They form a single row around the anterior tip and after the first millimeters they become pluriserial, spreading to the dorsal surface and occupying about one third of the body width on either side.

[3] The dorsal eyes are surrounded by clear halos (areas devoid of pigmentation) which may be perceived as a set of small whitish dots under close inspection or under a stereo microscope.

The general color pattern of O. nungara is very similar to that of Obama marmorata, a species with which it lives in sympatry in some areas in southern Brazil.

Since 2008, a large land planarian has been found in several localities in Europe, including Guernsey, Great Britain, France, Spain, Italy[2][5] and, more recently, Belgium,[6] the Netherlands,[7] Slovakia.

[14] On the basis of a molecular analysis, the study also concluded that the population which has invaded several countries in Europe came from Argentina, not Brazil.

[14] Obama nungara was recorded from the French island of La Réunion, off the African coast, in a paper published in 2022.

[15] In southern Brazil, O. nungara (identified as O. marmorata) was reported to feed on the invasive land planarian Endeavouria septemlineata.

[3][10][14] More precisely, a 2022 study based on metabarcoding of the gut contents of specimens of O. nungara collected in France showed that the flatworm consumes a variety of earthworm species.