Akysis portellus

<em>Akysis portellus</em> is a small freshwater catfish belonging to the family Akysidae, a lineage of diminutive torrent catfishes distributed across river systems of South and Southeast Asia. This species attains a maximum recorded length of approximately 3.43 cm, consistent with the generally miniaturised body plan typical of the genus <em>Akysis</em>. Akysidae are characterised by robust pectoral and dorsal fin spines, a roughened tuberculate skin texture, and a strongly depressed head and anterior body that facilitate a benthic lifestyle in high-gradient streams. <em>Akysis portellus</em> is thought to inhabit fast-flowing, well-oxygenated hill streams and river tributaries where it adheres to rocky and gravelly substrate in riffle and rapid zones. This rheophilic association helps the species exploit benthic food resources — primarily small aquatic invertebrates, periphyton, and fine organic detritus — while resisting displacement by current. Like most members of the genus, <em>Akysis portellus</em> is believed to be primarily nocturnal, increasing foraging activity after dark. Details of habitat and range for this species remain limited in the ichthyological literature. The taxonomy of the genus <em>Akysis</em> has been subject to ongoing revision as molecular and morphological analyses refine species boundaries. <em>Akysis portellus</em> has not been formally assessed for conservation status.