Pseudocheirodon is a small genus of characins - true tetras - restricted to Central America, specifically Costa Rica and Panama, making it one of the northernmost tetra genera in the New World tropics. The genus's 2 species in the atlas are modest in size, 1.5–2 in, with the slim, laterally compressed body and forked tail typical of small schooling characins, likely feeding as omnivorous micro-predators of small invertebrates and organic matter in clear to tea-stained forest streams.
Arnold's tetra (Pseudocheirodon arnoldi) is the better known of the two species, occasionally available in specialty tetra collections, while P. terrabae is documented mainly in ichthyological surveys rather than hobby literature; detailed care information for the genus is sparse. The conservation picture is mixed - one species carries a Least Concern rating while the other is assessed Vulnerable - a reminder that Central America's small, range-restricted stream fish can face real habitat pressure even within a compact geographic range.