identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
DECA28F5E6FA5FD68665B9FA823058DD.text	DECA28F5E6FA5FD68665B9FA823058DD.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dugesia cylindrica Chen & Dong 2026	<div><p>Dugesia cylindrica Chen &amp; Dong sp. nov.</p><p>Figs 1, 4–8</p><p>Collection site and habitat.</p><p>On 4 December 2021, the specimens were collected from a small pool formed by a stream flowing down from the southern Taihang Mountains at an altitude of 346 m above sea level (a. s. l.). At the time of collection, the air temperature was 16 ° C and the water temperature was 13.7 ° C (Figs 1, 4 A, B). The water was clear and flowed slowly, and it was used as drinking water by local residents.</p><p>Material examined.</p><p>Holotype: • ZMHNU － LMG 3, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.07611&amp;materialsCitation.latitude=35.74111" title="Search Plazi for locations around (long 114.07611/lat 35.74111)">Laomugou village</a> (35°44'28"N, 114°4'34"E; alt. 350 m a. s. l.), Hebi City, Henan Province, China, 4 December 2021, coll. G-W Chen, Z-M Dong and co-workers, sagittal sections on 36 slides .</p><p>Paratypes: • ZMHNU － LMG 4 -6, ibid., sagittal sections on 41, 37, 40 slides, respectively; • RMNH.VER.22726.1, ibid., sagittal sections on 46 slides; • RMNH.VER.22726.2, ibid., sagittal sections on 45 slides; • ZMHNU － LMG 8, ibid., horizontal sections on 13 slides; • ZMHNU － LMG 7, 9, and 10, ibid., transverse sections on 24, 32 and 36 slides, respectively .</p><p>Other material: • ZMHNU － LZSXG 1, 5, 6, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=113.714165&amp;materialsCitation.latitude=36.16639" title="Search Plazi for locations around (long 113.714165/lat 36.16639)">Shibanyan village</a> (36°9'59"N, 113°42'51"E; alt. 1050 m a. s. l.), Linzhou City, Henan Province, sagittal sections on 12, 69, and 57 slides, respectively ; • ZMHNU － LZSXG 2, 7, ibid., horizontal sections on 25 and 9 slides; • ZMHNU － LZSXG 4, 8, ibid., transverse sections on 29 and 28 slides, respectively . • RMNH.VER.22727.1, ibid., sagittal sections on 32 slides .</p><p>• ZMHNU － BJHR 2-4, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=116.58&amp;materialsCitation.latitude=40.59361" title="Search Plazi for locations around (long 116.58/lat 40.59361)">Huairou village</a> (40°35'37"N, 116°34'48"E; alt. 510 m a. s. l.), Beijing City, sagittal sections on 37, 59, and 18 slides, respectively . • RMNH.VER.22728.1, ibid., sagittal sections on 56 slides .</p><p>• ZMHNU － XDH 1, 2, 5, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.000275&amp;materialsCitation.latitude=35.61472" title="Search Plazi for locations around (long 114.000275/lat 35.61472)">Xiaodianhe village</a> (35°36'53"N, 114°0'1"E; alt. 250 m a. s. l.), Weihui City, Henan Province, sagittal sections on 13, 19, and 21 slides, respectively ; • ZMHNU － XDH 4, ibid., horizontal sections on 21 slides; • ZMHNU － XDH 3, ibid., transverse sections on 27 slides, respectively . • RMNH.VER.22729.1, ibid., sagittal sections on 24 slides .</p><p>Diagnosis.</p><p>Dugesia cylindrica is characterized by the presence of the following features: a sac-shaped copulatory bursa that is located immediately posterior to the pharyngeal pocket; stubby, cylindrical penis papilla with a blunt tip; symmetrical openings of the oviducts into the bursal canal at the point where it communicates with the common atrium; vasa deferentia separately and symmetrically opening into the mid-lateral portion of the seminal vesicle; relatively large and pointed diaphragm; a long connecting duct between seminal vesicle and diaphragm; slightly ventrally displaced ejaculatory duct with a terminal opening. Anatomically, D. cylindrica is very similar to D. patula, but in the latter the copulatory bursa is located at some distance behind the pharyngeal pocket, whereas in the former the bursa lies immediately posterior to the pharyngeal pouch.</p><p>Etymology.</p><p>The specific epithet is derived from the Latin cylindrus, cylindrical, and alludes to the blunt and cylindrical penis papilla.</p><p>Karyology.</p><p>Eight intact specimens were randomly selected to prepare metaphase plates. In total, 168 metaphase plates were examined, in which 160 plates exhibited diploid chromosome complements of 2 n = 2 x = 16, while the remaining eight plates could not be determined due to either a lack of well-dispersed chromosomes or over-dispersed sets of chromosomes. All eight specimens exhibited diploid chromosome complements, and all chromosomes were metacentric. Karyotype parameters, including relative length, arm ratio, and centromeric index, are given in Table 2. Chromosomal plates and the idiogram are shown in Fig. 5.</p><p>Description.</p><p>Living asexual specimens measured 10–14 mm in length and 1.2–2.1 mm in width, while sexual specimens were 15–19 mm in length and 1.5–2.2 mm in width. The low-triangular head is provided with two blunt auricles and with two eyes, which are located in pigment-free patches. Each pigmented eyecup houses numerous light-sensitive cells. The dorsal surface of the body is dark brown, with a pale, broad margin. The ventral surface is lighter in color than the dorsal one (Fig. 4 C).</p><p>The pharynx is located at ca. 2 / 5 of the body length (as determined from the anterior margin), measuring approximately 1 / 6 of the body length (Fig. 4 C). The mouth opening is located at the posterior end of the pharyngeal pocket. Outer pharyngeal musculature is composed of a subepithelial layer of longitudinal muscles, followed by a thin layer of circular muscles; an extra inner layer of longitudinal muscles was not observed. The inner pharyngeal musculature consists of a subepithelial and thick layer of circular muscle, followed by a thin layer of longitudinal muscle.</p><p>In all specimens in which the ovaries could be examined (except LMG- 6), the gonads were not hyperplasic, occupying 1 / 3 of the dorsoventral space. The ovaries are located at a considerable distance behind the brain, i. e., at approximately 1 / 4 th of the distance between the brain and the root of the pharynx. The oviducts extend from the postero-dorsal wall of the ovaries towards the level of the genital pore along the ventral side of the body, where they curve towards the dorsal body surface to open symmetrically into the bursal canal at the point where the canal communicates with the common atrium. The oviducts are lined with a columnar, infranucleated epithelium. Cyanophil shell glands discharge their secretion into the vaginal region of the bursal canal around the oviducal openings. (Fig. 6 A, E).</p><p>A large, sac-shaped copulatory bursa is situated immediately posterior of the pharyngeal pocket and occupies most of the dorso-ventral space. The bursa is lined by a stratified, columnar, vacuolated, and nucleated epithelium; it is devoid of any surrounding musculature; some bursae contain large clumps of sperm, located within a spermatophore (LMG- 1 and 4). The bursal canal runs from the mid-posterior wall of the bursa in caudal direction, slightly to the left side of the male copulatory apparatus. The canal has a width of approximately 1 / 7 to 1 / 5 of the dorso-ventral space. At the level of the gonopore, the bursal canal curves ventrally to open into the common atrium. The bursal canal is lined with a ciliated epithelium with basal nuclei and shows a smooth inner wall and has a uniform diameter. The bursal canal is surrounded by three layers of muscle, a subepithelial, thin layer of longitudinal muscles, followed by a thick layer of circular muscle, which is bounded by a thin layer of longitudinal muscles, forming the ectal reinforcement layer. This ectal reinforcement musculature extends from the atrium to 3 / 4 of the bursal canal.</p><p>The small and rounded testes are located on the dorsal side, occupying 1 / 3 of the dorso-ventral space. Testicular follicles extend from the posterior level of the ovaries to the posterior end of the body. Mature spermatozoa are present in the testes.</p><p>The vasa deferentia expand to form spermiducal vesicles at the level of the pharynx and are filled with mature spermatozoa. At the level of the penis bulb, the spermiducal vesicles curve dorso-medially, decrease considerably in diameter, forming narrow ducts, and subsequently penetrate the penis bulb to open symmetrically into the mid-lateral section of the seminal vesicle (Fig. 6 D). The sperm ducts are lined with a nucleated epithelium and surrounded by a layer of circular muscle.</p><p>The sac-shaped seminal vesicle occupies a major portion of the penis bulb (Fig. 6 A, C) and is lined by a flat, nucleated epithelium. The vesicle is surrounded by a well-developed coat of irregularly, crosswise arranged muscle fibers. A well-developed and long duct extends from the posterior wall of seminal vesicle and opens into the ejaculatory duct via a diaphragm. This connecting duct is lined with an infranucleated epithelium, which is underlain by a subepithelial layer of intermingled muscle fibers. The diaphragm is located at approximately 2 / 3 of the length of the penis papilla and receives the openings of erythrophil penis glands (Fig. 6 A). The relatively large and pointed diaphragm opens into a very broad as well as short ejaculatory duct, which is lined with a cuboidal, infranucleated epithelium and is devoid of any discernible musculature. The short ejaculatory duct has an extremely broad opening at the blunt tip of the penis papilla. In several specimens, a spermatophore protruded from the opening of the ejaculatory duct at the tip of the penis papilla. With respect to the stubby, cylindrical penis papilla, the slightly ventrally displaced ejaculatory duct causes a slight asymmetry, with the dorsal lip being only marginally larger than the ventral lip. The penis papilla is covered with a nucleated epithelium, which is underlain by a subepithelial layer of circular muscle, followed by a layer of longitudinal muscle fibers (Fig. 6 A – C).</p><p>The genital atrium is divided into the common atrium and the male atrium, connected through a canal. The common atrium communicates with a gonoduct and leads to the gonopore, which is lined by a columnar epithelium and receives the openings of erythrophil cement glands (Fig. 6 A – C).</p><p>Reproduction.</p><p>The worms were collected at 16 ° C, and approximately one-third of all the worms were sexually mature in the field. After 3 months of laboratory culturing (at 16 ° C), the asexual specimens continuously sexualized and then produced infertile cocoons, as no juveniles hatched from these cocoons. Asexual reproductive behavior with broken tail regeneration was observed in asexual specimens.</p><p>Discussion.</p><p>Evidently, D. cylindrica is anatomically very similar to D. patula . However, the copulatory bursa of D. patula is located at a considerable distance (approximately 400–600 μm) behind the pharyngeal pocket, while its length is approximately twice the dorsoventral diameter of the body, i. e., measuring approximately 600–800 μm. This contrasts with the sac-shaped copulatory bursa located immediately posterior to the pharynx in D. cylindrica . In view of the fact that the position of the bursa appears to be different in D. patula and the molecular information suggests that it is different from D. cylindrica, the two species should be considered sibling species.</p><p>In addition, Dugesia cylindrica exhibits a combination of features that sets it immediately apart from other congeners, in particular, the presence of a ventrally displaced short ejaculatory duct with a terminal opening, as well as a duct between the seminal vesicle and diaphragm. The specimens from the three other localities are consistent with those from the type site (Fig. 7). Many species of Dugesia show similar anatomical features. However, there are only three Chinese species with a diaphragm located near the tip of the penis papilla, viz., D. tumida, D. postica, and D. patula (Chen et al. 2022; Wu et al. 2025). However, D. cylindrica cannot be synonymized with any of these species. Dugesia tumida possesses a large, symmetrical penial valve from the middle of which arises the small, distal section of the penis papilla; such a valve is absent in D. cylindrica . Dugesia postica possesses a large and long penis papilla with a small, dorsal bulge; such a bulge is absent in D. cylindrica . In addition, the small diaphragm of D. postica is different from the relatively large and pointed diaphragm of D. cylindrica .</p><p>The karyotype of D. cylindrica exhibits a diploid set (2 n = 2 x = 16), with a basic chromosome number of 8. In Dugesia species from China, chromosome portraits similar to that of D. cylindrica have been documented for D. constrictiva and D. musculosa . Evidently, the two species are anatomically dissimilar to D. cylindrica . Dugesia constrictiva has a laterally compressed seminal vesicle, and D. musculosa has a bursal canal provided with a strong, thick layer of circular muscle, which extends from the copulatory bursa to the common atrium and gonoduct, which is absent in D. cylindrica . However, the karyotype of D. musculosa exhibits a complex diploid set (2 n = 2 x = 16 and 16-7 th - 8 th), while aneuploidy is not observed in D. cylindrica .</p><p>Although D. cylindrica, D. patula, and D. postica belong to a relatively small clade in the phylogenetic tree (Fig. 2) and D. cylindrica has the lowest genetic distance with D. patula, notably, each species occupies its own branch, while they are anatomically different, albeit only marginally in the case of D. cylindrica and D. patula . The separate species status of D. cylindrica is also supported by the molecular species delimitation results.</p></div>	https://treatment.plazi.org/id/DECA28F5E6FA5FD68665B9FA823058DD	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	Su, Yi-Fan;Yu, Fu-Yu;Wu, Fan;Wang, Jing-Yi;Sluys, Ronald;Liu, De-Zeng;Wang, Lei;Dong, Zi-Mei;Chen, Guang-Wen	Su, Yi-Fan, Yu, Fu-Yu, Wu, Fan, Wang, Jing-Yi, Sluys, Ronald, Liu, De-Zeng, Wang, Lei, Dong, Zi-Mei, Chen, Guang-Wen (2026): Unveiling cryptic diversity: two new species of Dugesia from northern China, including one sibling species (Platyhelminthes, Tricladida, Dugesiidae). Zoosystematics and Evolution 102 (3): 783-805, DOI: 10.3897/zse.102.181547
F147F3D48BD65BA19C1374C9E358B10D.text	F147F3D48BD65BA19C1374C9E358B10D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dugesia elongata Chen & Dong 2026	<div><p>Dugesia elongata Chen &amp; Dong sp. nov.</p><p>Figs 1, 9–12</p><p>Collection site and habitat.</p><p>On 25 October 2021, the specimens were collected from a small pool formed by a stream flowing down from Baiyun Mountain at an altitude of 1100 m a. s. l., an air temperature of 8 ° C, and a water temperature of 6 ° C (Figs 1, 9 A, B). The water was clear and flowed slowly. At collection, individual worms were large, while mayfly larvae were present in the water.</p><p>Material examined.</p><p>Holotype: • ZMHNU － JJM 8, Baiyun Mountain in Song village (33°54'43"N, 111°83'49"E; alt. 1100 m a. s. l.), Luoyang County, Henan Province, China, 25 October 2021, coll. G-W. Chen, Z-M. Dong and co-workers, sagittal sections on 36 slides.</p><p>Paratypes: • ZMHNU － JJM 1, 2, 4, 8, ibid., sagittal sections on 39, 55, 65, and 55 slides, respectively; • ZMHNU － JJM 6, 7, 10, ibid., horizontal sections on 32, 16, and 29 slides; • ZMHNU － JJM 3 and 11, ibid., transverse sections on 49 and 51 slides, respectively . • RMNH.VER.22730.1, ibid., sagittal sections on 41 slides; • RMNH.VER.22730.2, ibid., sagittal sections on 32 slides .</p><p>Other material: • ZMHNU － SYXKZ 1-3, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=112.18361&amp;materialsCitation.latitude=35.358055" title="Search Plazi for locations around (long 112.18361/lat 35.358055)">Shuiyunxuan pub Yangcheng village</a> (35°21'29"N, 112°11'1"E; alt. 1150 m a. s. l.), Jincheng City, Shanxi Province, sagittal sections on 15, 14, and 15 slides, respectively . • RMNH.VER.22731.1, ibid., sagittal sections on 10 slides .</p><p>Diagnosis.</p><p>Dugesia elongata is characterized by the presence of the following features: relatively large worms; plump, barrel-shaped penis papilla; presence of an elongated, dumb-bell-shaped seminal vesicle; a well-developed connecting duct extending from the seminal vesicle and communicating with a low-conical diaphragm; ventrally displaced ejaculatory duct opening at the tip of the penial papilla, albeit at its ventral portion; asymmetrical openings of the oviducts, with the left oviduct opening into the ventral portion of the common atrium and the right oviduct opening into the bursal canal; copulatory bursa located at a short distance (approximately 487–696 μm) behind the pharyngeal pocket.</p><p>Etymology.</p><p>The specific epithet is derived from the Latin elongatus, having been stretched out, extended, and alludes to the long and dumb-bell-shaped seminal vesicle.</p><p>Karyology.</p><p>Eight intact specimens were randomly selected to prepare metaphase plates. A total of 185 metaphase plates were examined, in which 83 plates exhibited diploid chromosome complements of 2 n = 2 x = 16, while in 102 plates, chromosome complements were triploid with 2 n = 3 x = 24 chromosomes. All eight specimens exhibited mixoploid chromosome complements, and all chromosomes were metacentric. Karyotype parameters, including relative length, arm ratio, and centromeric index, are given in Table 3. Chromosomal plates and the idiogram are shown in Fig. 10.</p><p>Description.</p><p>The animals were rather large, and most of them were sexually mature. The asexual animals measured 15–30 mm in length and 1.8–3.8 mm in width, while the sexual worms were 25–38 mm in length and 2.8–3.9 mm in width. The low-triangular head is provided with two blunt auricles and two eyes, which are placed in pigment-free patches (Fig. 9 C). Each pigmented eyecup houses numerous photoreceptor cells. The dorsal surface is black-brown, except the pale, broad margin of the body; the ventral surface shows a brown hue, which is paler than the dorsal colouration.</p><p>Pharynx situated in the posterior region of the body, measuring approximately 1 / 7 th of the body length (Fig. 9 C). Mouth opening located at the posterior end of the pharyngeal pocket. Outer pharyngeal muscle layer is composed of a subepithelial, thin layer of longitudinal muscles, followed by a thin layer of circular muscles; no extra inner layer of longitudinal muscles was observed. The inner pharyngeal musculature consists of a subepithelial, thick layer of circular muscle, followed by a thin layer of longitudinal muscle.</p><p>In all specimens in which the ovaries could be examined (JJM- 5, 8, 9), the gonads were hyperplasic, occupying 1 / 3–2 / 3 of the dorsoventral space The oviducts extend from the dorsal wall of the ovaries and run to the posterior part of the body, and when posteriorly to the gonopore, they curve dorsally and also recurve and then open asymmetrically into the copulatory apparatus (Fig. 11 B). The right oviducal opening is higher than the left one, in that it is located at the point where the bursal canal communicates with the common atrium. The left oviduct opens into the lower, ventral portion of the common atrium. Cyanophil shell glands discharge their secretion into the vaginal region of the bursal canal, at the level of the oviducal openings.</p><p>The large and sac-shaped copulatory bursa is situated at a short distance behind the pharyngeal pocket, ranging between approximately 487–696 μm in all specimens in which it could be measured (JJM- 2, 4, 5, 8, 9). The bursa is a large and oblong, sac-like structure that occupies the entire dorso-ventral space, and is twice as long as it is high. Its lining consists of columnar, vacuolated cells with basal nuclei.</p><p>The bursal canal arises from the postero-dorsal wall of the bursa and then expands in diameter to become a wide duct. At the level of the gonopore the bursal canal makes a knee-shaped bend towards the ventral body surface to connect with the common atrium. The bursal canal is lined with a ciliated epithelium with basal nuclei. It is surrounded by three layers of muscle, the innermost layer being a thin layer of longitudinal muscles, the middle layer a slightly thicker layer of circular muscle, followed by a thin outermost layer of longitudinal muscles, which forms the ectal reinforcement layer and extends from the atrium to approximately 4 / 5 of the length of the bursal canal. The circular muscle layer is relatively thick along the ventral wall of the bursal canal but much thinner along its dorsal wall.</p><p>In all specimens in which the testes could be examined (except JJM- 4), the well-developed, albeit small, follicles are located on the dorsal side and extend from directly behind the ovaries to the posterior end of the body. At the level of the pharyngeal pocket, in several specimens (except JJM- 4), the vasa deferentia expand to form spermiducal vesicles, which are packed with sperm.</p><p>The barrel-shaped penis papilla is asymmetrical, in that the ejaculatory duct is ventrally displaced, opening at the tip of the papilla. The penis papilla is covered with a nucleated epithelium, which is underlain by a subepithelial layer of circular muscle, followed by a layer of longitudinal muscle fibers. A major portion of the dorsal wall of the penis papilla receives the openings of erythrophil glands, while a smaller part on its ventral wall is penetrated by openings of similar glands.</p><p>The penis bulb is lopsided, with its antero-ventral portion being near the ventral epidermis. That portion of the penis bulb houses the ventro-anterior portion of the seminal vesicle, which at its dorsal side narrows into a canal that runs anterodorsally and opens into another, again expanded portion of the seminal vesicle. Consequently, the seminal vesicle has the shape of a dumb-bell. The seminal vesicle is lined by a flat, nucleated epithelium and is surrounded by a layer of intermingled muscle fibers. The dorsally located portion of the dumb-bell symmetrically receives at its mid-ventral section the separate openings of the highly narrowed vasa deferentia, which are surrounded by a layer of circular muscles.</p><p>The anterior wall of the dorsally located portion of the seminal vesicle continues into a relatively long connecting duct that curves antero-ventrad and opens into a low-conical diaphragm, which opens into the ejaculatory duct. The diaphragm and the ejaculatory duct receive the abundant secretion of erythrophil penis glands (Figs 11 B, 13).</p><p>The genital cavity is divided into a common atrium and a male atrium, which communicate through a relatively narrow canal. The common atrium communicates with the bursal canal and also leads to the gonopore, which receives the openings of a large number of cement glands (Figs 11 B – D, 13).</p><p>In several specimens, a spermatophore protruded from the opening of the ejaculatory duct at the tip of the penis papilla.</p><p>Reproduction.</p><p>After 4 months of laboratory culturing, the asexual specimens continuously sexualized and produced cocoons. After approximately 20 days, five juveniles hatched from these cocoons. However, from then on, none of the worms produced any more cocoons.</p><p>Discussion.</p><p>The specimens from the other locality are consistent with those from the holotype site (Fig. 12). The coexistence of a long, dumb-bell-shaped seminal vesicle, a diaphragm, and a duct is found in only two Dugesia species, D. saccaria and D. verrucula . However, D. elongata cannot be synonymized with either of these two species. Dugesia saccaria has a dumbbell-shaped, muscularized hump located just anterior to the knee-shaped bend in the bursal canal. In addition, the ejaculatory duct opens terminally through the dorsal portion of the blunt tip of the penis papilla (Zeng et al. 2024), which contrasts with the ventral opening in D. elongata . Dugesia verrucula also has a dumbbell-shaped seminal vesicle surrounded by distinct musculature, like D. elongata . Unfortunately, this was not properly described by Wang et al. (2021 a), and it was also incorrectly described that in D. verrucula, the ejaculatory duct arises from the dorsal portion of the seminal vesicle. However, the ejaculatory duct always arises after, i. e., distally to the diaphragm. There is a difference, in that in D. verrucula, the vasa deferentia open into the proximal portion of the dumb-bell, whereas in D. elongata, the ducts open into the distal part of the dumb-bell-shaped seminal vesicle. However, the most characteristic feature of D. verrucula is the permanent dorsal bump on its penis papilla, which is absent in D. elongata (Wang et al. 2021 a).</p><p>In addition, D. elongata, D. verrucula, and D. constrictiva also belong to a small clade in the phylogenetic tree (Fig. 2). However, D. elongata and D. constrictiva are anatomically rather different (Wang et al. 2022). Dugesia constrictiva has a laterally compressed seminal vesicle and a cuboidal copulatory bursa, which are different from the elongated, dumb-bell-shaped seminal vesicle and the oblong, sac-like copulatory bursa of D. elongata . Furthermore, D. verrucula and D. constrictiva exhibit a diploid chromosome complement of 2 n = 2 x = 16, with a haploid number of n = 8, in contrast to the chromosome portrait of D. elongata, which shows a mixoploid karyotype with diploid complements of 2 n = 2 x = 16 and triploid sets of 2 n = 3 x = 24. The lowest COI and ITS-1 distance values between D. elongata and its congeners were 12.02 % ( D. elongata with D. constrictiva) and 1.66 % ( D. elongata with D. verrucula), respectively. Therefore, D. elongata is well separated from its congeners, which further supports its separate specific status as suggested by the anatomical and karyological analyses.</p></div>	https://treatment.plazi.org/id/F147F3D48BD65BA19C1374C9E358B10D	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	Su, Yi-Fan;Yu, Fu-Yu;Wu, Fan;Wang, Jing-Yi;Sluys, Ronald;Liu, De-Zeng;Wang, Lei;Dong, Zi-Mei;Chen, Guang-Wen	Su, Yi-Fan, Yu, Fu-Yu, Wu, Fan, Wang, Jing-Yi, Sluys, Ronald, Liu, De-Zeng, Wang, Lei, Dong, Zi-Mei, Chen, Guang-Wen (2026): Unveiling cryptic diversity: two new species of Dugesia from northern China, including one sibling species (Platyhelminthes, Tricladida, Dugesiidae). Zoosystematics and Evolution 102 (3): 783-805, DOI: 10.3897/zse.102.181547
