Synaptolaemus is a small genus of headstander characins, fish named for their habit of swimming at a steep head-down angle as they graze algae and biofilm from submerged surfaces. The atlas's two species, Synaptolaemus cingulatus (the bristlenose headstander) and S. latofasciatus (the red-banded headstander), are native to Amazon and Orinoco basin drainages spanning Brazil, Colombia, Venezuela, and Guyana, reaching roughly 3.5–4.5 in. Their slender, laterally compressed bodies and small fringed snouts suit them to picking algae and detritus from wood and rock in slow to moderate current.
Both species turn up only occasionally in the aquarium hobby, generally through specialist importers rather than mainstream retail, and detailed captive-care information remains limited. Where they are kept, headstanders of this kind are valued for their distinctive oblique swimming posture and grazing behavior rather than for bright coloration. Synaptolaemus latofasciatus is assessed as Least Concern, while S. cingulatus has not yet been formally evaluated, so the wider conservation picture for the genus is still being filled in.