Kingdom Animalia Suborder Continenticola Subfamily Geoplaninae Phylum Platyhelminthes Order Tricladida | Class Rhabditophora Family Geoplanidae Scientific name Obama Rank Genus | |
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Similar Obama nungara, Geoplaninae, Paraba, Geoplanidae, Tricladida | ||
Obama is a genus of land planarians from South America. It contains several species adapted to human-disturbed environments, including the only invasive land planarian native to the Neotropical ecozone, Obama nungara, which has been accidentally introduced in Europe.
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Description
The genus Obama is characterized by having a leaf-shaped body. Most species are about 10 centimetres (3.9 in) long, but some may reach over 20 centimetres (7.9 in). The hundreds of eyes distributed along the body are of two types: monolobulated, which are simple and circular, and trilobulated, which have three lobes.
The copulatory apparatus of Obama has a protrusible penis occupying the entire male atrium or most of it. Morphologically the genus can be divided in two subgroups depending on the shape of the penis papilla, which may be symmetrical or asymmetrical. The group with an asymmetrical penis papilla includes 10 species (O. anthropophilla, O. carbayoi, O. carrierei, O. decidualis, O. josefi, O. ladislavii, O. marmorata, O. nungara, O. otavioi and O. ruiva) and seems to form a monophyletic clade within Obama. On the other hand, the group with a symmetrical penis papilla is paraphyletic, indicating that this is the ancestral state within the genus.
Etymology
The name Obama is formed by a composition of the Tupi words oba (leaf) and ma (animal), being a reference to the body shape of species in this genus.
Species
There are 38 species assigned to the genus Obama:
Phylogeny
The genus Obama was erected after a study of molecular phylogeny with the subfamily Geoplaninae revealed that the genus Geoplana, originally containing more than a hundred species, was polyphyletic. One of the monophyletic clades revealed by the study was separate from Geoplana as the new genus Obama. All species within the new genus share a similar morphology, including the leaf-shaped body, the presence of a permanent penis papilla, ovovitelline ducts entering the female atrium dorsally and dorsal eyes of two types: mono- and trilobulated.
The sister-group of Obama seems to be the genus Cratera, which has a very similar appearance but lacks trilobulated eyes.
The following phylogenetic tree shows the relationship of several species of Obama after several molecular studies: