Neon tetras are brightly colored little fish that get their name from the metallic blue stripe on their sides. They live in schools and will breed in captivity, but they can be pretty fussy about waiting for just the right conditions, and they may decide not to spawn at all.
Neon tetras don’t mate in the same way that some other fish, such as guppies and mollies, do. When neons are ready to spawn, the female will scatter her eggs and the male will immediately fertilize them. They go through this process several times during spawning, scattering the eggs on the floor of the tank. Once they’re done, you should remove your adults, since they may eat the eggs or babies.
Neons do best when you separate the breeding pair. Telling the males from the females so that you know which one to remove can be a bit difficult, and it takes a practiced eye to get it right. In general, you won’t find any obvious sex-related characteristics, but the female typically looks fuller and rounder through the body than the male does. If you look down at your fish from the top of the tank, the girls are noticeably wider than the boys.
A couple of inches of rock on the bottom of the tank makes a good landing place for the eggs, and a lid will keep the parents from jumping out during some of their more passionate moments. They don’t need plants, though if you have some in the tank the eggs may land on the leaves and stick there. A sponge filter in one corner is a safe way to keep the water clean for the babies.
Before they’ll spawn, neons have to have just the right conditions. They like soft water with an ideal dH indicator – the measure of hardness -- of about 1 to 2, which you can measure with a test kit from the pet store, if you wish. Keep the pH around 5 or 6, and maintain a water temperature of 74 degrees Fahrenheit or less, but don’t let it drop below about 70. Changing half the water often encourages spawning and is a good way to get things started if your fish don’t seem too motivated.
A change in the light triggers spawning, since these fish are programmed by nature to lay their eggs the first thing in the morning. Keep them in the dark for 12 hours or so, then allow a small amount of light into the tank. No matter what time of day it is, they’ll react like it’s daybreak and the male will begin to dance around his love in preparation for the big event. Depending on how bright it is, the fish could take anywhere from about 15 to 60 minutes to get underway.
- Aquatic Community: Neon Tetra
- Tetras and Barbs: The Complete Guide to the Successful Care and Breeding; Randy Carey (PG 84, 108-113)