A least rasbora (Thai: ปลาซิวหนู) or <i>Boraras urophthalmoides</i> in an aquarium. This wild-caught specimen is still recovering from the catch and is not in the prime condition. It displays a non-breeding color pattern, which makes it difficult to identify the sex. Picture taken by myself.
<a href="//commons.wikimedia.org/wiki/User:Melanochromis" title="User:Melanochromis">Melanochromis</a>
<span class="int-own-work" lang="en">Own work</span>