss any of those conditions, you'll get the "Almost There!" screen until you figure out what condition's not being met. As you can see below, we had to wait for our male Auriga, Rascal, to mature enough to mate. Once ready, use the pointer to select either fish and click the Mate button.