Author: (Eigenmann & Eigenmann, 1888)
Remark: Species-level distinctiveness of Tocantins and Amazonas <i>Megalodoras</i> not investigated.
Comments: Occurs in small groups and occasionally forms schools.  Inhabits rivers.  Is mainly diurnal.  Feeds on the fruits of <i>Licania longipetala</i> and <i>Astrocaryum jauary</i>.  Also feeds on pulmonate snails (Ref. 9086).