Do All Fish Lay Eggs? Do all fish lay eggs? Well, here's a fun fact for you. Not all fish are egg-layers! There's a fascinating group of fish known as live bearers. These aquatic marvels give live birth, just like mammals. Some of the most popular freshwater fish, like swordtails, mollies, and platies, belong to this group. Keeping these fish is a breeze. Simply put the males and females together in an aquarium, and voila! In a few weeks, you'll have a tank teeming with tiny fish. Isn't nature a