Rasboras: Livebearers or Egg Layers? Answered

One question that often comes up with rasboras is whether they are livebearers or egg layers.

The answer is that rasboras are egg layers. Unlike livebearers such as guppies, platies, and mollies that give birth to free-swimming fry, rasboras scatter eggs externally throughout the tank.

The eggs are usually a milky white color, which allows them to blend into the substrate and helps protect them from being eaten.

Experience of Breeding Most Rasboras

While livebearers can be prolific breeders, breeding most species of rasboras can be a bit more challenging.

Providing good water quality, abundant live foods, soft and acidic water, and spawning aids will help induce spawning activity.

Java moss, coconut fiber mats, marbles, or specialty breeding mops give the fish places to scatter eggs and provide protection.

Using an air-powered sponge filter with an adjustable flow rate allows eggs to get gently caught on the surface, keeping them safe from predation.

Even with optimal conditions, getting many rasbora species to spawn can still take some patience and luck.

Some species, like galaxy, chili, and phoenix rasboras, tend to be easier, while others, like harlequin rasboras, can be more stubborn.

However, the parents do not care for the fry once they spawn, and the eggs hatch in one to two days.

So, moving the eggs/fry to a separate rearing tank is crucial to increase survival rates.

The Exception: Harlequin Rasboras

While most rasboras scatter eggs haphazardly around the tank, harlequins are unique in that the female lays eggs on the underside of a leaf.

This allows the male to follow and externally fertilize them in one location instead of chasing eggs dropped randomly on the tank bottom.

Once hatched, harlequin fry can even survive slightly better than other rasboras due to initially staying at the site of hatching instead of having eggs strewn across the tank.

But they will still require either dense plants or removal to a fry-only tank to reach adulthood.

Final Thoughts

Rasboras are vibrant and active fishes that lend color and energy to community freshwater aquariums.

While livebearers give birth to ready-to-swim fry, rasboras are egg-scattering species that spawn adhesive eggs fertilized externally by the male.

Providing good water quality, live foods, and spawning sites can help induce breeding activity, but raising the vulnerable fry is often the biggest challenge.