Max Size: 4cm

Volcano Rasbora (Rasbora vulcanus)

Volcano Rasboras are active, peaceful, attractive and easy to keep making them a great addition to a community aquarium and the hobby. However, Volcano Rasboras are schooling species in nature; therefore, it would be best if you kept them in groups of at least eight individuals. Maintaining these fish in more significant numbers will not only make your fish less nervous but will result in a more natural-looking display. Males will also reveal their best colours as they compete for female attention.

Volcano Rasboras have no particular demands when it comes to water chemistry, so you can combine them with most of the popular fish in the hobby. These can include other small Cyprinids such as Barbs as well as Tetras, Rainbowfish, Livebearers, Catfish and Loaches.

Choosing decor is not crucial; however, these Rasboras tend to show better colouration when maintained in a heavily-planted set-up with a dark substrate. The addition of some driftwood roots or branches and some floating plants to help diffuse the aquarium's light also seems to be appreciated and also adds a more natural feel.

You should not add these Rasboras to a biologically immature aquarium as they can be susceptible to changes in water chemistry. Also, it is essential that your aquarium has a tight-fitting lid or a significantly lowered waterline as these fish are accomplished jumpers if startled or excited.

Volcano Rasboras have a dark lateral line down the entire length of the body and pinkish-red coloured fins, and there is a reticular scale pattern on the sides similar to that of Barbs. Males have a reddish-orange hue over their bodies that get more intense when spawning, and mature females have a pale golden hue over their body.

Quick Facts
Scientific NameRasbora vulcanus
Other NamesNone
Aquarium LevelBottom - Middle
DifficultyBeginner - Intermediate
Best kept asGroups 8+
Lifespan4 - 8 years
Water Parameters
Water TypeFreshwater
PH6.5 - 7.5
GH2 - 15
73 - 79℉
22.8 - 26.1℃

Photos of the Volcano Rasbora

Volcano Rasbora

Natural Habitat

Currently, there is not much information on the origins of Volcano Rasboras; however, they are believed to be endemic to the Batang River in northern West Sumatra in Indonesia in Southeast Asia, where they inhabit clear, moderately flowing streams.

What to feed the Volcano Rasbora

Volcano Rasboras are primarily micro predators in nature, feeding on tiny invertebrates such as insect larvae. However, these fish are unfussy in the aquarium and will accept most high-quality dry foods. However, you should also feed them a varied diet that includes live, frozen or freeze-dried foods of suitable size.

How to sex the Volcano Rasbora

It is relatively straightforward to differentiate between the males and female Volcano Rasboras. Males are usually a little slimmer, slightly smaller and more vibrantly coloured than females. In contrast, mature females are generally heavier-bodied, a little larger and appear a lot duller than males.

How to breed the Volcano Rasbora

Volcano Rasboras are egg-scattering, continuous spawners that show no parental care. However, when these fish are well-fed, they will usually spawn, and small numbers of fry may start to appear and may survive in a densely planted community aquarium.

If you would like to maximize the yield of fry, you will require a separate breeding tank. This tank should be relatively shallow and dimly lit and contain plenty of fine-leaved plants. Alternatively, you can cover the tank's base with either mesh, marbles or pebbles so that the non-adhesive eggs can fall through and the adults cannot reach them.

The water in the breeding tank should be slightly acidic and filtered with a mature air-powered sponge filter. Also, it would help if you raised the temperature slightly compared to their usual aquarium. Finally, you can induce spawning by topping up the tank with small amounts of cold water to resemble rain and conditioning them with plenty of live and frozen foods.

Once spawning is complete, you should remove the adults as they will consume the eggs and fry if given the opportunity. The Incubation period is temperature-dependent, but usually, the eggs will hatch within 24 to 48 hours later. One to two days after that, the fry will start to swim freely.

It would be best if you initially fed the newly hatched fry with infusoria or commercial liquid fry food, then once they are big enough, you can provide them with microworms and baby brine shrimp.

Other Rasboras of interest

Black Line Rasbora(Rasbora borapetensis)
Chilli Rasbora(Boraras Brigittae)
Clown Rasbora(Rasbora kalochroma)
Dwarf Rasbora(Boraras maculatus)
Emerald Eye Rasbora(Brevibora dorsiocellata)
Exclamation Point Rasbora(Boraras urophthalmoides)
View all Rasboras
Date Added: 08/02/2022 13:10:33 - Updated: 08/02/2022 13:31:53