identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
062CC7ED45FA5BD58D7BDEEB835A4C51.text	062CC7ED45FA5BD58D7BDEEB835A4C51.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Psilochasmus oxyurus (Creplin 1825)	<div><p>Psilochasmus oxyurus (Creplin, 1825)</p><p>Fig. 3</p><p>Description.</p><p>Based on six adult specimens (measurements of illustrated specimen are given in text; measurements of entire series are given in Table 2). Body elongate, cylindrical, somewhat wider near level of testes, 4,189 × 615, with narrow muscular, retractile tail-like process. Body length to width ratio 6.8. Ratio of body width at level of testes to body width at level of ventral sucker 1.0. Tegument armed. Forebody length represents 26 % of body length. Oral sucker subterminal, elongate-oval, 294 × 282, sometimes withdrawn under surface of tegument. Ventral sucker protuberant with deep cavity, consisting of strongly muscular portion and extensive surrounding sub-tegumental rim, larger than oral sucker, 609 × 586. Oral sucker to ventral sucker width ratio 0.5. Prepharynx short, not observed in holotype. Pharynx muscular, elongate-oval, smaller than oral sucker, 145 × 127. Oral sucker to pharynx length ratio 2.0; oral sucker to pharynx width ratio 2.2. Esophagus muscular, bifurcating anterior to level of ventral sucker, 328. Ceca thin-walled, extending to near posterior end of body.</p><p>* Only observed in holotype.</p><p>Testes tandem, in posterior half of body, weakly or strongly lobate. Anterior testis 485 × 258; posterior testis 517 × 236. Cirrus-sac elongate, slender, reaching level of ovary or anterior to it, 1,197 × 100. Internal seminal vesicle unipartite, tubular, with broader proximal part. Pars prostatica indistinct. Genital pore immediately anterior to level of ventral sucker.</p><p>Ovary oval, median or submedian, pretesticular, 180 × 148. Mehlis’ gland between level of ovary and anterior testis. Uterine seminal receptacle present. Laurer’s canal not observed. Vitellarium distributed throughout most of hind body length, absent in tail; most follicles lateral to gonads, uterus and cirrus-sac. Vitelline reservoir between level of ovary and anterior testis. Eggs not numerous, ≤ 17 present, 79–99 × 49–60.</p><p>Excretory pore subterminal. Excretory bladder not readily observed.</p><p>Taxonomic summary.</p><p>Type host: Aythya marila (L.) ( Anseriformes: Anatidae).</p><p>Host in this study: Anas crecca L. ( Anseriformes: Anatidae).</p><p>Site of infection: small intestine.</p><p>Locality in this study: Skadovsk District, Kherson Region, Ukraine (46°07'55.6"N, 32°13'40.7"E).</p><p>Specimens deposited: Vouchers: HWML -218106, labeled Anas crecca, small intestine, Skadovsk District, Kherson Region, Ukraine, 31 Aug 2011, coll. V. V. Tkach.</p><p>Representative DNA sequences: PX 118872 (ITS region + 28 S); PX 114583 (nad 1).</p><p>Remarks.</p><p>The original description of the species by Creplin (1825) and redescription by Braun (1902) lack most details and measurements provided in descriptions of other echinostomatoid taxa. Despite this, the morphology (quantitative and qualitative characters) of our specimens of P. oxyurus closely conforms to the original description by Creplin (1825) and redescription by Braun (1902) (Table 2). Importantly, we provide molecular data associated with our described specimens of P. oxyurus .</p></div>	https://treatment.plazi.org/id/062CC7ED45FA5BD58D7BDEEB835A4C51	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	Achatz, Tyler J.;Morton, Lauren B.;Orlofske, Sarah A.;Brant, Sara V.;Montes, Martin M.;Bondone, Federico;Tkach, Vasyl V.	Achatz, Tyler J., Morton, Lauren B., Orlofske, Sarah A., Brant, Sara V., Montes, Martin M., Bondone, Federico, Tkach, Vasyl V. (2025): Description of two new species of Psilochasmus Lühe, 1909 (Digenea, Psilostomidae), with remarks on the diversity of the genus and a key to its species. ZooKeys 1254: 149-170, DOI: 10.3897/zookeys.1254.162728
C27DBD6E75085C65AB7658AEF60E9353.text	C27DBD6E75085C65AB7658AEF60E9353.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Psilochasmus slavaukrainii Achatz, Morton, Orlofske & Tkach 2025	<div><p>Psilochasmus slavaukrainii Achatz, Morton, Orlofske &amp; Tkach sp. nov.</p><p>Fig. 4 a, b</p><p>Type material.</p><p>Holotype: HWML -218107, labeled Anas clypeata, small intestine, Skadovsk District, Kherson Region, Ukraine, 9 Nov 2002, coll. V. V. Tkach . Paratypes (3 slides), labeled identical to holotype: HWML -218108. Vouchers (juveniles; 1 slide): HWML -218109, labeled Tadorna ferruginea, small intestine, Skadovsk District, Kherson Region, Ukraine, 30 Oct 2002, coll. V. V. Tkach .</p><p>Description.</p><p>Based on four adult specimens (measurements of holotype are given in text; measurements of entire series are given in Table 2). Body elongate, 3,219 × 759, widest near level of testes; forebody cylindrical; hindbody with strong lateral expansion with narrow muscular, retractable tail-like process,. Body length to width ratio 4.2. Ratio of body width at level of testes to body width at level of ventral sucker 1.7. Tegument armed. Forebody length represents 35 % of body length. Oral sucker subterminal, oval, 259 × 206. Ventral sucker protuberant with deep cavity, consisting of strongly muscular portion and extensive surrounding sub-tegumental rim, 312 × 426. Oral sucker to ventral sucker width ratio 0.5. Prepharynx not observed. Pharynx muscular, elongate-oval, 143 × 100. Oral sucker to pharynx length ratio 1.8; oral sucker to pharynx width ratio 2.1. Esophagus muscular, bifurcating anterior to level of ventral sucker, 482. Ceca thin-walled, extending posterior to level of posterior testis.</p><p>Testes tandem, in posterior half of body, lobate. Anterior testis 269 × 238; posterior testis 345 × 199. Cirrus-sac elongate, slender, reaching level of ovary or anterior to it, 421 × 80. Internal seminal vesicle unipartite, tubular, with broader proximal part. Pars prostatica indistinct. Genital pore immediately anterior to anterior margin of ventral sucker.</p><p>Ovary oval, median or submedian, pretesticular, posterior to level of ventral sucker, 128 × 128. Mehlis’ gland between level of ovary and anterior testis. Uterine seminal receptacle present. Laurer’s canal not observed. Vitellarium distributed throughout most of hindbody length, absent in tail; most follicles lateral to gonads, uterus and cirrus-sac. Vitelline reservoir between level of ovary and anterior testis (not readily observed in holotype). Eggs few, 5 in holotype, 84–101 × 50–66.</p><p>Excretory pore positioned near tip of tail. Excretory bladder not readily observed.</p><p>Taxonomic summary.</p><p>Type host: Anas clypeata (L.) ( Anseriformes: Anatidae).</p><p>Other host (only juveniles collected): Tadorna ferruginea (Pallas) ( Anseriformes: Anatidae).</p><p>Site: small intestine.</p><p>Locality: Skadovsk District, Kherson Region, Ukraine; 46°26'38.3"N, 32°01'44.9"E.</p><p>Representative DNA sequences: PX 118873 (ITS region + 28 S); PX 114584 (nad 1).</p><p>Etymology.</p><p>This species is named in honor of the national salute in the country in which it was collected.</p><p>Diagnosis.</p><p>These digeneans clearly belong to Psilochasmus based on the echinostome-like body that lacks a cephalic collar and the presence of a protrusible, retractile, muscular tail-like process at the posterior end of the body. The body of P. slavaukrainii sp. nov. has a strong lateral expansion immediately posterior to the level of the ventral sucker that is absent in properly relaxed mature congeners. It is noteworthy that the original description of P. agilis by Travassos (1921) did not mention such a lateral expansion. However, Szidat (1957) illustrated ‘ younger’ P. agilis specimens (referred to as P. oxyurus) that exhibited this trait. At the same time, the mature adult stage illustrated by Szidat (1957) had only a slight widening of the body.</p><p>Psilochasmus slavaukrainii sp. nov. is a much smaller digenean compared with P. agilis . For instance, the body length of mature specimens is only 2,076 –3,219, whereas the body length of mature P. agilis exceeds 4,000. The forebody of the new species represents 30–36 % of the body length, whereas in P. agilis it is approximately 25 %. The new species is distributed in the Palearctic, whereas P. agilis is restricted to the Neotropics, and possibly Nearctic (see Discussion below). Psilochasmus slavaukrainii sp. nov. and P. cf. agilis differ by 2.1 % in the partial 28 S sequences and 16.8–17.2 % in the partial nad 1 sequences (Table 3).</p><p>* 28 S region from this specimen is identical to the 28 S sequence of P. oxyurus collected from Anas platyrhynchos in Kherson region, Ukraine available in GenBank (AF 151940).</p><p>The oral sucker to pharynx width ratio of P. slavaukrainii sp. nov. (2.1–2.7) is greater than in P. longicirratus (1.6 based on the original drawing). The new species is shorter (2,076 –3,219) compared to P. longicirratus (3,740 –5,000). Furthermore, the suckers and pharynx of P slavaukrainii sp. nov. are much smaller (oral sucker 192–259 × 195–206; ventral sucker 312–389 × 330–426; pharynx 103–143 × 73–100) compared to P. longicirratus (oral sucker 340 in diameter; ventral sucker 640 in diameter; pharynx 255 × 204). However, the testes of the new species are typically larger (anterior testis 217–269 × 222–238; posterior testis 221–345 × 157–208) compared to P. longicirratus (testes 170 in diameter). The eggs of the new species (84–101) are much smaller than those of P. longicirratus (116–124).</p><p>Psilochasmus slavaukrainii sp. nov. and P. oxyurus are very similar morphologically. The oral sucker to pharynx length ratio is generally smaller in the new species (1.4–1.9, mean 1.8) compared to P. oxyurus (1.8–2.3, mean 2.0 in our material). The post-testicular field is longer in the new species (27–30 %, mean 28 % of body length) compared to P. oxyurus (23 % of body length based on the illustration of Braun (1902) (14–25 %, mean 19 % of body length in present material). Despite being similar morphologically, these species differ by 2.0 % in the 28 S, 11.5 % in the 5.8S + ITS 2, and 16.4–16.8 % in the partial nad 1 sequences (Table 3).</p><p>Psilochasmus slavaukrainii sp. nov. has a well-developed esophagus (182–482 long), whereas the ceca of P. skrjabini bifurcate almost immediately posterior to the pharynx. The new species is much smaller in body length (2,076 –3,219 in the new species vs 6,750 in P. skrjabini), oral sucker width (195–206 in P. slavaukrainii sp. nov. vs 400 in P. skrjabini), ventral sucker size (312–389 × 330–426 in P. slavaukrainii sp. nov. vs 780 × 600 in P. skrjabini) and pharynx size (103–143 × 73–100 in P. slavaukrainii sp. nov. vs 200 × 250 in P. skrjabini).</p><p>Psilochasmus slavaukrainii sp. nov. lacks a distinct additional muscular sphincter at the anterior end of the pharynx, whereas such a structure is present in P. sphincteropharynx . The pharynx of P. slavaukrainii sp. nov. (103–143 × 73–100) is also smaller than P. sphincteropharynx (150–162 × 160–170). Psilochasmus slavaukrainii sp. nov. has a smaller body (2,076 –3,219) than P. sphincteropharynx (4,200 –4,250). The oral sucker of these species is similar in size, or slightly smaller in the new species, whereas the ventral sucker is noticeably larger in the new species (312–389 × 330–426) compared to P. sphincteropharynx (270 in diameter). Eggs are somewhat shorter in P. slavaukrainii sp. nov. (84–101) compared to those of P. sphincteropharynx (105–110).</p><p>It is worth noting that the specimen of P. oxyurus illustrated by Bykhovskaja-Pavlovskaja (1962: fig. 68), from the mallard Anas platyrhynchos L. (collected from an unknown locality in the former Soviet Union) appears to be essentially identical to P. slavaukrainii sp. nov.</p><p>No variation was detected in ribosomal loci (ITS 1 + 5.8S + ITS 2 + 28 S) between the two isolates of the new species, whereas a 0.4 % variation was observed between two isolates in the partial nad 1 sequences (Table 3).</p></div>	https://treatment.plazi.org/id/C27DBD6E75085C65AB7658AEF60E9353	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	Achatz, Tyler J.;Morton, Lauren B.;Orlofske, Sarah A.;Brant, Sara V.;Montes, Martin M.;Bondone, Federico;Tkach, Vasyl V.	Achatz, Tyler J., Morton, Lauren B., Orlofske, Sarah A., Brant, Sara V., Montes, Martin M., Bondone, Federico, Tkach, Vasyl V. (2025): Description of two new species of Psilochasmus Lühe, 1909 (Digenea, Psilostomidae), with remarks on the diversity of the genus and a key to its species. ZooKeys 1254: 149-170, DOI: 10.3897/zookeys.1254.162728
D2E7F4B51BC7570095BCB9F15BDFA619.text	D2E7F4B51BC7570095BCB9F15BDFA619.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Psilochasmus urbeni Achatz, Morton, Orlofske & Tkach 2025	<div><p>Psilochasmus urbeni Achatz, Morton, Orlofske &amp; Tkach sp. nov.</p><p>Fig. 4 c, d</p><p>Type material.</p><p>Holotype: HWML -218110, labeled Aythya marila, small intestine, Stump Lake, Nelson County, North Dakota, USA, 6 Nov 2006, coll. V. V. Tkach . Paratypes: HWML -218111 (hologenophore), Aythya affinis, small intestine, Lake Winnibigoshish, Itasca County, Minnesota, USA, 1 Nov 2007, coll. V. V. Tkach ; UWSP–PARA (3 paratypes): Aythya affinis, small intestine, Green Bay, Lake Michigan, Oconto County, Wisconsin, USA, 24 Nov 2019, coll. S. A. Orlofske .</p><p>Description.</p><p>Based on 5 specimens (measurements of holotype are given in text; measurements of entire series are given in Table 2). Body elongate, cylindrical, widest near level of testes, 6,711 × 1,307, with narrow, retractable, muscular tail-like process. Body length to width ratio 5.1. Ratio of body width at level of testes to body width at level of ventral sucker 1.3. Tegument armed. Forebody length represents 35 % of body length. Oral sucker subterminal, subspherical, 422 × 417. Ventral sucker protuberant with deep cavity, consisting of strongly muscular portion and extensive surrounding sub-tegumental rim, 785 × 830. Oral sucker to ventral sucker width ratio 0.5. Prepharynx not observed. Pharynx muscular, subspherical, 287 × 290. Oral sucker to pharynx length ratio 1.5; oral sucker to pharynx width ratio 1.4. Esophagus muscular, bifurcating immediately anterior to level of ventral sucker, 675. Ceca thin-walled, extending to near posterior end of body.</p><p>Testes tandem, in posterior half of body, lobulated. Anterior testis 705 × 436; posterior testis 901 × 408. Cirrus-sac elongate, slender, reaching level of ovary or anterior to it, 1,690 × 226. Internal seminal vesicle unipartite, tubular, with broader proximal part. Pars prostatica indistinct. Genital pore immediately anterior to level of ventral sucker.</p><p>Ovary subspherical, median or submedian, pretesticular, posterior to level of ventral sucker, 232 × 238. Mehlis’ gland between level of ovary and anterior testis. Uterine seminal receptacle present. Laurer’s canal not observed. Vitellarium distributed throughout most of hind body length, absent in tail, with most follicles lateral to gonads, uterus and cirrus-sac, confluent posterior to testes. Vitelline reservoir (not readily observed in holotype) between level of ovary and anterior testis. Eggs numerous, 42 in holotype, ≤ 137 in paratype, 90–104 × 62–70.</p><p>Excretory pore not observed. Excretory bladder not readily observed.</p><p>Taxonomic summary.</p><p>Type host: Aythya marila (L.) ( Anseriformes: Anatidae).</p><p>Other hosts: Aythya affinis, Melanitta americana (Swainson) .</p><p>Site: small intestine.</p><p>Type locality: Stump Lake, Nelson County, North Dakota, USA; 47°53'15.5"N, 98°18'11.3"W.</p><p>Other localities: Lake Winnibigoshish, Itasca County, Minnesota, U. S. A.; 47°27'14.8"N, 94°16'30.9"W; Green Bay, Lake Michigan, Oconto County, Wisconsin, USA; 44°48'51.2"N, 87°52'54.7"W; Monroe County, Florida.</p><p>Specimens deposited: The type series consists of 5 fully mature specimens (one is a hologenophore).</p><p>Representative DNA sequences: PX 118875 (5.8S + ITS 2 + 28 S), PX 114586 (nad 1).</p><p>Etymology.</p><p>This species is named for Bruce Urben (Wisconsin Waterfowl Association) and his family for their leadership in waterfowl conservation, support of wetland habitat restoration, and donation of numerous birds for parasitology research.</p><p>Diagnosis.</p><p>Psilochasmus urbeni sp. nov. belongs to the genus based on its echinostome-like body that lacks a cephalic collar and the presence of a protrusible, retractile, muscular tail-like process at the posterior end of the body. This new species has an oral sucker that is only slightly wider than the pharynx (oral sucker to pharynx width ratio 1.1–1.5, mean 1.3), whereas that of other Psilochasmus spp. is typically much wider than the pharynx (oral sucker to pharynx width ratio 1.6–2.8 based on the present study, original descriptions and illustrations).</p><p>The body length of P. urbeni sp. nov. (6,000 –7,020) is greater than P. agilis (4,500), although the suckers and ovary in the two species are similar in size. The esophagus of P. urbeni sp. nov. (537–923) is much longer compared to P. agilis (270 based on the original illustration). Psilochasmus urbeni sp. nov. and P. cf. agilis differ by 0.1 % in the 28 S and 9.4–9.8 % in the partial nad 1 sequences (Table 3).</p><p>Psilochasmus urbeni sp. nov. is much longer than P. longicirratus (body length 6,000 –7,020 in the new species vs 3,740 –5,000 in P. longicirratus). Despite the difference in body length, all structures and organs overlap in size, except for testes; the testes of the new species are much larger (anterior testis 327–810 × 248–617; posterior testis 612–951 × 234–528) compared to P. longicirratus (testes 170 in diameter). The eggs of P. urbeni sp. nov. (87–113, mean 99) are generally smaller than in P. longicirratus (116–124).</p><p>Similar to the previous comparisons, the body length of P. urbeni sp. nov. (6,000 –7,020) is greater than in P. oxyurus (2,415 –4,189 in new material). The esophagus of P. urbeni sp. nov. (537–923) is much longer than in P. oxyurus (328–456 in new material). Both suckers and the pharynx are larger in the new species compared to P. oxyurus (Table 2). The oral sucker to pharynx length ratio is noticeably smaller in P. urbeni sp. nov. (1.1–1.5, mean 1.4) than in P. oxyurus (1.8–2.3, mean 2.0 in new material). These species differ by 0 % in the 28 S, 0.2 % in the 5.8S + ITS 2, and 6.3 % in the partial nad 1 sequences (Table 3).</p><p>Psilochasmus urbeni sp. nov. has a well-developed esophagus (537–923 long), whereas the cecal bifurcation of P. skrjabini is situated essentially immediately posterior to the pharynx. The oral sucker of P. urbeni sp. nov. (318–455) is also much longer than that of P. skrjabini (200).</p><p>The body of P. urbeni sp. nov. lacks the strong lateral expansion immediately posterior to the level of the ventral sucker that is present in P. slavaukrainii sp. nov. Psilochasmus urbeni sp. nov. is also a much larger digenean compared to P. slavaukrainii sp. nov. in most regards, including body, sucker, and pharynx sizes as well as esophageal length (Table 2). For example, the body length of P. urbeni sp. nov. is more than twice that of P. slavaukrainii sp. nov. (6,000 –7,020 vs 2,076 –3,219). These species differ by 2 % in the 28 S, in 11.5 % in the 5.8S + ITS 2, and 15.3–16.2 % in the partial nad 1 sequences (Table 3).</p><p>Psilochasmus urbeni sp. nov. lacks a distinct additional muscular sphincter at the anterior end of pharynx, which is present in P. sphincteropharynx . Otherwise, P. urbeni sp. nov. is a larger species as compared with P. sphincteropharynx . The body length of P. urbeni sp. nov. (6,000 –7,020) is noticeably greater than that of P. sphincteropharynx (4,200 –4,250). Both suckers and the pharynx are larger in the new species (oral sucker 318–455 × 284–417; ventral sucker 402–785 × 520–830; pharynx 224–301 × 194–376) compared with P. sphincteropharynx (oral sucker 240–270 × 220–230; ventral sucker 270 in diameter; pharynx 150–162 × 160–170).</p><p>Intraspecific variation of 0.2–0.9 % was detected among nad 1 sequences of P. urbeni sp. nov. (Table 3).</p></div>	https://treatment.plazi.org/id/D2E7F4B51BC7570095BCB9F15BDFA619	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	Achatz, Tyler J.;Morton, Lauren B.;Orlofske, Sarah A.;Brant, Sara V.;Montes, Martin M.;Bondone, Federico;Tkach, Vasyl V.	Achatz, Tyler J., Morton, Lauren B., Orlofske, Sarah A., Brant, Sara V., Montes, Martin M., Bondone, Federico, Tkach, Vasyl V. (2025): Description of two new species of Psilochasmus Lühe, 1909 (Digenea, Psilostomidae), with remarks on the diversity of the genus and a key to its species. ZooKeys 1254: 149-170, DOI: 10.3897/zookeys.1254.162728
