Dugesia tubqalis Harrath & Sluys, 2012

Harrath, Abdul Halim, Sluys, Ronald, Merzoug, Djemoi, Khebiza, Mohamed Yacoubi-, Alwasel, Saleh & Riutort, Marta, 2012, Freshwater planarians (Platyhelminthes, Tricladida) from the Palearctic section of the African continent: new records, with the description of a new species, Zootaxa 3182 (1), pp. 1-15 : 2-4

Dugesia tubqalis Harrath & Sluys , sp. nov.

Material examined

Holotype: ZMA V.Pl. 6905.1, Imlil and Taddert , Toubkal Mountains, Marrakech, Morocco, 23 December 2009, coll. A. H. Harrath, sagittal sections on 18 slides.

Paratypes: ZMA V.Pl. 6905.2, ibid., sagittal sections on 18 slides ; V.Pl. 6905.3, sagittal sections on 16 slides; V.Pl. 6905.4, horizontal sections on 6 slides; V.Pl. 6905.5, horizontal sections on 8 slides.

Other material: ZMA V Pl. 6906.1, Taddert , Toubkal Marrakech, Morocco, 23 December 2009, coll . A. H. Harrath , sagittal sections on 19 slides .

Etymology

The specific epithet is derived from the Berber name Tubqal for the highest peak in the Atlas Mountains (over 4000 m). It is located at approximately 60 km from Marrakesh city, in southern Morocco.

Habitat

Specimens were collected from two springs in the Toubkal Mountains. The first one, Imlil spring (31° 07’45.06’’ N, 7° 58’33.32’’E), is situated at an altitude of 1702 m. The second spring, Taddart (30° 59’56 16’’ N, 8° 27’64’’E), is situated in a very cold and snowy zone, at an altitude of 2164 m ( Fig.1 ). We did not observe any other macroinvertebrates associated with the triclads.

Diagnosis

Dugesia tubqalis is characterized by: an elongated penis and muscular penis bulb surrounded with two penial folds at its base, the dorsal one bigger than the ventral; an atrium divided by a kind of non-muscular ridge into a male and a common atrium; a terminal expansion of the ejaculatory duct just before it opens at the tip of the penis papilla.

Description

The largest specimen measured in life up to 20 mm in length and 3 mm in width. The dorsal surface is densely pigmented, while the ventral surface is paler, as pigmentation is less dense. Head of low triangular form with two eyes set in pigment free-patches. ( Fig. 2a ).

The pharynx is situated at the middle of the body. It measures approximately one-third of the total body length and shows the usual planariid arrangement of its musculature.

The numerous testes are situated dorsally, extending from anterior to the ovaries to almost the end of the tail. The two large vasa deferentia run ventrally, but after having entered the penis bulb they curve antero-dorsally and narrow before separately opening into the posterior section of the seminal vesicle. The latter opens via a short diaphragm into the proximal, funnel-shaped section of the ejaculatory duct. This broad ejaculatory duct runs a slightly ventrally displaced course through the penis papilla, opening terminally at its tip. Just before opening at the tip, the ejaculatory duct forms a terminal expansion. The ejaculatory duct is surrounded by a layer of circular muscle. The cone-shaped and slightly asymmetrical penis papilla is covered with a thin, nucleated epithelium that is underlain with a layer of circular muscle, followed by a thin layer of longitudinal fibres. The semispherical and muscular penis bulb consists of intermingled longitudinal and circular muscle fibres. There are two distinct penial folds, with the one dorsally to the penis being bigger than the ventral ( Figs.3a, b ).

The ovaries are of normal size and are situated ventrally, close to the brain. The oviducts arise from the postero-dorsal side of the ovaries and run ventrally above the ventral nerve cords to a level posterior to the copulatory apparatus. At this level the oviducts turn towards the dorsal side and open separately, but symmetrically, at the base of the bursal canal.

The large copulatory bursa is surrounded by a thin layer of longitudinal muscles. The bursal canal widens before communicating with the common atrium. The bursal canal is lined with a relatively thick, nucleated epithelium and is covered with a thin layer of longitudinal muscles, followed by a relatively thick layer of circular muscles.

Figures

FIGURE 1. Distributional records in Northern Africa of the species studied in this paper.

FIGURE 2. Cephalic ends of Dugesia tubqalis (a), Dugesia sicula (b), Schmidtea polychroa (c), Polycelis nigra (d), Polycelis felina (e). Scale bar: 1mm.

FIGURE 3. Dugesia tubqalis (Holotype, V. Pl. 6905.1): (a) microphotograph of the copulatory apparatus, (b) sagittal reconstruction of the copulatory apparatus.