Obama nungara

Fernando Carbayo, Marta Álvarez-Presas, Hugh D. Jones & Marta Riutort, 2016, The true identity of Obama (Platyhelminthes: Geoplanidae) flatworm spreading across Europe, Zoological Journal of the Linnean Society 177, pp. 5-28 : 25

OBAMA NUNGARA IS A NEW SPECIES

The new species shows morphological features of the genus and in our molecular trees it fits within a clade exclusively composed of species of Obama ( Obama sp. 6 in Carbayo et al., 2013, and Fig. 1). Nevertheless, a diagnostic feature of the genus, multiple sensory pit rows opening at each side of the body, is absent in this species, as in O. marmorata . In this respect, the genus should be taxonomically revised.

The new species should be compared with species of Pseudogeoplana Ogren & Kawakatsu, 1990 and with other species of Obama . The former genus includes species of Geoplaninae considered species inquirendae and nomina dubia because of insufficient morphological information, mainly internal. However, none of the species in Pseudogeoplana has a body colour pattern resembling the new species.

Among the 36 species of Obama , only O. marmorata compares well with the new species in having the dorsum patterned with marbled, short longitudinal dark striae. Furthermore, at first sight, the two species are very similar to each other in their general external appearance and in their internal features. To add complexity to the problem, O. marmorata and O. nungara sp. nov. may be syntopic and at the time of sampling we suspected the slight differences in the colour pattern of the dorsum would be due to intraspecific variation. Nevertheless, O. nungara differs from O. marmorata in the following respects:

(6) the dorsal insertion of the penis is anterior to the level of the gonopore, not posterior as in O. marmorata , thus the base of the penis is narrower and more anterior than in O. marmorata ;

(7) the glands producing pinkish (bluish is some stains) granules present in the stroma of the penis run in conspicuous bundles as they approach the subapical height of the penis to discharge their content in distinct patches, whereas in O. marmorata the penis glands run in discrete bundles discharging the secretion evenly through the penis epithelium;

(8) the muscle fibres in the stroma of the penis are more numerous and most of them are arranged in bundles, whereas in O. marmorata they are scarcer and packed in less apparent bundles;

(9) the male atrium possesses a kind of large sheathlike fold on the right side running from the ventral anterior side of the atrium to nearly the dorsal level to the gonopore, thus separating the male from the female atrium, whereas the male atrium of O. marmorata is not folded and not separat- ed from the female one;

(10) the very numerous glands discharging their cyanophilic granules into the male atrium pierce an annular-shaped surface of its lining epithelium, whereas in O. marmorata the surface pierced by this type of gland does not exist dorsally, thus resulting in a U-shaped surface.

Moreover, our molecular species delimitation analysis suggests strongly that O. marmorata and O. nungara are different species ( Fig. 2; Supplementary material Fig. S1B). It also gives statistical support to the individuals of Brazil and the individuals from Europe and Argentina as belonging to the same species, although they are genetically quite differentiated. This is probably because the animals introduced to other countries originated from a different region of Brazil than the one analysed here.