Type locality: Iponcin Creek into Approuage River, French Guiana (Ref. 26282, 6868). Found in the rapids of the Arataye River during dry season (Ref. 27233). The Maroni variety could be a separate species (H. tapanahoniensis Boeseman, 1969) with the tip of its dorsal fin quite close to the adipose fin and the height of the caudal pedicle limited to less than 2.1 times the interdorsal distance. A second variety (H. nematopterus Isbrücker & Nijssen, 1984) present in the Oyapock has more teeth, a dorsal fin reaching the adipose fin, and the first ray of the dorsal fin being very long, folded, reaching the caudal fin (Ref. 35381).