Dugesia sigmoides, 2017

Stocchino, Giacinta Angela, Sluys, Ronald, Riutort, Marta, Solà, Eduard & Manconi, Renata, 2017, Freshwater planarian diversity (Platyhelminthes: Tricladida: Dugesiidae) in Madagascar: new species, cryptic species, with a redefinition of character states, Zoological Journal of the Linnean Society 181, pp. 727-756 : 741

DUGESIA SIGMOIDES STOCCHINO & SLUYS SP. NOV.

( FIGS 6–7, TABLE 1)

Material examined

Holotype: ZMA V.Pl. 7262.1, one set of sagittal sections on 13 slides, Central High Plateau , Eastern Slope , unnamed small water course (1–2 m wide), tributary of the Mandraka River in the upper Mangoro River hydrographic basin, Route 2 in the ‘ Peyrieras Reserve’ (18°55 ′ 55.040 ″ S, 47°57 ′ 0.993 ″ E) at Marozevo Village, Manjakandriana District, Madagascar, 15 September 2011, coll. R. Manconi.

Paratypes: CGAS Pla 9.1, ibid., sagittal sections on 16 slides ; ZMA V.Pl. 7262.2, ibid., sagittal sections on 8 slides

Etymology

The specific epithet is based on the Greek letter S, Sigma, and alludes to the S-shaped ejaculatory duct.

Diagnosis

Dugesia sigmoides is characterized by the presence of the following features: asymmetrical openings of the oviducts into the bursal canal; ectal reinforcement extending along the entire length of the bursal canal; hyperplasic ovaries; central S-shaped course of the ejaculatory duct; subterminal opening of the ejaculatory duct; elongated seminal vesicle; openings of the vasa deferentia at a position about halfway along the seminal vesicle; large diaphragm.