Schmidtea mediterranea phylogeography: an old species surviving on a few Mediterranean islands?

Schmidtea mediterranea (Platyhelminthes, Tricladida, Continenticola) is found in scattered localities on a few islands and in coastal areas of the western Mediterranean. Although S. mediterranea is the object of many regeneration studies, little is known about its evolutionary history. Its present distribution has been proposed to stem from the fragmentation and migration of the Corsica-Sardinia microplate during the formation of the western Mediterranean basin, which implies an ancient origin for the species. To test this hypothesis, we obtained a large number of samples from across its distribution area. Using known and new molecular markers and, for the first time in planarians, a molecular clock, we analysed the genetic variability and demographic parameters within the species and between its sexual and asexual populations to estimate when they diverged. Results: A total of 2 kb from three markers (COI, CYB and a nuclear intron N13) was amplified from ~200 specimens. Molecular data clustered the studied populations into three groups that correspond to the west, central and southeastern geographical locations of the current distribution of S. mediterranea. Mitochondrial genes show low haplotype and nucleotide diversity within populations but demonstrate higher values when all individuals are considered. The nuclear marker shows higher values of genetic diversity than the mitochondrial genes at the population level, but asexual populations present lower variability than the sexual ones. Neutrality tests are significant for some populations. Phylogenetic and dating analyses show the three groups to be monophyletic, with the west group being the basal group. The time when the diversification of the species occurred is between ~20 and ~4 mya, although the asexual nature of the western populations could have affected the dating analyses. Conclusions: S. mediterranea is an old species that is sparsely distributed in a harsh habitat, which is probably the consequence of the migration of the Corsica-Sardinia block. This species probably adapted to temperate climates in the middle of a changing Mediterranean climate that eventually became dry and hot. These data also suggest that in the mainland localities of Europe and Africa, sexual individuals of S. mediterranea are being replaced by asexual individuals that are either conspecific or are from other species that are better adapted to the Mediterranean climate

<i>Schmidtea mediterranea</i> phylogeography: an old species surviving on a few Mediterranean islands?

Background: Schmidtea mediterranea (Platyhelminthes, Tricladida, Continenticola) is found in scattered localities on a few islands and in coastal areas of the western Mediterranean. Although S. mediterranea is the object of many regeneration studies, little is known about its evolutionary history. Its present distribution has been proposed to stem from the fragmentation and migration of the Corsica-Sardinia microplate during the formation of the western Mediterranean basin, which implies an ancient origin for the species. To test this hypothesis, we obtained a large number of samples from across its distribution area. Using known and new molecular markers and, for the first time in planarians, a molecular clock, we analysed the genetic variability and demographic parameters within the species and between its sexual and asexual populations to estimate when they diverged. Results: A total of 2 kb from three markers (COI, CYB and a nuclear intron N13) was amplified from ~200 specimens. Molecular data clustered the studied populations into three groups that correspond to the west, central and southeastern geographical locations of the current distribution of S. mediterranea. Mitochondrial genes show low haplotype and nucleotide diversity within populations but demonstrate higher values when all individuals are considered. The nuclear marker shows higher values of genetic diversity than the mitochondrial genes at the population level, but asexual populations present lower variability than the sexual ones. Neutrality tests are significant for some populations. Phylogenetic and dating analyses show the three groups to be monophyletic, with the west group being the basal group. The time when the diversification of the species occurred is between ~20 and ~4 mya, although the asexual nature of the western populations could have affected the dating analyses. Conclusions: S. mediterranea is an old species that is sparsely distributed in a harsh habitat, which is probably the consequence of the migration of the Corsica-Sardinia block. This species probably adapted to temperate climates in the middle of a changing Mediterranean climate that eventually became dry and hot. These data also suggest that in the mainland localities of Europe and Africa, sexual individuals of S. mediterranea are being replaced by asexual individuals that are either conspecific or are from other species that are better adapted to the Mediterranean climate

Polycelis nigra

Polycelis nigra (Müller, 1774) Material examined ZMA V. Pl. 6909.1, Oued El Akarit located in the governorate of Gabes, Tunisia, 5 March 2010, coll. A. H. Harrath, sagittal sections on 10 slides; V. Pl. 6909.2, ibid., sagittal sections on 9 slides; V. Pl. 6909.3, ibid., horizontal sections on 6 slides; V. Pl. 6909.4, ibid.,sagittal sections on 12 slidesPublished as part of 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, pp. 1-15 in Zootaxa 3182 (1) on pages 10-11, DOI: 10.11646/zootaxa.3182.1.1, http://zenodo.org/record/524794

Dugesia sicula Lepori 1948

Dugesia sicula Lepori, 1948 Material examined ZMA V. Pl. 6907.1, Ain Mastour spring, Ousletia, Tunisia, (35° 52’ 22.40’’N 9° 37’36.41’’W) March 2009, coll. A. H. Harrath, sagittal sections on 11 slides; V. Pl. 6907.2, ibid., sagittal sections on 13 slides; V. Pl. 6907.3, horizontal sections on 10 slides. ZMA V.Pl. 6908.1, Oued Dhimine, Oum El Bouaghi, Algeria (36°01' 09.89" N 7°14' 38.75" W), coll. D. Merzoug, sagittal sections on 10 slides, V.Pl. 6908.2, ibid., sagittal sections on 8 slides.Published as part of 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, pp. 1-15 in Zootaxa 3182 (1) on page 6, DOI: 10.11646/zootaxa.3182.1.1, http://zenodo.org/record/524794

Polycelis felina

Polycelis felina (Dalyell, 1814) Material examined ZMA V. Pl. 6912.1, Ain Soltane spring, Imouzer-Kandar, Fes city, Morocco, 28 December 2009, coll. A. H. Harrath & K. Abdessalem, sagittal sections on 12 slides; V. Pl. 6912.2, ibid., horizontal sections on 18 slides; V. Pl. 6912.3, ibid., sagittal sections on 16 slides; V. Pl. 6912.4, ibid., sagittal sections on 18 slides; V. Pl. 6912.5, ibid., horizontal sections on 9 slides ZMA V. Pl. 6913.1, Ghazi spring, Aggar river, Safrou, Fes city, Morocco, 27 December 2009, coll. A. H. Harrath & K. Abdessalem, sagittal sections on 15 slides; V. Pl. 6913.2, ibid., sagittal sections on 8 slides; V. Pl. 6913.3, ibid., horizontal sections on 10 slides; V. Pl. 6913.4, ibid., sagittal sections on 10 slides. ZMA V.Pl. 6914.1, Taddirt, Toubkal- Marrakech, sagittal sections on 10 slides; V.Pl. 6914.2, ibid., sagittal sections on 9 slides; V.Pl. 6914.3, ibid., horizontal sections on 7 slides.Published as part of 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, pp. 1-15 in Zootaxa 3182 (1) on pages 12-13, DOI: 10.11646/zootaxa.3182.1.1, http://zenodo.org/record/524794

Schmidtea polychroa

Schmidtea polychroa (Schmidt, 1861) Material examined ZMA V. Pl. 6910.1, Arrafraf spring, Oum El Bouaghi city, Algeria, 05 February 2010, coll. A. H. Harrath, Djemoi Merzoug, sagittal sections on 21 slides; V. Pl. 6910.2, ibid., sagittal sections on 15 slides; V. Pl. 6910.3, ibid., horizontal sections on 8 slides; V. Pl. 6910.4, ibid., horizontal sections on 12 slides. ZMA V.Pl. 6911.1, Ain El Ajmi spring, Dahmani town, Tunisia, sagittal sections on 15 slides; V.Pl. 6911.2, ibid., sagittal sections on 14 slides; V.Pl. 6911.3, ibid., horizontal sections on 8 slides.Published as part of 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, pp. 1-15 in Zootaxa 3182 (1) on page 9, DOI: 10.11646/zootaxa.3182.1.1, http://zenodo.org/record/524794

Dugesia tubqalis Harrath & Sluys 2012, sp. nov.

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.Published as part of 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, pp. 1-15 in Zootaxa 3182 (1) on page 2, DOI: 10.11646/zootaxa.3182.1.1, http://zenodo.org/record/524794

Erpobdella testacea Savigny 1820

Erpobdella testacea (Savigny, 1820) Material examined. 325 specimens collected in: Elkhirba dam, Bizerte (37 ° 16 ' 354 ” N, 10 °09' 552 ” E), Port Prince dam, Cap Bon, Korbus (36 ° 51 ' 162 ’’ N, 10 ° 39 ' 404 ’’ E), Lebna dam (36 ° 44 ' 326 '' N, 10 ° 55 ' 255 '' E) and Marsh in Sejnen, Bizerte (37 °03’ N, 09° 13 ’ E). Description of examined specimens. The length of narcotized and preserved specimens can reach 40 mm; the width at mid-body region is up to 3 mm. The anterior sucker is longitudinally elliptical and the posterior sucker is circular. The dorsal surface of the living specimens is reddish brown in colour with minuscule darker specks situated dorsally (Fig. 3 a). The ventral surface is brighter than the dorsal (Fig. 3 b). The mid-body segment consists of five equally long annuli. Pharyngeal stylets are absent. The head has four pairs of eyes. In the majority of examined specimens the gonopores are separated by 4 annuli with the occasional occurrence of variation in their position. In fact it may reach in some specimens 4.75 annuli. The male reproductive system consists of numerous and globular testes that form voluminous and grape-like testisacs present on each side of the nerve cord and reach close to the posterior sucker. The vasa deferentia are about 7 ns long and they run from XII to XIX ganglia. They are located on the latero-ventral sides and connected to the atrium with the two ejaculatory ducts. The latter forms a loop, which is located in front of ganglia XI. The wide male atrium is 0.5 neurosomite (ns) in length and is located almost half way between the ganglia XI and XII. The atrium is small and the cornua are greatly expanded forming obtuse angle between them. They bend towards each other rather than to the ventral side. The bursa is relatively big (Fig. 4 a, b). The female reproductive system consists of two symmetric, U-shaped ovisacs situated on either side of the nerve cord. The ovisacs begin two-third of the way between the ganglia XII and XIII and end half way between the ganglia XV and XVI. They are connected to the pocket by oviducts. Ecology and distribution. The occurrence of E. testacea in Tunisia is restricted to lowland stagnant waters (50–65 m ASL). To date this species had been recorded from three reservoirs in the north of the country and from a small marsh. In the Lebna dam E. testacea is present in a large number all year round. Erpobdella testacea is a Palearctic species. In the Mediterranean region it is present in northern Italy and Greece (Nesemann 1997) and northern Tunisia (Ben Ahmed et al. 2008). It was recorded in Croatia, Montenegro, Bosnia and Herzegovina (Sket 1968). Remarks. While our specimens show a variation in the distance between gonopores which may reach 4.3–4.7, Agapow and Bielecki (1992) found a constant distance of 4 annuli between gonopores in the specimens studied in Poland. In contrast, Manoleli (1972) mentioned that in the majority of specimens examined in Romania, gonopores are separated by 3.5 annuli.Published as part of Ahmed, Raja Ben, Bielecki, Aleksander, Cichocka, Joanna M., Tekaya, Saïda, Gorzel, Małgorzata & Harrath, Abdul Halim, 2013, Erpobdellid leeches (Annelida, Clitellata, Hirudinida) from Tunisia: New records with the description of a new Trocheta species, pp. 440-454 in Zootaxa 3681 (4) on pages 441-443, DOI: 10.11646/zootaxa.3681.4.7, http://zenodo.org/record/21837