Is My Betta Fish Pregnant?

A common misconception exists regarding the reproductive process of betta fish. While some fish species are indeed viviparous (livebearers), bettas are oviparous (egg-layers). This distinction is crucial, as females develop eggs that are subsequently released and fertilized externally rather than carrying embryos internally until birth. In other words, a betta fish is never ‘pregnant’, but it might be full of eggs ready to lay.

Here’s the scoop on betta breeding:

• Betta Fish Eggs: Female bettas develop eggs, and their bellies may appear plump. This doesn’t mean they’re pregnant, just ready to spawn (release eggs) if a male is present. Eggs hatch in about 3 days. We have an article that talks more about the eggs and egg nests here.

• The Spawning Dance: If a male betta is in the tank, he’ll build a bubble nest and court the female. If she’s interested, she’ll release eggs, and the male will fertilize them and place them in the bubble nest.
• No Womb: Unlike livebearers (like guppies), bettas don’t carry fertilized eggs inside them. The eggs develop in the bubble nest until they hatch.

So, what if your betta looks plump and there’s no male around?

• Not All Puff is Pregnancy: Bettas can bloat due to overfeeding or constipation. Observe their behavior and droppings to rule these out. We have a guide on betta diseases and ailments which can help diagnose the issue.
• Egg Absorption: If there’s no male, the female will eventually reabsorb the eggs.

Want to learn more about betta breeding?

If you’re interested in breeding bettas, there’s a whole world to explore! Research proper tank setup, breeding techniques, and raising baby bettas (fry). I suggest getting a guidebook if your betta is laying eggs with a male around, because soon enough you might need some additional information.