identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
3413C31AA17E5ED483F18F224D3DBFBE.text	3413C31AA17E5ED483F18F224D3DBFBE.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dugesia fangchengensis Chen & Zhang 2026	<div><p>Dugesia fangchengensis Chen &amp; Zhang sp. nov.</p><p>Collection site, habitat and reproduction.</p><p>Specimens were collected from a stream in Yindian Village, Fangcheng County, Henan Province at an altitude of 200 m a. s. l. The water temperature was 25.5 ° C and pH was 6.0. None of the specimens were sexually mature when collected, and they reproduced asexually via fission in the laboratory. After being cultured under laboratory conditions for nearly two years, 12 specimens sexualized one after another and produced cocoons 40–45 days later. Subsequently, 7– 12 juveniles were hatched from each cocoon. Generally, the juveniles measure 1.25–4.01 mm in length and 0.45–0.70 mm in width (n = 23).</p><p>Material examined.</p><p>Holotype: • ZMHNU -FCYD 1, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=112.933334&amp;materialsCitation.latitude=33.366665" title="Search Plazi for locations around (long 112.933334/lat 33.366665)">Yindian Village</a> (33°22'N, 112°56'E; alt. 200 m a. s. l.), Fangcheng County, Henan Province, China (Fig. 1), Sep. 8 2020, coll. H-C Zhang, T-G Hu and W-J Zhao, sagittal sections on 18 slides.</p><p>Paratypes: • ZMHNU -FCYD 2, 3, ibid., sagittal sections on 23 and 25 slides, respectively; ZMHNU -FCYD 4, 5, ibid., horizontal sections on 5 and 6 slides, respectively; • ZMHNU -FCYD 6, ibid., transverse sections on 20 slides .</p><p>Etymology.</p><p>The specific epithet fangchengensis is derived from the place name Fangcheng County (Henan Province, China), combined with the Latin suffix - ensis (pertaining to). This nomenclature reflects the geographic location where its type specimen was found.</p><p>Diagnosis.</p><p>Dugesia fangchengensis is characterized by the presence of the following features: two oviducts symmetrically opening into the bursal canal; two vasa deferentia symmetrically opening into the dorsolateral portion of the seminal vesicle; two asymmetric bumps around the middle of the penis papilla gives it an approximately gyroscopic shape; a kidney-shaped seminal vesicle situated anteroventrally inside the penis bulb; a pointed diaphragm located at half the length of the penis papilla, separating the long duct extending from the seminal vesicle from the ejaculatory duct; a short ejaculatory duct displaced ventrally, with its terminal opening at the blunt tip of the penis papilla; an asymmetric penis papilla whose dorsal lip is thicker than the ventral one; a mixoploid karyotype comprising a diploid complement of 2 n = 2 x = 16 and a triploid set of 2 n = 3 x = 24, with all chromosomes metacentric.</p><p>Karyology.</p><p>A total of 122 metaphase plates were examined from six randomly selected specimens. Among them, 88 had a diploid karyotype of 2 n = 2 x = 16 and 21 showed a triploid complement of 2 n = 3 x = 24, with all chromosomes metacentric. In the remaining 13 metaphase plates, some had poorly dispersed chromosomes while others suffered from over-spread chromosome sets, which prevented accurate karyotype identification. Karyotype parameters are given in Suppl. material 2: table S 5. The first pair of chromosomes is clearly longer than the others, being 2.11 times the length of the shortest one. Chromosomal plates and idiogram of the karyotype are shown in Fig. 6 A – E.</p><p>Description.</p><p>Sexualized live specimens measure 16.0–19.0 mm in length and 1.8–2.5 mm in width (n = 12). The triangular head bears two blunt auricles and two eyes located in pigment-free patches. Each pigmented eyecup harbors numerous photoreceptor cells. The dorsal surface of the body is brownish, while the ventral surface is lighter than the dorsal (Fig. 6 F).</p><p>The cylindrical pharynx is positioned approximately at the mid-region of the body. It measures 2.93–4.03 mm long (n = 12), accounting for 1 / 5–1 / 6 of the body length. The mouth opening is located at the posterior end of the pharyngeal pocket. The outer pharyngeal musculature is composed of a layer of subepithelial longitudinal muscle followed by a layer of circular muscle. The inner pharyngeal musculature consists of a thick layer of subepithelial circular muscle followed by a thin layer of longitudinal muscle.</p><p>Two irregularly shaped hyperplastic ovaries are located ventrally a short distance posterior to the brain, nearly occupying the entire dorsoventral space. A single oviduct arises from the posterodorsal wall of each ovary and runs caudally along the ventral side of the body. At the level of the genital pore, the oviducts on both sides curve dorsomedially to open symmetrically into the junction where the bursal canal communicates with the common genital atrium (Figs 7 A, 8). Erythrophil shell glands discharge their secretions into the vaginal region, i. e., the section between the oviducal openings to the bursal canal (Figs 7 A, 8).</p><p>A large sac-shaped copulatory bursa lies immediately posterior to the pharyngeal pocket and occupies the entire dorsoventral space. The wall of the bursa is folded and lined by a columnar vacuolated epithelium with basal nuclei, being devoid of any surrounding musculature (Fig. 7 B). The bursal canal arises from the mid-posterior wall of the bursa and runs caudally along the dorsal side of the body. It is relatively narrow at its junction with the bursa and then widens markedly. At the level of the gonopore, the canal displays a rather abrupt ventral knee-shaped bending, narrows slightly, and finally opens into the common atrium (Figs 7 B, 8). The bursal canal is lined by infranucleated columnar ciliated epithelium. Beneath this epithelium lies a layer of longitudinal muscle, followed by a layer of circular muscle fibers; the circular muscle layer is thicker in the ventral side than in the dorsal (Fig. 8).</p><p>The numerous oval testes are located dorsally and arranged in two longitudinal bands on both sides of the midline of the body. They extend from the posterior level of the ovaries to well beyond the male copulatory apparatus. The vasa deferentia on both sides expand to form spermiducal vesicles filled with mature spermatozoa at the level of the pharyngeal pocket. When approaching the penis bulb, both sperm ducts curve dorsomedially and narrow rapidly. After penetrating the bulb wall, they extend ventrally and finally open symmetrically into the dorsal portion of the seminal vesicle (Figs 7 A, 7 C, 8). The prominent penis bulb lies posterior to the copulatory bursa and occupies 2 / 3 of the dorsoventral space (Figs 7 C, 7 D, 8).</p><p>The kidney-shaped seminal vesicle lies anteroventrally within the muscular penis bulb (Figs 7 C, 7 D, 8). A long duct extends from the posterior part of the vesicle into the penis papilla. A pointed diaphragm at the midpoint of the penis papilla separates the duct from the ejaculatory duct. The ejaculatory duct is ventrally displaced and opens at the blunt tip of the penis papilla. Accordingly, the dorsal lip of the penis papilla is thicker than the ventral one (Figs 7 C, 7 D, 8). A large dorsal bump and a small ventral one are present on the middle of the penis papilla, giving it an approximately gyroscopic shape (Figs 7 C, 7 D, 8). The penis papilla is located in the male atrium communicating with the common atrium, and the latter connects with a gonoduct that leads to the ventral gonopore (Figs 7 C, 7 D, 8).</p><p>Discussion.</p><p>The most characteristic feature of D. fangchengensis is the bumps around the middle of its penis papilla, with the dorsal bump more prominent and larger than the ventral one. Although this similar morphological character has been reported in D. verrucula Chen &amp; Dong, 2021, D. gemmulata Sun &amp; Wang, 2022, D. gibberosa Stocchino &amp; Sluys, 2017, and D. ancoraria Zhu &amp; Wang, 2024 (Stocchino et al. 2017; Wang et al. 2021 a; Liu et al. 2022; Zhu et al. 2024), D. fangchengensis cannot be identified as any of these species. In D. verrucula (Wang et al. 2021 a), only a single wart-like dorsal bump occurs at the base of the penis papilla, in contrast to the distinct dorsal bump located at the midpoint of the penis papilla in D. fangchengensis . In D. gemmulata (Liu et al. 2022), even though it possesses a distinct dorsal bump on the middle part of the penis papilla as does D. fangchengensis, there are other clear differences between the two. For example, its bursal canal has a muscular swelling absent in D. fangchengensis . With respect to D. gibberosa (Stocchino et al. 2017) and D. ancoraria (Zhu et al. 2024), there are two clear bumps, viz. a proximal one and a distal one on the dorsal lip of the penis papilla, in contrast to only one dorsal bump in D. fangchengensis . Furthermore, it is worth mentioning that the new species D. lushanensis also possesses a dorsal bump on the middle portion of its penis papilla, but other characteristic features such as the presence or absence of a connecting duct between the seminal vesicle and the diaphragm as well as the asymmetrical penial valve well clearly distinguish them.</p></div>	https://treatment.plazi.org/id/3413C31AA17E5ED483F18F224D3DBFBE	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Zhang, He-Cai;He, Jun-Hua;Zhang, Yue-Yue;Sun, Xiao-Juan;Shi, Chang-Ying;Chen, Guang-Wen;Liu, De-Zeng	Zhang, He-Cai, He, Jun-Hua, Zhang, Yue-Yue, Sun, Xiao-Juan, Shi, Chang-Ying, Chen, Guang-Wen, Liu, De-Zeng (2026): Integrative description of three new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Henan Province, central China. Zoosystematics and Evolution 102 (4): 893-909, DOI: 10.3897/zse.102.185506
2D109921C9AB5993824539715AC2D77E.text	2D109921C9AB5993824539715AC2D77E.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dugesia lushanensis Chen & Zhang 2026	<div><p>Dugesia lushanensis Chen &amp; Zhang sp. nov.</p><p>Collection site, habitat, and reproduction.</p><p>Specimens were collected from a stream in Huameigu Scenic Area, Lushan County, Henan Province at an altitude of 430 m a. s. l. The water temperature was 24.5 ° C and pH was 6.0. None of the worms were sexual at the time of collection, and they reproduced asexually by fission in the laboratory. After approximately two years of laboratory rearing, the immature specimens sexualized one after another. However, although sexually mature individuals were first observed on October 1, 2022, no cocoons have been detected to date.</p><p>Material examined.</p><p>Holotype: • ZMHNU -LSHM 1, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=112.316666&amp;materialsCitation.latitude=33.766666" title="Search Plazi for locations around (long 112.316666/lat 33.766666)">Huameigu Scenic Area</a> (33°46'N, 112°19'E; alt. 430 m a. s. l.), Lushan County, Henan Province, China (Fig. 1), Sep. 10, 2020, coll. H-C Zhang, T-G Hu and W-J Zhao, sagittal sections on 18 slides.</p><p>Paratypes: • ZMHNU -LSHM 2, 3, ibid., sagittal sections on 23 and 19 slides, respectively; • ZMHNU -LSHM 4, 5, ibid., horizontal sections on 9 and 6 slides; • ZMHNU -LSHM 6, ibid., transverse sections on 35 slides .</p><p>Etymology.</p><p>The specific epithet lushanensis is derived from the place name Lushan County (Henan Province, China), combined with the Latin suffix - ensis (pertaining to). This nomenclature reflects the geographic location where its type specimen was found.</p><p>Diagnosis.</p><p>Dugesia lushanensis is characterized by the following features: oviducts on both sides symmetrically opening into the bursal canal; vasa deferentia symmetrically opening into the dorsal region of the seminal vesicle; a highly asymmetrical penial valve present at the base of the penis papilla, whose dorsal part is distinctly larger than the ventral one; a well-developed diaphragm separating the ellipsoidal seminal vesicle from the inverted V-shaped ejaculatory duct; the ejaculatory duct opening subterminally through the ventral wall of the penial papilla; the penis papilla being markedly asymmetrical, with its dorsal lip thicker and longer than the ventral one; a dorsal bump located at mid-length of the penis papilla; diploid karyotype with chromosome complement of 2 n = 2 x = 16, and all chromosomes being metacentric.</p><p>Karyology.</p><p>A total of 122 metaphase plates were examined from six randomly selected specimens. Among these, 99 had a diploid karyotype of 2 n = 2 x = 16 with all chromosomes metacentric. In the remaining 23 metaphase plates, some had poorly dispersed chromosomes while others suffered from over-spread chromosome sets, which prevented accurate karyotype identification. Karyotype parameters including relative length, arm ratio, and centromeric index are given in Suppl. material 4: table S 3. The first pair of chromosomes is clearly longer than the others, being 2.71 times the length of the shortest one. A chromosomal metaphase plate and an idiogram of the karyotype are shown in Fig. 9 A – C.</p><p>Description.</p><p>The body length and width of live sexually mature specimens ranged from 24.0 to 28.0 mm and 2.6 to 3.0 mm, respectively (n = 11). The triangular head bears two blunt auricles and two eyes situated in pigment-free patches. Each pigmented eyecup contains numerous photoreceptor cells. The dorsal surface of the body is dark brownish, while the ventral surface is paler (Fig. 9 D).</p><p>The cylindrical pharynx measures 3.43–4.03 mm in length (n = 11). The mouth opening is located at the posterior end of the pharyngeal pocket. The outer pharyngeal musculature is composed of a thin layer of subepithelial longitudinal muscle, followed by a thick layer of circular muscle. The inner pharyngeal musculature consists of a thick layer of subepithelial circular muscle, followed by a thin layer of longitudinal muscle.</p><p>Two oval ovaries lie a short distance posterior to the brain and occupy the entire dorsoventral space (Fig. 10 A). From the posterodorsal wall of each ovary, an oviduct arises and runs posteriorly along the ventral side of the body. At the level of the gonopore, the paired oviducts curve dorsomedially and open symmetrically into the junction where the bursal canal communicates with the common genital atrium (Figs 10 B, 10 C, 10 F, 11). The vaginal region of the bursal canal receives secretions from erythrophil shell glands at the level of the oviduct openings.</p><p>The elongated sac-shaped copulatory bursa, located immediately posterior to the pharynx, lies near the ventral side of the body and occupies more than 1 / 2 of the dorsoventral space. The bursa is lined by a stratified columnar vacuolated epithelium with basal nuclei and is almost devoid of surrounding musculature (Figs 10 D, 10 F, 11). The bursal canal arises from the posterodorsal wall of the copulatory bursa and runs caudally along the left dorsal side of the male copulatory apparatus. Near the level of the gonopore, it bends medially to open into the common genital atrium (Figs 10 D, 10 E, 11). The bursal canal is lined with a nucleated columnar ciliated epithelium, which is underlain by a thin layer of longitudinal muscle followed by a thick circular muscle layer that is especially well developed in the ventral side. The common atrium connects with a gonoduct leading to the ventral gonopore.</p><p>Numerous near-spherical testicular follicles are distributed dorsally as two longitudinal bands on either side of the body midline. These follicles extend in a caudal direction from just behind the ovaries to a region well posterior to the copulatory apparatus. Behind the pharynx, the paired vasa deferentia dilate into spermiducal vesicles filled with sperm. At the level of the penis bulb, two sperm ducts narrow and penetrate the bulb. They initially run posterodorsally for a short distance, then curve ventrally and open symmetrically into the dorsal portion of the intrabulbar seminal vesicle (Figs 10 C, 10 E, 11). The roughly ellipsoidal seminal vesicle is positioned ventrally within the penis bulb. The bulb lies posterior to the copulatory bursa and occupies 2 / 3 of the dorsoventral space (Figs 10 E, 10 F, 11).</p><p>The seminal vesicle connects to the ejaculatory duct via a broad and blunt diaphragm located at the level of the base of the penis papilla (Figs 10 F, 11). The ejaculatory duct extends posterodorsally and then folds posteroventrally, resembling an inverted “V” and opens subterminally on the ventral side of the penis papilla; its dorsal lip is thicker and longer than the ventral one (Figs 10 F, 11). The penis papilla, whose base occupies 2 / 3 of the dorsoventral space, is nearly conical and possesses a well-developed muscular layer. A bump is present on the dorsocentral region of the penis papilla (Figs 10 F, 11). At the base of the penis papilla lies an asymmetrical penial valve, with the dorsal portion distinctly larger than the ventral one (Figs 10 E, 10 F, 11).</p><p>Discussion.</p><p>Dugesia lushanensis shows a combination of diagnostic features that distinguish it from its congeners. One main characteristic is the presence of a large asymmetrical parenchymatic penial valve. Penial valves, either symmetrical or asymmetrical, have been reported in the following species: D. ryukyuensis Kawakatsu, 1976, D. batuensis Ball, 1970, D. hymanae Sivickis, 1928, D. indonesiana Kawakatsu, 1973, D. uenorum Kawakatsu &amp; Mitchell, 1995, D. leporii Pala, Stocchino, Corso &amp; Casu, 2000, and D. tumida Chen &amp; Sluys, 2022 (Sluys et al. 1998; Corso et al. 2006; Stocchino et al. 2017; Chen et al. 2022). The last five species have symmetrical penial valves, while in D. lushanensis the valve is asymmetrical (Sluys et al. 1998; Corso et al. 2006; Chen et al. 2022). When compared with the first two species, D. ryukyuensis and D. batuensis, although D. lushanensis resembles them in possessing asymmetrical penial valve, it cannot be diagnosed as either taxa. Major differences include its roughly inverted V-shaped ejaculatory duct (straight and ventrally displaced in D. ryukyuensis and D. batuensis) and the absence of a connecting duct between the seminal vesicle and the diaphragm (present in D. ryukyuensis and D. batuensis) (Sluys et al. 1998; Stocchino et al. 2017). Notably, even though D. tumida is another Chinese species with a penial valve, D. lushanensis differs from it in multiple morphological characters. Firstly, the penial valve is asymmetrical in D. lushanensis but symmetrical in D. tumida . Additionally, its ejaculatory duct curves ventrally (dorsally curved in D. tumida); no long duct occurs between the seminal vesicle and the diaphragm (such a duct is present in D. tumida); and the diaphragm is large (small in D. tumida) (Chen et al. 2022).</p></div>	https://treatment.plazi.org/id/2D109921C9AB5993824539715AC2D77E	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Zhang, He-Cai;He, Jun-Hua;Zhang, Yue-Yue;Sun, Xiao-Juan;Shi, Chang-Ying;Chen, Guang-Wen;Liu, De-Zeng	Zhang, He-Cai, He, Jun-Hua, Zhang, Yue-Yue, Sun, Xiao-Juan, Shi, Chang-Ying, Chen, Guang-Wen, Liu, De-Zeng (2026): Integrative description of three new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Henan Province, central China. Zoosystematics and Evolution 102 (4): 893-909, DOI: 10.3897/zse.102.185506
67B7E6DE3E955431AA02A8840CE45C9D.text	67B7E6DE3E955431AA02A8840CE45C9D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dugesia tongbaiensis Chen & Zhang 2026	<div><p>Dugesia tongbaiensis Chen &amp; Zhang sp. nov.</p><p>Collection site, habitat, and reproduction.</p><p>Specimens were collected from a river in Sidaohe Village, Tongbai County, Henan Province at an altitude of 160 m a. s. l. The water temperature was 21.5 ° C and pH was 6.0. At field collection, none of the specimens were sexual. However, after approximately two years of laboratory rearing, 16 fissiparous asexual worms sexualized one after another. To date, these sexual individuals have not produced any cocoons.</p><p>Material examined.</p><p>Holotype: • ZMHNU -TBSD 1, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=113.38333&amp;materialsCitation.latitude=32.35" title="Search Plazi for locations around (long 113.38333/lat 32.35)">Sidaohe village</a> (32°21'N, 113°23'E; alt. 160 m a. s. l.), Tongbai County, Henan Province, China (Fig. 1), Sep. 7, 2020, coll. H-C Zhang, T-G Hu, and W-J Zhao, sagittal sections on 18 slides.</p><p>Paratypes: • ZMHNU -TBSD 2, 3, ibid., sagittal sections on 13 and 10 slides, respectively; • ZMHNU -TBSD 4, 5, ibid., horizontal sections on 4 and 6 slides; • ZMHNU -TBSD 6, ibid., transverse sections on 19 slides .</p><p>Etymology.</p><p>The specific epithet tongbaiensis is derived from the place name Tongbai County (Henan Province, China), combined with the Latin suffix - ensis (pertaining to). This nomenclature reflects the geographic location where its type specimen was found.</p><p>Diagnosis.</p><p>Dugesia tongbaiensis is characterized by the following features: asymmetrical openings of the oviducts into the bursal canal, with the right opening dorsal to the left one; two vasa deferentia symmetrically and laterally opening into the seminal vesicle; a long connecting duct interposed between the slender saclike seminal vesicle and the diaphragm; two well-developed adjacent diaphragms positioned at the distal half of the penis papilla, with the second larger than the first; the ejaculatory duct running a central course through the penis papilla with a terminal opening; a mixoploid karyotype with a diploid chromosome set of 2 n = 2 x = 16 and a triploid chromosome complement of 2 n = 3 x = 24, and all chromosomes being metacentric.</p><p>Karyology.</p><p>A total of 213 metaphase plates prepared from six randomly selected intact specimens were examined. Among them, 130 plates had a diploid karyotype of 2 n = 2 x = 16 and 56 showed a triploid complement of 2 n = 3 x = 24, with all chromosomes metacentric. In the remaining 27 metaphase plates, some had poorly dispersed chromosomes while others suffered from over-spread chromosome sets, which prevented accurate karyotype identification. Karyotype parameters including relative length, arm ratio, and centromeric index are given in Suppl. material 2: table S 4. The first pair of chromosomes is clearly longer than the others, being 2.21 times the length of the shortest one. Chromosomal plates and an idiogram of the karyotype are shown in Fig. 3 A – E.</p><p>Description.</p><p>Sexualized live specimens measured 13.0–18.0 mm in length and 2.3–4.0 mm in width (n = 16). The triangular head bears two blunt auricles and two eyes located in pigment-free patches. Each pigmented eyecup houses numerous photoreceptor cells. The dorsal body surface is brownish, while the ventral surface is paler (Fig. 3 F).</p><p>The cylindrical pharynx is positioned approximately at the mid-region of the body. It measures 4.6–6.3 mm long (n = 16), accounting for 1 / 3–1 / 4 of the body length. The mouth opening is located at the posterior end of the pharyngeal pocket. The musculature of the pharynx consists of an outer thin layer of subepithelial circular muscle followed by a thick layer of longitudinal muscle, while the inner pharyngeal musculature is composed of a thick subepithelial circular muscle followed by a thin longitudinal muscle. The gonopore is situated at about 1 / 5 of the length of the body, as measured from the posterior body margin.</p><p>Two hyperplastic ovaries are located ventrally just behind the brain and occupy almost the entire dorsoventral space. From the posterodorsal wall of each ovary, an oviduct arises and runs along the ventral side of the body caudally. Shortly posterior to the gonopore, the right oviduct curves dorsomedially and opens into the ventrally flexed segment of the bursal canal, whereas the left one opens into the bursal canal at the region where it meets the common genital atrium. Accordingly, the openings of two oviducts are asymmetric, with the right opening slightly dorsal to the left one (Figs 4 A, 5). The oviducts are lined with a columnar infranucleated epithelium.</p><p>The long saclike copulatory bursa is situated immediately posterior to the pharyngeal pocket and occupies 2 / 3 of the dorsoventral space (Figs 4 C, 5). It is lined by stratified columnar vacuolated epithelium provided with basal nuclei and is almost devoid of any surrounding muscles. The bursal canal originates from the dorsoposterior wall of the copulatory bursa and extends caudally along the dorsal side of the body; at the level of the gonopore, it curves anteroventrally to communicate with the common atrium (Fig. 5). It is lined with cylindrical infranucleated ciliated epithelium, which is underlain by a layer of longitudinal muscle followed by a thick layer of circular muscle. The erythrophil shell glands open into the vaginal section of the bursal canal between the oviducal openings (Figs 4 A, 5).</p><p>The oval-shaped testes of varying sizes lie on the dorsal side of the body. In fully sexually mature individuals, 60–70 testes, situated immediately behind the ovaries, are arranged on either side of the body midline and extend posteriorly nearly to the caudal tip. These testes are provided with numerous mature spermatozoa. Posterior to the copulatory bursa, the vasa deferentia on both sides dilate locally to form spermiducal vesicles that are packed with sperm. At the level of the penis bulb, the spermiducal vesicles fold back dorsally for a short distance, then narrow and curve posteromedially to penetrate the penis bulb. Finally, the two ducts open symmetrically into the posterolateral region of the seminal vesicle (Figs 4 B, 5). The penis bulb housing the slender saclike seminal vesicle lies posterior to the copulatory bursa and occupies 2 / 3 of the dorsoventral space (Figs 4 C, 4 D, 5).</p><p>The posterior part of the seminal vesicle extends as a long duct interposed into the penis papilla. Two well-developed adjacent diaphragms lie at the mid-distal region of the penis papilla, with the second one larger than the first. The short, broad ejaculatory duct runs centrally through the penis papilla and terminates in a wide opening. The penis papilla is cylindrical with a blunt-tip, and its base occupies 2 / 3 of the dorsoventral space (Figs 4 C, 4 D, 5). The genital atrium is subdivided into a common genital atrium and a male atrium. The common atrium connects with a gonoduct leading to the ventral gonopore (Figs 4 D, 5).</p><p>Discussion.</p><p>The presence of two diaphragms is one of the main diagnostic features of the new species D. tongbaiensis . Generally, species of Dugesia have a single diaphragm in the ejaculatory duct, while only a few possess double diaphragms, such as D. musculosa Chen &amp; Dong, 2024, D. semiglobosa Chen &amp; Dong, 2021, D. circumcisa Chen &amp; Dong, 2021, D. maghrebiana Stocchino, Manconi, Corso, Sluys, Casu &amp; Pala, 2009, D. didiaphragma de Vries, 1988, D. bijuga Harrath &amp; Sluys, 2019, D. mirabilis de Vries, 1988, and D. machadoi de Beauchamp, 1952 (de Vries 1988; Stocchino et al. 2009; Harrath et al. 2019; Wang et al. 2021 a, 2021 b, 2024). However, in the first five species, the ejaculatory duct runs a ventral course through the penis papilla, in contrast to the central trajectory in D. tongbaiensis . Although D. tongbaiensis, D. musculosa, D. circumcisa, and D. semiglobosa are all distributed in China and belong to the same Eastern Palearctic / Oriental / Australasian clade in molecular phylogenetic trees, they differ from one another in several morphological characteristics apart from the position of the ejaculatory duct passing through the penis papilla, such as the shape of the penis papilla and the presence or absence of a connecting duct between the seminal vesicle and the ejaculatory duct. In the new species D. tongbaiensis, a well-developed duct connects the intrabulbar seminal vesicle to the diaphragms, whereas this structure is absent in D. musculosa, D. circumcisa, and D. semiglobosa . With regard to the shape of the penis papilla, it is cylindrical in D. tongbaiensis, while it is conical in D. musculosa, hemispherical in D. semiglobosa, and bears a nozzle at the tip of the penis papilla in D. circumcisa (Wang et al. 2021 a, 2021 b, 2024). As for the aforementioned three Afrotropical species D. bijuga, D. mirabilis, and D. machadoi, although D. tongbaiensis resembles them in having a centrally running ejaculatory duct within the penis papilla, multiple distinct morphological features separate it from these taxa. Specifically, D. tongbaiensis lacks atrial folds, which are present in D. bijuga . Furthermore, the two diaphragms lie at the middle of the penis papilla in D. mirabilis, and in both D. machadoi and D. bijuga, the posterior diaphragm is situated at the base of the penis papilla, while in D. tongbaiensis the two diaphragms are close to the tip of the penis papilla (Harrath et al. 2019).</p></div>	https://treatment.plazi.org/id/67B7E6DE3E955431AA02A8840CE45C9D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Zhang, He-Cai;He, Jun-Hua;Zhang, Yue-Yue;Sun, Xiao-Juan;Shi, Chang-Ying;Chen, Guang-Wen;Liu, De-Zeng	Zhang, He-Cai, He, Jun-Hua, Zhang, Yue-Yue, Sun, Xiao-Juan, Shi, Chang-Ying, Chen, Guang-Wen, Liu, De-Zeng (2026): Integrative description of three new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Henan Province, central China. Zoosystematics and Evolution 102 (4): 893-909, DOI: 10.3897/zse.102.185506
