I do agree that when it comes to keeping or having pets at home, we generally prefer cats and dogs, mainly because they are interactive and prove to be excellent companions. However, raising fish can be an altogether different experience, as they are elegant and quiet pets. Fish, being aquatic, prefer living for themselves and thus, don't require much attention and care. Though this sounds easier in comparison to other pets, you need to give them good quality fish food and create an environment similar to their natural habitat; only then will they grow into wonderful species that they are. Now, if you have killifish or are planning to raise them, then you ought to know the breeding techniques, and the dos and don'ts associated with them. Killifish Raising To start off, killifish are small elongated fish that come in varied attractive colors, which make them popular pets; despite their aggressive behavior. If you happen to check, there are around 1270 species of this aquarium fish that are flexible enough to thrive in any type of water habitat. Habitat As I stated, killifish adjust to any type of water; right from large water bodies, like oceans and seas, to small rivers and lakes. They thrive in mud puddles and standstill water with equal ease. Owing to this adaptability, they are found in almost all parts of the world; except for Australia and extremely colder regions of the Arctic and Antarctica. For breeding these fish at home, you need to first buy a spacious fish tank. For their optimum growth, you need to pay attention to the chemistry of water you will keep them in. Too alkaline water is not tolerated by these fish. The optimum pH value of the water should be in the range of 6 and 7. Behavior Killifish dwell in 3 parts; some prefer living at the bottom, some prefer middle, and some dwell at the surface of the water. Similarly, when it comes to breeding, some killifish prefer spawning eggs at the bottom, preferably on sand, while others lay eggs in the cracks of rocks or generally in hidden areas (within mosses). If you study their behavior, you will find that they are not highly active and generally maintain a low profile. However, as I mentioned, they are considered highly aggressive―especially the males―and can cause harm to other species dwelling with them. This usually happens during territorial fights. So, you need to choose good tank mates for them. If you are raising killifish in an aquarium, you will also need to buy some artificial aquatic plants, mosses, wood, or rocks. Food You need to feed them hygienic and good quality fish food that would keep them healthy and free of any freshwater fish diseases. They love to feed on insects, mosquitoes, and worms, which are found in their natural habitat. Their diet varies from species to species though; wherein some like to eat water algae and aquatic plants, while some feed on other aquatic fish as well. You also have the option of buying killifish food available in the market. While breeding killifish species, you need to pay special attention to their eggs and the resultant fry, mainly because killifish themselves do not take care of them. You have to remove the eggs from the tank and grow them in a separate tank. The fry develop in a span of 14 days and mainly feed on infusoria, brine shrimp, or microworms. If you are interested in owning the most common and popular killifish in the market, then go for Golden Wonder killifish, since these are easiest to spawn and breed.