Exclamation Point Rasbora

Boraras urophthalmoides comes from slow, blackwater streams across Southeast Asia, particularly in Thailand and surrounding regions. It earns its common name from a dark lateral stripe that terminates in a bold, round spot at the tail base, giving the fish's body a literal exclamation point silhouette. At a maximum of around 2cm, it's one of the smallest schooling fish available in the hobby, and that tiny scale is part of what makes it so appealing in a well-planted nano setup.

Body coloration is a warm reddish-pink to coppery orange, with a secondary dark marking near the dorsal region that varies between individuals. Under good lighting in a dark-substrate, blackwater-style tank, they genuinely glow.

Water chemistry matters more than it does for many other nano fish. 5 range bring out their best color and keep immune stress low. Tap water treated with peat, Indian almond leaves, or similar will do a lot of the heavy lifting. They're not particularly demanding feeders, accepting small prepared foods like micro pellets and crushed flake, but they'll thrive with a regular rotation of live or frozen micro foods like baby brine shrimp, micro worms, and daphnia.

In terms of temperament, they're utterly harmless. A large school of these moving through a heavily planted foreground is one of those quietly mesmerizing tank experiences that photos don't fully capture.