Concepts in Animal Parasitology, Chapter 44: Haematoloechidae Odening, 1964 (Family)

Chapter 44 in Concepts in Animal Parasitology on the family Haematoloechidae Odening, 1964 by Virginia León-Règagnon. 2024. S. L. Gardner and S. A. Gardner, editors. Zea Books, Lincoln, Nebraska, United States. doi: 10.32873/unl.dc.ciap04

First record of the genus choledocystus (Trematoda: Plagiorchiidae) for amphibians of the chacoan region in argentina

This is the first record of the trematode Choledocystus incurvatum and Choledocystus elegans in Argentinean amphibians collected in two localities of the Chacoan region. The first trematode species was found infecting the small intestine of Pseudis paradoxa Linnaeus, captured near the city of Corrientes, Corrientes Province; the second species was found infecting the gall-bladder of Lepidobatrachus laevis Budgget, captured in Ingeniero Juárez, Formosa Province. Morphology of these species was studied in detail using light microscopy and scanning electron microscopy (SEM), and compared with previous studies of Brazilian and Venezuelan specimens. Morphological descriptions of these parasites are provided to supplement existing data. Choledocystus incurvatum was characterized using molecular methods by sequencing and analyzing rDNA. Regarding metric characters of C. incurvatum, the Argentinean specimens show some differences in body and egg size (some larger than Venezuelan specimens). For C. elegans the specimen shows smaller body size than Brazilian specimens. SEM observations of C. incurvatum showed tegument covered with triangular spines and confirmed presence of a sucker-like structure around the genital atrium. The morphological and genetic data on C. incurvatum contribute to a more thorough diagnosis of the genus. Moreover, this report represents the first occurrence of this genus in the Argentine Chacoan region.Fil: Hamann, Mónika Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: León Règagnon, Virginia. Universidad Nacional Autónoma de México; MéxicoFil: Fernández, María Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Gonzalez, Cynthya Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

First report of the genus Physaloptera (Nematoda: Physalopteridae) in Lithobates montezumae (Anura: Ranidae) from Mexico

AbstractNematode third stage larvae of the genus Physaloptera (Nematoda: Physalopteridae) were recovered from the stomach of Lithobates montezumae (Anura: Ranidae) collected in the Pedregal de San Angel Ecological Reserve in Mexico D. F. (19º11’6.50” N, 99º11’41.42” W; 2 312 m asl). The morphology of the larvae is briefly described and a list of previously recorded localities and hosts in Mexico is given. This study is the first record of Physaloptera sp. parasitizing L. montezumae, and also represents the first helminthological record for anurans in this locality, as well as a new locality record for the nematode genus

Dujardinascaris helicina (Nematoda: Ascarididae) parásito de Crocodylus acutus (Reptilia: Crocodylidae) en Puerto Vallarta, Jalisco, México

ResumenEl cocodrilo de río (Crocodylus acutus, Cuvier, 1807) es una especie protegida en México. En este trabajo se han estudiado los contenidos obtenidos por medio de lavados gástricos a 53C. acutus, en las áreas del estero el Salado, estero Boca Negra-Boca de Tomates y en la UMA Reptilario Cipactli, ubicadas en Puerto Vallarta, Jalisco, México, con el fin de conocer la helmintofauna de la especie. Se identificó solamente al nemátodo, Dujardinascaris helicina (Molin, 1860). La mayor prevalencia fue del 74% y la abundancia 3.17 en el área del estero Boca Negra-Boca de Tomates; y la menor prevalencia fue del 12%, con una abundancia de 0.76 en los ejemplares en la UMA Reptilario Cipactli. Suponemos que esta diferencia se debe principalmente al tipo de alimento suministrado a los cocodrilos en cautiverio. En esta investigación se registra por primera vez a D. helicina como parásito de C. acutus en la región.AbstractThe river crocodile (Crocodylus acutus, Cuvier, 1807) is a protected species in Mexico. In this work the stomach contents obtained through gastric lavage of 53 C. acutus from the estuarine systems “El Salado”, “Boca Negra-Boca de Tomates” and from the “UMA (Unidad de Manejo y Conservación de Vida Silvestre” for its meaning in Spanish) Reptilario Cipactli” located in Puerto Vallarta, Jalisco, Mexico were collected to study the helminth fauna of the species. Only Dujardinascaris helicina (Molin, 1860) was identified. The highest prevalence occurred in “Boca Negra-Boca de Tomates” with 74% and an abundance of 3.17, and the lowest in “UMA Reptilario Cipactli” with 12% and an abundance of 0.76. The dissimilarity is assumed to be caused primarily by the different feeding habits between wildlife and captivity raised crocodiles. During this investigation D. helicina is registered for the first time as a parasite for C. acutus in the region

Before the Pandemic Ends: Making Sure This Never Happens Again

Introduction On 30 January 2020, the World Health Organization (WHO) declared a Global Health Emergency of international concern attendant to the emergence and spread of SARS-CoV-2, nearly two months after the first reported emergence of human cases in Wuhan, China. In the subsequent two months, global, national and local health personnel and infrastructures have been overwhelmed, leading to suffering and death for infected people, and the threat of socio-economic instability and potential collapse for humanity as a whole. This shows that our current and traditional mode of coping, anchored in responses after the fact, is not capable of dealing with the crisis of emerging infectious disease. Given all of our technological expertise, why is there an emerging disease crisis, and why are we losing the battle to contain and diminish emerging diseases? Part of the reason is that the prevailing paradigm explaining the biology of pathogen-host associations (coevolution, evolutionary arms races) has assumed that pathogens must evolve new capacities - special mutations – in order to colonize new hosts and produce emergent disease (e.g. Parrish and Kawaoka, 2005). In this erroneous but broadly prevalent view, the evolution of new capacities creates new opportunities for pathogens. Further, given that mutations are both rare and undirected, the highly specialized nature of pathogen-host relationships should produce an evolutionary firewall limiting dissemination; by those definitions, emergences should be rare (for a historical review see Brooks et al., 2019). Pathogens, however, have become far better at finding us than our traditional understanding predicts. We face considerable risk space for pathogens and disease that directly threaten us, our crops and livestock – through expanding interfaces bringing pathogens and hosts into increasing proximity, exacerbated by environmental disruption and urban density, fueled by globalized trade and travel. We need a new paradigm that explains what we are seeing. Additional section headers: The Stockholm Paradigm The DAMA Protocol A Sense of Urgency and Long-Term Commitment Reference

Concepts in Animal Parasitology, Part 3: Endoparasitic Platyhelminths

Part III: Endoparasitic Platyhelminths, chapters 15-47, pages 231-532, in Concepts in Animal Parasitology. 2024. Scott L. Gardner and Sue Ann Gardner, editors. Zea Books, Lincoln, Nebraska, United States; part III doi: 10.32873/unl.dc.ciap073 Platyhelminthes Chapter 15: Introduction to Endoparasitic Platyhelminths (Phylum Platyhelminthes) by Larry S. Roberts, John J. Janovy, Jr., Steve Nadler, and Scott L. Gardner, pages 231-240 Cestoda Chapter 16: Introduction to Cestodes (Class Cestoda) by Scott L. Gardner, pages 241-246 Eucestoda Chapter 17: Introduction to Cyclophyllidea Beneden in Braun, 1900 (Order) by Scott L. Gardner, pages 247-250 Chapter 18: Taenia (Genus) by Sumiya Ganzorig and Scott. L. Gardner, pages 251-261 Chapter 19: Echinococcus (Genus) by Akira Ito and Scott. L. Gardner, pages 262-275 Chapter 20: Proteocephalidae La Rue, 1911 (Family) by Tomáš Scholz and Roman Kuchta, pages 276-282 Chapter 21: Bothriocephalidea Kuchta et al., 2008 (Order) by Jorge Falcón-Ordaz and Luis García-Prieto, pages 283-288 Chapter 22: Diphyllobothriidea Kuchta et al., 2008 (Order): The Broad Tapeworms by Tomáš Scholz and Roman Kuchta, pages 289-296 Chapter 23: Trypanorhyncha Diesing, 1863 (Order) by Francisco Zaragoza-Tapia and Scott Monks, pages 297-305 Chapter 24: Cathetocephalidea Schmidt and Beveridge, 1990 (Order) by Luis García-Prieto, Omar Lagunas-Calvo, Brenda Atziri García-García, and Berenice Adán-Torres, pages 306-309 Chapter 25: Diphyllidea van Beneden in Carus, 1863 (Order) by Luis García-Prieto, Brenda Atziri García-García, Omar Lagunas-Calvo, and Berenice Adán-Torres, pages 310-315 Chapter 26: Lecanicephalidea Hyman, 1951 (Order) by Luis García-Prieto, Berenice Adán-Torres, Omar Lagunas-Calvo, and Brenda Atziri García- García, pages 316-320 Chapter 27: Litobothriidea Dailey, 1969 (Order) by Luis García-Prieto, Berenice Adán-Torres, Brenda Atziri García-García, and Omar Lagunas-Calvo, pages 321-325 Chapter 28: Phyllobothriidea Caira et al., 2014 (Order) by Brenda Atziri García-García, Omar Lagunas-Calvo, Berenice Adán-Torres, and Luis García-Prieto, pages 326-331 Chapter 29: Rhinebothriidea Healy et al., 2009 (Order) by Omar Lagunas-Calvo, Brenda Atziri García-García, Berenice Adán-Torres, and Luis García-Prieto, pages 332-339 Chapter 30: Relics of “Tetraphyllidea” van Beneden, 1850 (Order) by Berenice Adán-Torres, Omar Lagunas-Calvo, Brenda Atziri García-García, and Luis García-Prieto, pages 340-346 Amphilinidea Chapter 31: Amphilinidea Poche 1922 (Order) by Klaus Rohde, pages 347-353 Gyrocotylidea Chapter 32: Gyrocotylidea (Order): The Most Primitive Group of Tapeworms by Willi E. R. Xylander and Klaus Rohde, pages 354-360 Trematoda Aspidogastrea Chapter 33: Aspidogastrea (Subclass) by Klaus Rohde, pages 361-377 Digenea: Diplostomida Chapter 34: Introduction to Diplostomida Olson et al., 2003 (Order) by Lucrecia Acosta Soto, Bernard Fried, and Rafael Toledo, pages 378-393 Chapter 35: Aporocotylidae (Family): Fish Blood Flukes by Russell Q.-Y. Yong, pages 394-401 Digenea: Plagiorchiida Chapter 36: Introduction to Plagiorchiida La Rue, 1957 (Order) by Rafael Toledo, Bernard Fried, and Lucrecia Acosta Soto, pages 402-404 Chapter 37: Bivesiculata Olson et al., 2003 (Suborder): Small, Rare, but Important by Thomas H. Cribb and Scott C. Cutmore, pages 405-408 Chapter 38: Echinostomata La Rue, 1926 (Suborder) by Rafael Toledo, Bernard Fried, and Lucrecia Acosta Soto, pages 409-422 Chapter 39: Haplosplanchnata Olson et al., 2003 (Suborder): Two Hosts with Half the Guts by Daniel C. Huston, pages 423-427 Chapter 40: Hemiurata Skrjabin & Guschanskaja, 1954 (Suborder) by Lucrecia Acosta Soto, Bernard Fried, and Rafael Toledo, pages 428-435 Chapter 41: Monorchiata Olson et al., 2003 (Suborder): Two Families Separated by Salinity by Nicholas Q.-X. Wee, pages 436-442 Chapter 42: Opisthorchis (Genus) compiled from material from the United States Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria by Sue Ann Gardner, pages 443-445 Xiphidiata Chapter 43: Allocreadiidae Looss, 1902 (Family) by Gerardo Pérez-Ponce de León, David Iván Hernández-Mena, and Brenda Solórzano-García, pages 446-459 Chapter 44: Haematoloechidae Odening, 1964 (Family) by Virginia León-Règagnon, pages 460-469 Chapter 45: Lecithodendriidae Lühe, 1901 (Family) by Jeffrey M. Lotz, pages 470-479 Chapter 46: Opecoelidae Ozaki, 1925 (Family): The Richest Trematode Family by Storm B. Martin, pages 480-489 Digenea Summary Chapter 47: Summary of the Digenea (Subclass): Insights and Lessons from a Prominent Parasitologist by Robin M. Overstreet, pages 490-53

Molecular Phylogeny of \u3ci\u3eHaematoloechus\u3c/i\u3e Looss, 1899 (Digenea: Plagiorchiidae), with Emphasis on North American Species

Phylogenetic hypothesis of 23 populations corresponding to 18 species of the digenean Haematoloechus from America, Europe, and Africa, based on ribosomal DNA 28S partial sequences (~890 bp), is presented. Genetic divergence between the in-group and the out-groups ranged from 9.7 to 14.5% and within the in-group, from 0.9 to 12.2%. Eight most parsimonious trees 569 steps long were obtained, with a consistency index of 72%. Groups in the tree are not congruent with those in previous classification schemes of species in the genus, based on a small number of morphological characters. For this subset of Haematoloechus,/i\u3e species, plesiomorphic hosts are species of Rana, with two colonizations to other amphibian groups. African species appear to have diverged after the separation of Gondwana and Laurasia. Therefore, South American species should appear as the closest relatives of African species when included in the analysis. The evidence presented suggests an ancestral wide distribution of North American representatives of the group, followed by successive contraction, amplification, and fragmentation of ranges and speciation events as a result of the intense volcanic activity in the central part of Mexico since the late Tertiary, the drying climate of western and central United States and northwestern Mexico from the early Eocene to the Pleistocene, and the glaciation during the Pleistocene

Haematoloechus mexicanus León-Règagnon & Topan 2018, n. sp.

Haematoloechus mexicanus n. sp. (Figs. 10 & 11) Type host: Montezuma leopard frog Rana montezumae (=Northern leopard frog R. pipiens Schreber and R. montezumae of Caballero 1941). Type locality: Ciénaga de Lerma, Estado de Mexico, Mexico. Site of infection: Lungs Holotype: CNHE 10489 Paratypes: CNHE 10490, 10491, 10492. Etymology: Species name refers to Estado de Mexico, the province of the type locality. Other hosts and localities: Mexico: Montezuma leopard frog Rana montezumae, Xochimilco, Mexico City (Caballero, 1941, as H. medioplexus); Patzcuaro leopard frog R. dunni, Pátzcuaro, Michoacán (León-Règagnon et al. 1999, as H. coloradensis); Transverse Volcanic leopard frog R. neovolcanica, Cointzio, Michoacán (this study). Description: Based on 17 mature specimens: Body slender, with thinner anterior region; 4.8–8.3 (7.0) mm long, 0.7–1.3 (1.0) mm of maximum width at testicular region. Tegument covered with abundant thin spines, easily lost during fixation; 7.5–12.5 (9.8) long. Oral sucker subterminal, round, 203–350 (284) long, 180–380 (278) wide. Pharynx oval, 140–280 (206) long, 122–220 (183) wide; oral sucker/pharynx ratio 1: 0.74–0.90 (0.83). Anterior border of pharynx and esophagus surrounded by gland cells. Esophagus 41–200 (129) long. Ceca bifurcated at 390–770 (609) from anterior extremity. Ceca terminate blindly near posterior extremity. Ventral sucker small, weakly developed, frequently obscured by uterus, 52–125 (82) long, 57–130 (84) wide, at 1.5–3.0 (2.4) mm (31%– 41% (37%) of BL) from anterior extremity. Sucker length ratio 1:0.28–0.38 (0.33). Testes 2, elliptical, elongate, oblique, posterior to ovary; distance between ovary and anterior testis 350–825 (548). Anterior testis opposite to ovary, 365–1,080 (778) long, 243–600 (451) wide. Posterior testis 422–1200 (863) long, 260–830 (495) wide. Cirrus sac reaches anterior border of ventral sucker, mostly obscured by ascending uterus; internal seminal vesicle, elongate, slightly coiled. Ejaculatory duct weakly muscular, 150–160 (155) long, surrounded by prostatic gland cells. Ovary kidney shaped, lobed, 320–840 (623) long, 162–500 (342) wide; at 1.8–4.3 (2.8) mm (35%–57% (40%) of BL) from anterior extremity. Seminal receptacle posterior, partially overlapped with ovary; 300–1000 (644) long, 250–590 (410) wide. Mehlis gland dorsal to seminal receptacle. Laurer’s canal not observed. Vitellaria in clusters of oval, well defined follicles, distributed laterally, dorsally invade space between ceca in anterior region of ovary and sometimes in post-testicular region. Anterior limit of distribution 982–3200 (1766) (19%–49% (25%) of BL) from anterior end. Follicles extend asymmetrically, to anterior region of posterior testis on ovarian side of body, and halfway between posterior testis and posterior end of body on side opposite to ovary. Uterine loops fill intra- and extracecal space, partially overlap testes and ovary. Descending part of uterus form several diagonal loops that frequently bend anteriorly or posteriorly and form short longitudinal extracecal loops on ovarian side of body. Uterus forms two longitudinal uterine loops on each side of posterior end of body that reach halfway between posterior end and posterior testis; one loop is frequently shorter. Ascending part of uterus forms diagonal loops on side opposite to ovary, frequently bends anteriorly or posteriorly to form longitudinal extracecal loops. Descending and ascending parts of uterus in two lateral fields rarely invade each other. Distal uterus fills intracecal preovarian region with diagonal loops. Genital pore median, ventral to middle region of pharynx. Eggs dark brown, 22–26 (24) long, 14–20 (17) wide. Excretory vesicle not observed. Excretory pore terminal. Remarks: Haematoloechus mexicanus n. sp. resembles those species of the genus possessing short longitudinal or diagonal uterine loops not reaching the posterior testis, namely H. aubriae, H. caballeroi, H. danbrooksi, H. fuelleborni, H. humboldtensis, H. illimis, H. kernensis, H. occidentalis n. sp., H. pukinensis, and H. veracruzanus n. sp. It also resembles those species with a ventral sucker less than half the size of the oral sucker, namely H. combesi Batchvarov & Bourgat, 1974, H. danbrooksi, H. darcheni Combes & Knoepffler, 1967, H. floedae, H. leonensis (Williams & Coker, 1967), H. medioplexus, H. meridionalis, H. nicolasi, H. ocellati Gassmann, 1975 and H. parviplexus (Table 2). This new species differs from H. caballeroi, H. fuelleborni, H. humboldtensis, H. illimis, H. kernensis, H. occidentalis n. sp., H. pukinensis, and H. veracruzanus n. sp. in the size of the ventral sucker compared to the oral sucker, which is smaller in H. mexicanus n. sp. (1: 0.5–1.0 in the other species vs 1: 0.33 in H. mexicanus n. sp.), and it differs from H. aubriae in the presence of ventral sucker, which is absent in that species. It also differs from H. aubriae, H. caballeroi, H. fuelleborni, H. humboldtensis, H. kernensis, H. occidentalis n. sp., H. pukinensis, and H. veracruzanus n. sp. in the shape of ovary and testes, which are oval in those species, while in H. mexicanus n. sp. the ovary is lobed and testes are elliptical or elongate. Haematoloechus mexicanus n. sp. differs from H. combesi, H. darcheni, H. floedae, H. leonensis, H. medioplexus, H. meridionalis, H. nicolasi, H. ocellati and H. parviplexus in the arrangement of the uterine loops. Haematoloechus medioplexus and H. meridionalis lack uterine longitudinal loops (Stafford, 1902; León-Regagnon et al. 2001), in H. combesi, H. floedae and H. leonensis they reach the level of the ovary (Williams & Coker 1967; Batchvarov & Bourgat 1974; León-Règagnon et al. 2005), in H. darcheni and H. ocellati they reach the level of the anterior testis (Combes & Knoepffler 1967; Gassmann 1975), in H. nicolasi and H. parviplexus they reach the level of the posterior testis (Irwin 1929; León-Règagnon 2017), while in H. mexicanus n. sp. they reach halfway between the posterior testis and the posterior end. In this new species there are frequently several short longitudinal uterine loops in the posttesticular region and at the level of testes, which are absent in the other species. Haematoloechus mexicanus n. sp. most closely resembles H. danbrooksi in the size of the ventral sucker and the presence of short diagonal or longitudinal uterine loops in the posterior end of body, but differs from that species in the shape of the ovary, which is oval or slightly bi-lobed in some specimens (León-Règagnon & Paredes-Calderón 2002) and deeply lobed in H. mexicanus n. sp. The arrangement of the uterus also differentiates these two species; while in H. danbrooksi the descending and ascending uterine loops often invade both sides of the body, in H. mexicanus n. sp. descending and ascending uterine loops form two lateral fields and rarely invade one another. Finally, the longitudinal uterine loops in the posterior end of the body are shorter in H. danbrooksi .Published as part of León-Règagnon, Virginia & Topan, Janet, 2018, Taxonomic revision of species of Haematoloechus Looss, 1899 (Digenea: Plagiorchioidea), with molecular phylogenetic analysis and the description of three new species from Mexico, pp. 251-302 in Zootaxa 4526 (3) on pages 269-272, DOI: 10.11646/zootaxa.4526.3.1, http://zenodo.org/record/261161

Haematoloechus caballeroi Skrjabin & Antipin 1962

Haematoloechus caballeroi Skrjabin & Antipin, 1962 (Figs. 4 & 5) Type host: Tlaloc´s leopard frog Rana tlaloci Hillis & Frost recorded as Montezuma leopard frog Rana montezumae (Caballero, 1942b; Skrjabin & Antipin, 1962). Type locality: Xochimilco, Mexico City, Mexico (Caballero, 1942b; Skrjabin & Antipin, 1962). Site of infection: lungs. Neotype: CNHE 10457. Paratypes: CNHE 1428, 1551, 1552, 3376–3379, 3395, 3397, 3399, 3794, 4661, 10458–10460. Other hosts and localities: Montezuma leopard frog R. montezumae, Zempoala, Morelos (CNHE 10464), Patzcuaro leopard frog R. dunni Zweifel, Pátzcuaro, Michoacán (CNHE 10465); R. dunni, Zacapu, Michoacán (CNHE 10463). Other records: Mexico: Tlaloc´s leopard frog R. tlaloci, Xochimilco, Mexico City (Caballero &Sokoloff 1934 as H. complexus); Montezuma leopard frog R. montezumae, Ciénaga de Lerma, Mexico State (León- Règagnon 1992 as H. complexus; Lamothe et al. 1997 as H. coloradensis Cort, 1915; León-Règagnon et al. 1999 as H. complexus; Pérez-Ponce de León et al. 2000 as H. coloradensis and H. complexus); big-footed leopard frog R. megapoda, Cointzio Springs, Michoacán (Pérez-Ponce de León et al. 2000 as H. complexus); Transverse Volcanic leopard frog R. neovolcanica, Cointzio Springs, Michoacán (Pérez-Ponce de León et al. 2000 as H. complexus); Patzcuaro leopard frog R. dunni, Pátzcuaro, Michoacán (García-Altamirano et al. 1993; Pulido–Flores 1994; Pérez-Ponce de León et al. 2000 as H. coloradensis); Lerma Lake salamander Ambystoma lermaense, Ciénaga de Lerma, Mexico State (Pérez-Ponce de León et al. 2000 as H. complexus; Mata-López et al. 2002 as H. complexus). Redescription: Based on 33 mature specimens. Body elongate, with slender anterior region; 2.8–6.6 (5.0) mm long, 0.82–1.88 (1.27) mm of maximum width at testicular region. Tegument covered with thin spines that are larger and more abundant in anterior region; spines easily lost during fixation and staining procedures; 8–16 (13) long. Oral sucker subterminal, round, 243–487 (355) long, 260–511 (387) wide. Pharynx oval, 146–398 (255) long, 130–300 (206) wide; oral sucker/pharynx ratio 1: 0.41–0.86 (0.66). Pharynx and anterior region of esophagus surrounded by gland cells. Esophagus 24–162 (65) long, sometimes obscured by uterus. Ceca bifurcated at 414– 844 (643) from anterior extremity. Ceca terminate blindly near posterior extremity. Ventral sucker round, 219–438 (313) long, 203–430 (311) wide, at 0.98–2.7 (1.9) mm (30%–47% (37.6%) of BL) from anterior extremity. Oral sucker: ventral sucker length ratio 1: 0.53–1.0 (0.81). Testes 2, oval, slightly lobed in some specimens, oblique, inmmediately posterior to ovary. Anterior testis opposite to ovary, 219–795 (477) long, 170–682 (360) wide. Posterior testis 203–852 (557) long, 203–771 (396) wide. Cirrus sac reach anterior border of ventral sucker, mostly obscured by ascending uterus; internal seminal vesicle, elongate, slightly coiled. Ejaculatory duct strongly muscular, 190–200 (195) long, surrounded by prostatic gland cells. Ovary oval, 243–665 (414) long, 203–763 (313) wide; at 1.1–2.9 (2.1) mm (33%–51% (42%) of BL) from anterior extremity. Seminal receptacle adjacent partially overlapped with ovary; 203–730 (412) long, 138–568 (300) wide. Mehlis gland dorsal to seminal receptacle. Laurer’s canal not observed. Vitellaria in clusters overlapped with each other, distributed laterally, dorsally invade space between ceca in their anterior limit and in post-testicular region. Anterior limit of distribution 390–1607 (1055) (6.5%–28% (21%) of BL) from anterior end. Follicles extend to halfway between posterior testis and posterior end; in some specimens they extend to level of posterior testis on ovarian side of body, and more posteriorly on side opposite to ovary. Descending part of uterus form transverse and diagonal loops on ovarian side of body, partially overlapped with testis, filling intra- and extracecal space towards posterior end of body. Ascending uterus form one or two short diagonal loops oriented anteriorly on each side of body, and continues with transverse or diagonal loops that occasionally invade both sides of body, not totally overlapped with testes or ovary, and fill with transverse loops entire preovarian region. Genital pore median, ventral to pharynx. Eggs dark brown, 31–40 (36) long, 17–23 (20) wide. Excretory vesicle not observed. Excretory pore terminal. Remarks: In their revision of the family Plagiorchiidae Lühe, 1901, Skrjabin & Antipin (1962) described Haematoloechus caballeroi based on a specimen that Caballero (1942b) collected from Tlaloc´s leopard frog R. tlaloci in Xochimilco, Mexico, and was originally identified as H. complexus. This description was based on a single specimen, and was not recognized by any later author; all subsequent records of that morphotype from Mexico were assigned to H. complexus or H. coloradensis. Recent molecular and morphological evidence has shown that H. complexus sensu stricto does not occur in Mexico, but that there is a complex of species closely related to H. complexus, most undescribed (León-Règagnon & Brooks 2003; Bolek & Janovy 2007a; León- Règagnon 2010; León-Règagnon & Romero–Mayén 2017). The present species is one of those (GenBank AF532138, León-Règagnon & Brooks 2003). Haematoloechus caballeroi differs from most other species in the genus, but resembles the following 19 species by lacking longitudinal uterine loops that reach the posterior testis: H. arequipensis Ibáñez & Córdoba, 1979, H. aubriae Bourgat, Roure & Kulo, 1996, H. coloradensis, H. complexus, H. confusus Ingles, 1932, H. danbrooksi, H. dollfusinum (Odening, 1958), H. elongatus Caballero & Sokoloff, 1934, H. fuelleborni (Travassos & Darriba, 1930), H. humboldtensis, H. illimis, H. kernensis Ingles, 1932, H. longicollum, H. medioplexus, H. meridionalis, H. oxyorchis Ingles, 1932, H. parcivitellarius Caballero, 1942, H. pukinensis Ibáñez & Córdoba, 1979, and H. pulcher. It differs from H. aubriae, H. danbrooksi, H. medioplexus, and H. meridionalis in the large size of the ventral sucker compared to the oral sucker, which is less than one third in those four species vs more than half in H. caballeroi (Table 2) (Stafford 1902; Bourgat et al. 1996; León-Règagnon et al. 2001; León- Règagnon & Paredes-Calderón 2002). Haematoloechus coloradensis, H. confusus, and H. oxyorchis differ from H. caballeroi in the arrangement of the uterine loops, which are strictly intercecal in those species (Cort 1915; Ingles 1932; Bolek & Janovy 2007a), while they invade the extracecal region in H. caballeroi. Haematoloechus caballeroi differs from H. arequipensis in having oval rather than lobed testes (Ibañez & Córdoba 1979). It differs from H. illimis and H. dollfusinum in the shape of the ovary, which is lobed in those species (Caballero 1942a) and oval in H. caballeroi. The presence of diagonal uterine loops directed anteriorly at the posterior end of the body differentiates H. caballeroi from H. humboldtensis, H. longicollum, H. parcivitellarius, and H. pulcher, in which the diagonal uterine loops are either absent or directed posteriorly (Caballero 1942b; Bravo–Hollis 1943; Zamparo et al. 2011; León-Règagnon & Romero–Mayén 2017). Haematoloechus caballeroi most closely resembles H. complexus, H. elongatus, H. fuelleborni, H. kernensis and H. pukinensis. It differs from H. fuelleborni, H. complexus and H. elongatus in having a larger pharynx and ventral sucker compared to the oral sucker (1:0.45, 1:0.56, 1:51 & 1:0.5, 1:0.71, 1:0.70 respectively vs 1:0.66 & 1: 0.81 in H. caballeroi) (Travassos & Darriba 1930; Caballero & Sokoloff 1934; Bolek & Janovy 2007a). It also differs from H. fuelleborni in the distribution of the vitellaria; while they are limited to two groups, one anterior to the ventral sucker and other posterior to the testes in the South American species, they are distributed continuously from the anterior region of the ventral sucker to the posterior region of the testes in H. caballeroi. It also differs from H. complexus in the distribution of the vitellaria which are distributed asymmetrically in that species, being more restricted to the ovarian side of the body (Bolek & Janovy 2007a), while in H. caballeroi they reach the posterior region of the testes on both sides of the body. In addition to the differing size of the ventral sucker and pharynx, H. elongatus differs from H. caballeroi in body size, which is much larger in that species (9.5 mm vs 5.1 mm) than in H. caballeroi. Haematoloechus caballeroi differs from H. kernensis in the size of the ventral sucker compared with the oral sucker, which is larger in that species (1:1, vs 1: 0.82 in H. caballeroi). It also differs from H. kernensis in the distribution of the vitellaria, which do not invade the intercecal region in the post-testicular region in that species, and in the arrangement of the uterus, which forms a few diagonal loops in the pre-acetabular and post-testicular region in H. kernensis, while it is filled with transverse and diagonal loops in both areas in H. caballeroi (Ingles 1932). Haematoloechus caballeroi differs from H. pukinensis in the arrangement of the uterine loops; while in H. pukinensis the ascending part of the uterus forms a few transverse loops in the pre-acetabular region (Ibáñez & Córdoba 1979), in H. caballeroi the ascending uterus entirely fills the pre-acetabular region. The distribution of the vitellaria is also different in H. pukinensis, being more restricted in the ovarian side of the body in that species. ......continued on the next page......continued on the next page H = Hasegawa et al., 2013. L = León-Règagnon 2010. LB = León-Règagnon & Brooks 2003. LGA = León-Règagnon et al. 2005. RLP = Razo-Mendívil et al. 2004, 2006. T = Tkach et al. 2000. Z = Zikmundova et al. 2014. 1 originally recorded as H. coloradensis. 2 originally recorded as H. cf. complexus. 3 originally recorded as H. varioplexus.Published as part of León-Règagnon, Virginia & Topan, Janet, 2018, Taxonomic revision of species of Haematoloechus Looss, 1899 (Digenea: Plagiorchioidea), with molecular phylogenetic analysis and the description of three new species from Mexico, pp. 251-302 in Zootaxa 4526 (3) on pages 254-262, DOI: 10.11646/zootaxa.4526.3.1, http://zenodo.org/record/261161

Haematoloechus veracruzanus León-Règagnon & Topan 2018, n. sp.

Haematoloechus veracruzanus n. sp. (Figs. 8 & 9) Type host: common marsh frog Rana vaillanti. Type locality: Laguna Escondida, Los Tuxtlas, Veracruz, Mexico. Site of infection: lungs Holotype: CNHE 4087 Paratypes: CNHE 4086, 4089, 4090, 10515. Other hosts and localities: common marsh frog R. vaillanti, Los Tuxtlas, Veracruz (Paredes-Calderón et al. 2004 as H. complexus); Catemaco, Veracruz (GenBank MG647801, MG647802, MG672439); Rio Grande leopard frog R. berlandieri , Laguna Higueras, Nuevo León (León-Règagnon et al. 2005, as H. complexus), Huauchinango, Puebla (León-Régagnon 2003, as H. complexus CNHE 10517), Rana sp., Tierra Quemada (CNHE 10518) and Rancho el Borbotón (CNHE 10519), San Luis Potosí, Mexico. Etymology: Species name refers to Veracruz, the state in Mexico where the type locality is located. Description: Based on 11 mature specimens. Body elongate, with slender anterior region; 3.5–5.2 (4.3) mm long, 0.80–1.64 (1.17) mm of maximum width at testicular region. Tegument aspinose, even in live specimens. Oral sucker subterminal, round, 203–365 (310) long, 252–409 (318) wide. Pharynx oval, 97–195 (154) long, 105– 170 (145) wide; oral sucker: pharynx ratio 1: 0.38–0.56 (0.48). Pharynx and anterior region of esophagus surrounded by abundant gland cells. Esophagus 65–122 (96) long, sometimes obscured by uterus. Ceca bifurcated at 381–649 (496) from anterior extremity. Ceca terminate blindly near posterior extremity. Ventral sucker round, 178–292 (245) long, 203–340 (265) wide, at 0.9–1.84 (1.4) mm (26%–38% (33%) of BL) from anterior extremity. Sucker length ratio 1: 0.64–0.94 (0.84). Testes 2, oval, oblique to almost tandem, inmmediately posterior to ovary. Anterior testis opposite to ovary, 308–771 (476) long, 292–674 (415) wide. Posterior testis 446–795 (604) long, 284–771 (433) wide. Cirrus sac reaches anterior border of ventral sucker, mostly obscured by ascending uterus; internal seminal vesicle, elongate, slightly coiled. Ejaculatory duct weakly muscular, 260–330 (295) long, surrounded by prostatic gland cells. Ovary oval, 349–576 (449) long, 227–608 (335) wide; at 0.92–2.1 (1.6) mm (26%–42% (37%) of BL) from anterior extremity. Seminal receptacle adjacent and partially overlaps ovary; 349– 771 (548) long, 341–649 (429) wide. Mehlis gland dorsal to seminal receptacle. Laurer’s canal not observed. Vitellaria in clusters overlapped with each other, distributed laterally, dorsally invade space between ceca in their anterior limit and in post-testicular region. Anterior limit of distribution 471–1000 (662) (10%–23% (15%) of BL) from anterior end. Follicles extend asymmetrically, to level of posterior testis on ovarian side of body, and halfway between posterior testis and posterior end on side opposite to ovary. Uterine loops fill intra- and extracecal space, partially overlapped with testes and ovary. Descending part of uterus form several diagonal loops that frequently bend anteriorly or posteriorly and form short longitudinal extracecal loops. Uterus forms two diagonal uterine loops oriented anteriorly on each side of posterior end of body, sometimes reaches halfway between posterior end and posterior testis. Ascending part of uterus form transverse or diagonal loops on side opposite to ovary, they frequently invade ovarian side and bend anteriorly or posteriorly to form short longitudinal extracecal loops. Distal uterus fills entire preovarian region with diagonal loops. Genital pore median, ventral to anterior region of pharynx. Eggs dark brown, 34–40 (37) long, 18–23 (20) wide. Excretory vesicle not observed. Excretory pore terminal. Remarks: Haematoloechus veracruzanus n. sp. resembles H. arequipensis, H. caballeroi, H. complexus, H. danbrooksi, H. dollfusinum, H. elongatus, H. fuelleborni, H. humboldtensis, H. illimis, H. kernensis, H. longicollum, H. medioplexus, H. meridionalis, H. occidentalis n. sp., H. parcivitellarius, H. pukinensis, and H. pulcher and differs from other American species in the genus by having uterine loops invading the extracecal area, and by lacking longitudinal uterine loops reaching at least the level of the posterior testis. It differs from H. danbrooksi, H. medioplexus, and H. meridionalis in the size of the ventral sucker compared to the oral sucker, which is less than one third in those four species vs more than half in H. veracruzanus n. sp. (Table 2) (Stafford 1902; León-Règagnon et al. 2001; León-Règagnon & Paredes-Calderón 2002). Haematoloechus veracruzanus n. sp. differs from H. arequipensis in having oval rather than lobed testes (Ibañez & Córdoba 1979), and differs from H. illimis and H. dollfusinum in the shape of the ovary, which is lobed in those species (Caballero 1942a) and oval in H. veracruzanus. The presence of diagonal uterine loops directed anteriorly at the posterior end of the body differentiates H. veracruzanus n. sp. from H. humboldtensis, H. longicollum, H. parcivitellarius, and H. pulcher, in which the diagonal uterine loops are either absent or directed posteriorly (Caballero 1942b; Bravo–Hollis 1943; Zamparo et al. 2011; León-Règagnon & Romero–Mayén 2017). Haematoloechus veracruzanus n. sp. differs from H. fuelleborni, in having a larger ventral sucker compared to the oral sucker (1:0.5 vs 1: 0.84 in H. veracruzanus n. sp.), and in the distribution of the vitellaria; while they are limited to two groups, one anterior to the ventral sucker and other posterior to the testes in the South American species, they are distributed continuously extending asymmetrically, from the region anterior to the ventral sucker to the level of the posterior testis on the ovarian side of the body, and halfway between the posterior testis and the posterior end on the side opposite to the ovary in H. veracruzanus n. sp. (Travassos & Darriba 1930). It differs from H. complexus and H. elongatus in the arrangement of the uterine loops. While in H. complexus and H. elongatus the uterine loops are transverse in the post-acetabular region (Caballero & Sokoloff 1934; Bolek & Janovy 2007a), in H. veracruzanus n. sp. the uterine loops are transverse or diagonal often bending to form short longitudinal loops that can be oriented anteriorly or posteriorly. Haematoloechus elongatus is also much larger in body size than H. veracruzanus n. sp. (9.5 mm vs 4.3 mm). Haematoloechus veracruzanus n. sp. differs from H. occidentalis n. sp. in the arrangement of the uterine loops; while the descending and ascending loops form two lateral fields in the post-testicular region in H. occidentalis n. sp., the ascending uterine loops frequently invade both sides of the body in H. veracruzanus n. sp. (Figs. 6 & 8). Haematoloechus veracruzanus n. sp. differs from H. kernensis in the arrangement of the uterus, which forms a few diagonal loops in the pre-acetabular and post-testicular region in that species, while fills with transverse or diagonal loops in both areas in H. veracruzanus n. sp., and in the distribution of the vitellaria, which do not invade the intercecal region in the post-testicular area in H. kernensis (Ingles 1932). The new species also differs from H. pukinensis in the arrangement of the uterine loops; while in H. pukinensis the ascending part of the uterus forms a few transverse loops in the pre-acetabular region (Ibáñez & Córdoba 1979), in H. veracruzanus n. sp. the ascending uterus entirely fills the pre-acetabular region. Haematoloechus veracruzanus n. sp. most closely resembles H. caballeroi, but the two species can be differentiated by the arrangement of the uterus. While in H. caballeroi, the descending and ascending uterus form transverse loops that sometimes become diagonal and are oriented anteriorly in the extracecal region, in H. veracruzanus n. sp. the uterine loops are transverse or diagonal, frequently bending to form short longitudinal loops in the extracecal region that can be oriented anteriorly or posteriorly; also, the ejaculatory duct in H. caballeroi is strongly muscular while it is weakly muscular in H. veracruzanus n. sp. (Figs. 5 & 9). Haematoloechus veracruzanus n. sp. is another species that was differentiated using DNA sequences (León- Règagnon & Brooks 2003, Genbank AF531857; León-Règagnon 2010, GenBank HQ141684 (Ha15), HQ141701 (Ha51)) and is included in the "complexus group".Published as part of León-Règagnon, Virginia & Topan, Janet, 2018, Taxonomic revision of species of Haematoloechus Looss, 1899 (Digenea: Plagiorchioidea), with molecular phylogenetic analysis and the description of three new species from Mexico, pp. 251-302 in Zootaxa 4526 (3) on pages 265-269, DOI: 10.11646/zootaxa.4526.3.1, http://zenodo.org/record/261161