Abstract
A new species of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Xiangxi River, Shennongjia Forestry District, Hubei Province, China, is described on the basis of an integrative approach, involving morphology, and molecular systematics. The new species Dugesia saccaria A-T. Wang & Sluys, sp. nov. is characterized by the following features: a dumb-bell-shaped, muscularized hump located just anterior to the knee-shaped bend in the bursal canal; a ventrally displaced ejaculatory duct, which, however, opens terminally through the dorsal portion of the blunt tip of the penis papilla; a ventrally located seminal vesicle, giving rise to a vertically running duct that eventually curves downwards to communicate with the ejaculatory duct via a small diaphragm; oviducts opening asymmetrically into the dorsal portion of the common atrium and at the knee-shaped part of the bursal canal. The phylogenetic position of the new species was determined using four molecular markers (18S rDNA; ITS-1; 28S rDNA; COI), which suggested that it groups with other species of Dugesia from the Australasian and Oriental biogeographical regions.
References
- Álvarez-Presas, M., Baguñà, J. & Riutort, M. (2008) Molecular phylogeny of land and freshwater planarians (Tricladida, Platyhelminthes): from freshwater to land and back. Molecular Phylogenetics & Evolution, 47 (2), 555–568. https://doi.org/10.1016/j.ympev.2008.01.032
- Álvarez-Presas, M., Carbayo, F., Rozas, J. & Riutort, M. (2011) Land planarians (Platyhelminthes) as a model organism for fine-scale phylogeographic studies: understanding patterns of biodiversity in the Brazilian Atlantic Forest hotspot. Journal of Evolutionary Biology, 24, 887–896. https://doi.org/10.1111/j.1420-9101.2010.02220.x
- Baguñà, J., Carranza, S., Pala, M., Ribera, C., Giribet, G., Arnedo, M.A., Ribas, M. & Riutort, M. (1999) From morphology and karyology to molecules. New methods for taxonomical identification of asexual populations of freshwater planarians. A tribute to Professor Mario Benazzi. Italian Journal of Zoology, 66 (3), 207–214. https://doi.org/10.1080/11250009909356258
- Carranza, S., Giribet, G., Ribera, C. & Baguñà & Riutort, M. (1996) Evidence that two types of 18s rDNA coexist in the genome of Dugesia (Schmidtea) mediterranea (Platyhelminthes, Turbellaria, Tricladida). Molecular Biology & Evolution, 13 (6), 824–832. https://doi.org/10.1093/oxfordjournals.molbev.a025643
- Castresana, J. (2000) Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis. Molecular Biology and Evolution, 17 (4), 540–552. https://doi.org/10.1093/oxfordjournals.molbev.a026334
- Chen, Y.H., Chen, X.M., Wu, C.C. & Wang, A.T. (2015) A new species of the genus Dugesia (Tricladida: Dugesiidae) from China. Zoological Systematics, 40 237–249. https://doi.org/10.11865/zs.20150301
- Kalyaanamoorthy, S., Minh, B.Q., Wong, T.K.F., Haeseler, A.V. & Jermiin, L.S. (2017) Modelfinder: fast model selection for accurate phylogenetic estimates. Nature Methods, 14 (6), 587–589. https://doi.org/10.1038/nmeth.4285
- Katoh, K., Rozewicki, J. & Yamada, K.D. (2019) MAFFT online service: multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics, 20 (4), 1160–1166. https://doi.org/10.1093/bib/bbx108
- Kawakatsu, M., Oki, I. & Tamura, S. (1995) Taxonomy and geographical distribution of Dugesia japonica and D. ryukyuensis in the Far East. Hydrobiologia, 305 (1–3), 55–61. https://doi.org/10.1007/BF00036363
- Kumar, S., Stecher, G. & Tamura, K. (2016) Mega7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. Molecular Biology & Evolution, 33 (7), 1870–1874. https://doi.org/10.1093/molbev/msw054
- Kuraku, S., Zmasek, C.M., Nishimura, O. & Katoh, K. (2013) Aleaves facilitates on-demand exploration of metazoan gene family trees on MAFFT sequence alignment server with enhanced interactivity. Nucleic Acids Research, 41 (W1), W22–W28. https://doi.org/10.1093/nar/gkt389
- Lanfear, R., Frandsen, P.B., Wright, A.M., Senfeld, T. & Calcott, B. (2017) PartitionFinder 2: new methods for selecting partitioned models of evolution for molecular and morphological phylogenetic analyses. Molecular Biology and Evolution, 34 (3), 772–773. https://doi.org/10.1093/molbev/msw260
- Liu, Y., Song, X.Y., Sun, Z.Y., Li, W.X., Sluys, R., Li, S.F. & Wang, A.T. (2022) Addition to the known diversity of Chinese freshwater planarians: integrative description of a new species of Dugesia Girard, 1850 (Platyhelminthes, Tricladida, Dugesiidae). Zoosystematics and Evolution, 98 (2), 233–243. https://doi.org/10.3897/zse.98.83184
- Minh, B.Q., Nguyen, M.A.T. & Haeseler, A.V. (2013) Ultrafast approximation for phylogenetic bootstrap. Molecular Biology and Evolution, 30 (5), 1188–1195. https://doi.org/10.1093/molbev/mst024
- Nguyen, L.T., Schmidt, H.A., von Haeseler, A. & Minh, B.Q. (2015) IQ-TREE: A fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution, 32 (1), 268–274. https://doi.org/10.1093/molbev/msu300
- Nylander, J.A.A. (2004) MrModeltest. Version 2. Program distributed by the author. Evolutionary Biology Centre, Uppsala University, Uppsala. Available from: https://github.com/nylander/MrModeltest2 (accessed 22 August 2023)
- Rambaut, A. (2009) FigTree: tree figure drawing tool. Version 1.3.1. Institute of Evolutionary Biology, University of Edinburgh. Available from: http://tree.bio.ed.ac.uk/software/figtree (accessed 22 August 2023)
- Rambaut, A., Drummond, A.J., Xie, D., Baele, G. & Suchard, M.A. (2018) Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. Systematic Biology, 67 (5), 901–904. https://doi.org/10.1093/sysbio/syy032
- Ronquist, F., Teslenko, M., van der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) Mrbayes 3.2: efficient bayesian phylogenetic inference and model choice across a large model space. Systematic Biology, 61 (3), 539–542. https://doi.org/10.1093/sysbio/sys029
- Sluys, R. & Riutort, M. (2018) Planarian diversity and phylogeny. In: Rink, J.C. (Ed.), Planarian Regeneration: Methods and Protocols. Methods in Molecular Biology. Vol. 1774. Humana Press, Springer Science+Business Media, New York, New York, pp. 1–56. https://doi.org/10.1007/978-1-4939-7802-1_1
- Song, X.Y., Li, W.X., Sluys, R., Huang, S.X. & Wang, A.T. (2020) A new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from China, with an account on the histochemical structure of its major nervous system. Zoosystematics and Evolution, 96 (2), 431–447. https://doi.org/10.3897/zse.96.52484
- Wang, L., Dong, Z.M., Chen, G.W., Sluys, R. & Liu, D.Z. (2021a) Integrative descriptions of two new species of Dugesia from Hainan Island, China (Platyhelminthes, Tricladida, Dugesiidae). ZooKeys, 1028, 1–28. https://doi.org/10.3897/zookeys.1028.60838
- Wang, L., Chen, J., Dong, Z.M., Chen, G.W., Sluys, R. & Liu, D.Z. (2021b) Two new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the tropical monsoon forest in southern China. ZooKeys, 1059, 89–116. https://doi.org/10.3897/zookeys.1059.65633
- Wang, L., Wang, Y.X., Dong, Z.M., Chen, G.W., Sluys, R. & Liu, D.Z. (2021c). Integrative taxonomy unveils a new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the southern portion of the Taihang Mountains in northern China, with the description of its complete mitogenome and an exploratory analysis of mitochondrial gene order as a taxonomic character. Integrative Zoology, 17 (6), 1193–1214 https://doi.org/10.1111/1749-4877.12605
- Yang, Y., Li, J.Y., Sluys, R., Li, W.X., Li, S.F. & Wang, A.T. (2020) Unique mating behavior, and reproductive biology of a simultaneous hermaphroditic marine flatworm (Platyhelminthes, Tricladida, Maricola). Invertebrate Biology, 139, e12282. https://doi.org/10.1111/ivb.12282
- Zhao, C.M., Chen, W.L., Tian, Z.Q. & Xie, Z.Q. (2005) Altitudinal pattern of plant species diversity in Shennongjia Mountains, central China. Journal of Integrative Plant Biology, 47 (12), 1431–1449. https://doi.org/10.1111/j.1744-7909.2005.00164.x