Despite its extensive natural distribution S. lilith is uncommon in the ornamental trade, where it is sometimes referred to as ‘one-spotted demon fish’ or ‘one spot eartheater’.

It can be distinguished from other members of the genus by possessing a single dark blotch on the flank and a prominent ocellus at the caudal-fin base. Among the named species it is most similar to S. daemon, but that species possesses two blotches on the flank.

This species is also referred to as ‘South American puffer’, ‘SAP’, ‘Amazonian puffer’, ‘Peruvian puffer’, or ‘Brazilian puffer’ in the ornamental trade.

Within the genus Colomesus, C. asellus can be immediately identified by possessing a unique transverse row of dermal flaps across the chin which is absent in its congeners C. psittacus and C. tocantinensis.

Native to coastal river systems south of the Amazon delta in the states of Piauí, Maranhão, Pará, and Amapá, northeastern Brazil. It has been recorded from the rios Guamá (including tributaries such as the rio Ararandeua), Maracanã (rio Peixe-Boi), Morcego, Parnaíba, Piriá, Caeté, Turiaçu (rio Jamari), and Mearim (rio Pindaré).

Reports from French Guiana and western Brazil appear to represent cases of misidentification.