heikoi, Moenkhausia Géry [J.] & Zarske [A.] 2004:30, Figs. 1-7 [aqua, Journal of Ichthyology and Aquatic Biology v. 9 (no. 1); ref. 28287] Rio Iriri, a left-hand tributary of the Rio Xingú well above Altamira, at edge of island between Rio Novo and Igarapé Grota, about 10 kilometers below mouth of River Novo, Para, Brazil, about 4°25'S, 53°40'W. Holotype: MZUP 83536. Paratypes: MHNG 2644.30 (1), MTD F 27909

"Moenkhausia heikoi seemed to prefer the shallow water from about 15-100 cm in depth." - Peter Persersen, Rio Xingu, 2018.