Kubotai Rasbora (Microdevario kubotai)

The Kubotai Rasbora (Microdevario kubotai) is one of the most striking nano fish you can put in a planted tank. Barely three quarters of an inch long, it wears a band of electric lime green that lights up like neon paint the moment it crosses a beam of light, and a proper school of them moving through stem plants looks like a handful of sparks drifting downstream. Peaceful, active, and endlessly social, it is an intermediate level fish only because it is tiny and wants a mature, stable tank, not because it is difficult. Browse the rest of our freshwater livestock and supplies to build the rest of the school's world.

Care Guide

• Buy them in numbers. Eight is the floor, twelve or more is where they actually behave like themselves. In small groups they hide, stay pale, and eat poorly. In a real school they hold the open water and the green stripe intensifies.
• Tank size: 10 gallons for a starter school, 20 gallons long or larger if you want a big shoal with room to cruise. Length matters more than height.
• Mature tank required. These are micropredators with almost no reserves. Add them to an established, cycled tank with stable parameters, never to a tank that finished cycling last week.
• Water parameters: 72 to 79°F, pH 6.0 to 7.5, GH 2 to 12. Soft to moderately hard, slightly acidic to neutral is ideal. Consistency beats chasing exact numbers.
• Aquascape: heavily planted with open swimming lanes down the middle. Fine leaved stems, mosses, and floating plants that soften the light will bring them out into the open faster than a bare tank ever will.
• Feeding: omnivorous micropredator with a very small mouth. Crushed flake, micro pellets, nano slow-sinking pellets, and frozen baby brine shrimp, daphnia, or cyclops. Feed small amounts twice a day rather than one large meal.
• Flow and filtration: gentle. A sponge filter or a baffled hang-on-back is perfect. They come from clear forest streams, so they appreciate a little current but should never be pinned against the glass by it.
• Lid strongly recommended. Startled nano danionins skip across the surface, and a fish this small can slip through a surprisingly narrow gap.

Specifications

Compatibility

Kubotai Rasbora are completely peaceful and will not bother anything, which also means they need tank mates that will not bother them. Keep them with other small, calm species: Celestial Pearl Danio, Micro Tiger Rasbora, Ember Tetra, Pygmy Cory, and Otocinclus all make excellent company. Invertebrates are a natural fit too: Cherry Shrimp are safe with adults, and nerite snails handle algae without competing for food.

Avoid anything large, fast, or nippy. Full grown barbs, larger gouramis, angelfish, and most cichlids will either eat them outright or stress them into hiding permanently. Puffers and fin nippers are a hard no.

Recommended Foods & Supplies

• Hikari Micro Pellets sized for nano mouths
• Xtreme Nano Slow-Sinking Pellets staple for micro fish
• SFBB Baby Brine Shrimp frozen conditioning food
• Seachem Prime water conditioner for every water change
• Fritz Catappa Leaves for gentle tannins and a softer, more natural look
• Live plants to give the school cover and confidence

FAQ

Is this the same fish as a Green Neon Tetra?
No. Green Neon Tetra is Paracheirodon simulans, a South American characin. The Kubotai Rasbora is an Asian danionin from Thailand and Myanmar. They look superficially similar in a photo and get confused constantly, but they are unrelated fish with different care needs.

Mine look washed out and pale. What is wrong?
Almost always the group is too small or the tank is too bare. Bump the school up toward twelve, add plants and floating cover to break up the light, and give them a week to settle. The green comes back once they feel safe enough to stay in the open.

Are they safe with shrimp?
Yes with adult shrimp. Their mouths are far too small to threaten a grown Neocaridina. Newly hatched shrimplets in an open tank may get picked at, so add moss and cover if you want a colony to breed alongside them.

Will they breed in my tank?
They are egg scatterers and will spawn readily in soft, well planted water, but the parents and tank mates eat the eggs. You will occasionally find a survivor hiding in dense moss. Raising a real batch takes a separate grow-out tank and infusoria sized food.