The Moenkhausia forestii lives in the benthopelagic, freshwater environment.
species Moenkhausia forestii, and distinguish it from congeners in having a reticulate body and a conspicuous dark blotch on the caudal peduncle extending to the base of caudal-fin rays preceded by a lighter area, lateral line incomplete, 23–26 lateral-line scales, 5 scale rows above the lateral line, More
Moenkhausia forestii is readly distinguished from all congeners, except M. oligolepis, M. sanctaefilomenae, M. pyrophthalma, and M. More