Parosphromenus, the licorice gouramis, is a genus of tiny labyrinth fish in the gourami family Osphronemidae, restricted to the blackwater peat-swamp forests of Sundaland — the atlas's records span Indonesia, Malaysia, Brunei, and Thailand. These are among the smallest anabantoids kept in the hobby, with the atlas's 23 species running from roughly 0.5–2 in, and they are built for a very specific habitat: soft, acidic, tannin-stained water low in dissolved minerals, shaded by dense swamp-forest canopy. Unlike the bubble-nesting gouramis most aquarists know, Parosphromenus species are cave or crevice spawners, with the male guarding a small clutch of eggs in a sheltered site rather than a surface nest.
In the hobby Parosphromenus is a specialist's genus — prized by dedicated blackwater and labyrinth-fish keepers for the males' intense, jewel-like breeding coloration, but demanding on water chemistry, needing very soft, acidic, tannin-rich conditions and live or high-quality foods rather than tolerating typical community-tank parameters. The genus is also one of the most conservation-critical in the atlas: the peat-swamp forest that is its only habitat has been drained and cleared at large scale for oil-palm agriculture, and the atlas's IUCN tally shows the great majority of assessed species rated Critically Endangered, Endangered, or Vulnerable. With 22 of the atlas's 23 species flagged for CARES conservation priority, hobbyist breeding programs are widely seen as a meaningful part of the genus's survival prospects.