La parasitofauna de Laurus dominicanus en el Parque Nacional Nahuel Huapi

La parasitofauna de Larus dominicanus (gaviota cocinera) en Sudamérica, incluye numerosas especies de digeneos, cestodes, nematodes y acantocéfalos. Las familias de digeneos registradas hasta la fecha en ambientes de agua dulce de Argentina, que utilizan a L. dominicanus cómo hospedador definitivo son: Microphallidae, Heterophyidae, Echinostomatidae, Diplostomidae y Schistosomatidae. El objetivo de este trabajo fue describir la comunidad de helmintos de la población de gaviotas cocineras en el lago Nahuel Huapi, para ello se describieron los digeneos adultos encontrados en L. dominicanus, los estadios larvales encontrados en posibles hospedadores intermediarios registrados en la dieta. Por último, se describe la composición y la estructura de las comunidades de helmintos. Se capturaron 42 gaviotas en las 4 estaciones de los años 2013 y 2014, con trampas cebadas en el Parque Nacional Nahuel Huapi. Las gaviotas fueron trasladadas inmediatamente al Laboratorio donde se revisaron las vísceras. Entre los resultados podemos señalar que se registraron 17 especies parásitas, registrándose 11 especies de digeneos, 3 de cestodes y 3 de nematodes; algunas de ambientes dulceacuícolas y otras típicamente marinas. De estos registros 4 corresponderían a nuevas especies (Levinseniella sp., Cryptocotyle dominicana, Gymnophallus sp., Himasthla sp.), 5 a especies ya descriptas en Patagonia (Maritrema patagonica, Tylodelphys cf. brevis, Stephanoprora uruguayense, Echinostoma chloephagae y Marinabilharzia patagonense). Los digeneos de las gaviotas cocinera del Parque Nacional utilizarían a los moluscos Chilina gibbosa y Heleobia hatcheri como hospedadores intermediarios primarios. Los peces Galaxias maculatus y Galaxias platei y cangrejos del género Aegla y en menor medida los gastrópodos C. gibbosa serían los hospedadores secundarios, conformando una red de transmisión relativamente simple en comparación de la estructura trófica marina. Las gaviotas presentaron en sus contenidos estomacales una mayor proporción de desechos antrópicos, los que fueron seguidos por insectos, crustáceos y en menor medida por peces. En la población de gaviotas de agua dulce comparadas con las poblaciones de ambientes marinos, la menor variedad de ítems alimentarios de origen animal, en relación a los desechos antrópicos, se refleja en una menor riqueza y abundancia de especies parásitas. La proporción de gaviotas infectadas por al menos una especie fue alta (90,5%). Se recuperaron un total de 1499 helmintos, con un promedio de 39,4 especímenes por gaviota infectada. Ninguna especie alcanzó el 70 % de prevalencia, por lo que ninguna pudo clasificarse como central, siete se clasificaron como secundarias y las restantes como especies satélite. La comunidad muestra una diversidad intermedia (2,57) y una equitatividad relativamente alta (0,64). Según los valores de dominancia e índice de importancia, la comunidad componente estuvo dominada por tres especies de digeneos, C. dominicana, E. chloephagae y Echinoparyphium sp. Al clasificar las especies en función del índice de importancia la comunidad de gaviotas del lago Nahuel Huapi presenta un 37,5% (6/16) de especies componentes, 50% de acompañantes (50%) y 6,3% de accidentales y de inmigrantes no exitosas. En cuanto a la variación estacional se registró la mayor riqueza en otoño (16 especies) y la menor en primavera (8 especies). En todas las estaciones se registraron especies marinas como Himasthla sp., Diplostomum dominicanum, Gymnophallus sp. y Marinabilharzia patagonense. La máxima riqueza observada en otoño podría deberse a que en esta estación los niveles del agua están en su punto mínimo, por lo que las comunidades de organismos acuáticos como los cangrejos y los caracoles que habitan la zona litoral y que son hospedadores intermediarios se encuentran más expuestos a la depredación por las gaviotas. La presencia de especies de origen marino es un indicador de que gaviotas marinas estarían movilizándose hacia la zona cordillerana, ya sea de la costa atlántica o pacífica.The parasite-fauna of Larus dominicanus (kelp gull) in South America includes numerous species of digeneans, cestodes, nematodes and acanthocephalans. The digenean families recorded to date, in freshwater environments of Argentina, which use L. dominicanus as the definitive host are: Microphallidae, Diplostomidae, Echinostomatidae, Heterophyidae, and Schistosomatidae. The objective of this work was to describe the helminth community of the kelp gull population in Lake Nahuel Huapi, for which the adult digeneans found in L. dominicanus, the larval stages found in possible intermediate hosts recorded from the diet were sampled and the larval stages found, were described. Finally, the composition and structure of the helminth communities is analyzed. A total of 42 kelp gulls were captured in the 4 seasons of the years 2013 and 2014, with baited traps in the Nahuel Huapi National Park. The kelp gulls were transported to the Laboratory where the viscera were examined. A total of 17 parasite species were registered, corresponding to 11 species of digeneans, 3 of cestodes, and 3 of nematodes; some with freshwater life cycles, and others with typically marine ones. Of these records, 4 correspond to new species (Levinseniella sp., Cryptocotyle dominicana n. sp., Gymnophallus sp., Himasthla sp.), 5 to species already described in Patagonia (Maritrema patagonica, Tylodelphys cf. brevis, Stephanoprora uruguayense, Echinostoma chloephagae, and Marinabilharzia patagonense). The digeneans of kelp gulls in the National Park would use the mollusks Chilina gibossa and Heleobia hatcheri as primary intermediate hosts. The fish Galaxias maculatus and Galaxias platei, the crabs of the genus Aegla and to a lesser extent, the gastropod C. gibbosa would be the secondary hosts for many of the parasite species, establishing a relatively simple transmission network compared to the marine trophic structure. Kelp gulls presented a highest proportion of anthropic waste in their stomach contents, followed by insects, crustaceans, and, to a lesser extent, fish. In the freshwater kelp gull population compared to marine populations, the lower variety of food items of animal origin, in relation to anthropogenic waste, is reflected in a lower richness and abundance of parasitic species. The proportion of kelp gulls infected by at least one species was high (90.5%). A total of 1,499 helminths were recovered, with an average of 39 worms per infected gull. No species reached 70% prevalence so that none could be classified as central, seven were classified as secondary and the rest as satellite species. The community shows intermediate diversity (2.57) and relatively high evenness (0.64). According to the values of dominance and importance index, the component community was dominated by three species of digeneans, C. dominicana, E. chloephagae and Echinoparyphium sp. To classify the species according to the importance index, the community of kelp gulls of Lake Nahuel Huapi presented 37.5% (6/16) of component species, 50% of companion species (50%), and 6.3% of accidental and unsuccessful immigrants. Regarding seasonal variation, the highest richness was recorded in autumn (16 species) and the lowest in spring (8 species). Marine species were recorded at all seasons, including Diplostomum dominicanum, M. patagonense, Himasthla sp., Gymnophallus sp. and Marinabilharzia patagonense. The maximum richness observed in autumn could be due to the low water level of lakes in this season, which is at their minimum point, so the communities of aquatic organisms such as crabs and snails that inhabit the littoral zone, which are intermediate hosts for many parasites, are more exposed to predation by kelp gulls. The presence of marine origin species is an indicator that kelp gulls would be moving towards the Andes, either from the Atlantic or Pacific coasts.Fil: Casalins, Laura Martha. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina

El contexto como eje fundamental para el desarrollo de aprendizajes significativos en el área de matemáticas

This research is developed with the objective of proposing didactic strategies that, through the context, contribute to the development of significant learning in the area of mathematics of second-grade students from the María Auxiliadora educational institution in the municipality of Sabanagrande / Atlántico, Colombia. . This project arose due to the need to strengthen the mathematical learning of students through the formation of meaningful learning; Due to the problem situations presented by students in this area, from demotivation, disinterest and distraction in the teaching-learning processes, marked by a traditional education. In this sense, the methodology of the project has been developed under a complementary paradigm, in which the diverse approaches, beliefs and views of people's thoughts are integrated. In addition, it has some scopes of an exploratorydescriptive type which allow to analyze the problem presented and collect information on said analysis data; Finally, it is presented with a mixed research approach that allows to analyze the variables of the qualitative and quantitative data and with a type of DEXPLOS design which allows to explore and describe the phenomenon presented. The collection of information was carried out through an interview with teachers and specialists and a survey of the students of the institution to know their tastes and inclinations and aspects of their daily life as well as the teachers' perceptions regarding teaching. mathematics and meaningful learning, formed throughout his career. After this analysis, various conclusions are drawn about didactics and methodologies that manage to favor mathematical learning and, it is recognized that the use of context, everyday situations, and everything they represent contribute to the formation of meaningful learning for the student. , allowing him a broader vision regarding what this problem area tends to be, broadening his participation and evaluating his experiences and ideas in a mathematics class.La presente investigación se desarrolla con el objetivo de proponer estrategias didácticas que a través del contexto contribuyan al desarrollo de los aprendizajes significativos en el área de matemáticas de los estudiantes de segundo grado de la institución educativa María Auxiliadora en el municipio de Sabanagrande/Atlántico, Colombia. Este proyecto surgió debido a la necesidad de fortalecer los aprendizajes matemáticos de los estudiantes a través de la formación de aprendizajes significativos; debido a las situaciones problémicas presentadas por los estudiantes en esta área, desde desmotivación, desinterés y distracción en los procesos de enseñanza aprendizaje, marcado por una educación tradicional. En este sentido, la metodología del proyecto se ha desarrollado bajo un paradigma de tipo complementario, en el que se logran integrar los diversos enfoques, creencias y visiones de pensamiento de las personas. Además, posee unos alcances de tipo exploratorio - descriptivo los cuales permiten analizar la problemática presentada y recoger información sobre dichos datos de análisis; finalmente se presenta con un enfoque de investigación mixto que permite analizar las variables de los datos cualitativos y cuantitativos y con un tipo de diseño DEXPLOS el cual permite explorar y describir el fenómeno presentado. La recolección de la información fue realizada a través de una entrevista a docentes y especialistas y una encuesta a los estudiantes de la institución para conocer los gustos e inclinaciones de ellos y aspectos de su vida diaria además de las percepciones de los docentes frente a la enseñanza matemática y el aprendizaje significativo, formadas a lo largo de su carrera. Luego de este análisis se extraen diversas conclusiones en torno a didácticas y metodologías que logran favorecer los aprendizajes matemáticos y, se reconoce que el uso del contexto, las situaciones cotidianas, y todo lo que estas representan contribuyen a la formación de aprendizajes significativos para el estudiante, permitiéndole una visión más amplia respecto a lo que suele ser esta área problémica, ampliando su participación y valorando sus experiencias e ideas en una clase de matemáticas

Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates

The Behavior Response of Amphipods Infected by Hedruris suttonae (Nematoda) and Pseudocorynosoma sp. (Acanthocephala)

The manipulation of intermediate host behavior may increase chances of parasite transmission to the definitive host. In freshwater environments of the Neotropical Region, studies on behavioral manipulations by parasites are rare, and the majority of these only consider a single parasite species and/or 1 life-stage of a particular parasite species. In Andean Patagonian lakes of Argentina, the amphipod Hyalella patagonica is infected by larvae of the fish nematode Hedruris suttonae, and by the bird acanthocephalan Pseudocorynosoma sp. The 3 objectives of the present study were to determine whether H. suttonae and Pseudocorynosoma sp. differ in their effects on behavior of H. patagonica, whether such modification is associated with parasite development, and to assess the associations between behavioral traits. From naturally parasitized amphipods, activity (swimming levels) and phototaxis (light preference) was measured. Only in phototaxis trials, larvae of H. suttonae induced significantly higher levels of photophilia, suggesting that they are manipulative. Scores of activity and phototaxis were positive and significantly related for non-parasitized female amphipods and for amphipods parasitized by larvae of Pseudocorynosoma sp. but were not associated in amphipods parasitized with larvae of H. suttonae (infective and non infective), suggesting that infection separated the relationship between these variables.Fil: Casalins, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Brugni, Norma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Rauque Perez, Carlos Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue; Argentin

Phylogenetic placement of a schistosome from an unusual marine snail host, the false limpet (Siphonaria Lessoni ) and gulls (Larus Dominicanus) from Argentina with a brief review of marine schistosomes from snails

In the blood fluke family Schistosomatidae, marine snails are well known as intermediate hosts. Eight families of marine snails have thus far been reported to host schistosomes across the world, most of which have been implicated in human cercarial dermatitis (HCD) outbreaks. As part of our larger effort to define the species diversity and biology of schistosomes in Argentina, in particular their role in causing HCD, we searched in the marine pulmonate snail (Siphonaria lessoni) for a schistosome species described previously from S. lessoni from southern Argentina. Additionally, gulls (Larus dominicanus) collected from a different project locality (inland) were examined, because they are known to spend time in the intertidal regions. Schistosome sporocysts were found in S. lessoni, and a small worm fragment was retrieved from a gull. Molecular phylogenies for 28S, ITS1-5.8S-ITS2, and cox1 genes revealed that the specimens from the gull and S. lessoni grouped closely together, suggesting they are conspecifics. Also, ITS1-5.8S-ITS2 sequences suggested one of the schistosomes from S. lessoni and a schistosome from a South African penguin were also conspecifics. Further study is needed to verify if these specimens comprise a distinct marine clade within the larger avian schistosome clade that is comprised mostly of species using freshwater snail hosts. Thus far, it appears this group of marine schistosomes may be more likely found in the southern hemisphere. It is unclear if the observed distribution pattern of schistosomes in Siphonaria is a result of sampling bias and/or indicative of a specific bird-snail-schistosome association. It is clear they are sharply differentiated from the basal marine clade of avian schistosomes that includes Austrobilharzia.Fil: Brant, Sara V.. University of New Mexico; Estados UnidosFil: Loker, Eric S.. University of New Mexico; Estados UnidosFil: Casalins, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. University of New Mexico; Estados UnidosFil: Flores, Verónica Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. University of New Mexico; Estados Unido

A new species of Cryptocotyle (Digenea: Heterophyidae) infecting kelp gull and a galaxiid fish in Patagonian freshwater environments: Morphological and molecular analyses

Adults of a species of Cryptocotyle were found infecting the intestine of the kelp gull, Larus dominicanus Lichtenstein, 1823, and metacercariae were found in the fins and muscle of the galaxiid fish, Galaxias platei Steindachner, 1898 (local name ‘‘puyen grande’’), in Nahuel Huapi National Park (Patagonia). Morphometrics and genetic markers of mitochondrial cytochrome oxidase (COI) and ribosomal internal transcribed spacer 1 (ITS1) confirmed that adults and metacercariae were conspecific and represent a new species, Cryptocotyle dominicana n. sp. The only congener known from South America (Cryptocotyle thapari McIntosh, 1953) matures in river otters (Lutra spp. and Pteronura spp.) in Brazil and Bolivia and differs from the new species in the arrangement of the testes, which are located in tandem in the species from otters. Adults of the new species resemble Cryptocotyle lingua (Creplin, 1825) Fischoeder, 1903 from marine environments of the Northern Hemisphere, both species being characterized by having a linguiform body, oblique testes, and vitelline follicles that extend posteriorly to the level of the ventral sucker. Considering the morphological findings that differentiate the new species from other Cryptocotyle, as well as the molecular analysis that shows significant differences from C. lingua, we conclude that these specimens represent a new species, the first of the genus Cryptocotyle to be described from birds in South America.Fil: Casalins, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Arbetman, Marina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Viozzi, Gustavo Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Flores, Verónica Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

Test Patagonia's raptors for rodenticides

Thousands of owls and other predators die each year globally after eating rodents that have been poisoned with anticoagulant rodenticides (ARs) (1–3). In Andean Patagonia, where wilderness areas coexist with human settlements (including tourist destinations), ARs are unregulated and routinely used to prevent human contact with rodents (4, 5). This strategy puts raptors in the region at risk and may be the cause of mass mortality events. However, because testing for ARs is difficult, the extent of ARs’ effects on raptors and other wildlife remains unknown. Given their potential for harm, it is crucial to test for ARs, especially when raptor mass mortality events occur, and to enact policies that regulate their use.Fil: Saggese, Miguel Daniel. Western University Of Health Sciences.; Estados UnidosFil: Plaza, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Casalins, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Ortiz, Gala. Universidad Nacional de La Plata; ArgentinaFil: Ojeda, Valeria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

Nasusbilharzia Flores & Viozzi & Casalins & Loker & Brant 2021, n. gen.

<i>Nasusbilharzia</i> n. gen. <p> <b>Type species:</b> <i>Nasusbilharzia melancorhypha</i> <b>n. sp.</b></p> <p> <b>Etymology:</b> The prefix “ <i>nasus”</i> come from the Latin and refers to the site of infection: the nasal tissue. The suffix “bilharzia” is another name describing a schistosome.</p> <p> <b>Diagnosis:</b> Plathyhelminthes; Trematoda; Digenea; Strigeidida; Schistosomatoidea; Schistosomatidae; Schistosmatinae. Long filamentous worms, somewhat flattened dorso-ventrally. Posterior end of body with blunt termination, not wider than any other part of the body. Oral sucker and ventral sucker present and well developed. Oral sucker terminal. Ventral sucker larger than oral sucker, retractable. Esophagus bifurcating at level of anterior border of ventral sucker. Gynaecophoric canal well-developed starting some distance posterior to ventral sucker. Testes numerous, starting in anterior third of body, posterior to gynaecophoric canal. Cirrus sac present, containing an armed cirrus. Genital pore at anterior end of gynaecophoric canal. Eggs elongated with an asymmetrical median bulge, with slender and curved process in one end.</p>Published as part of <i>Flores, Verónica, Viozzi, Gustavo, Casalins, Laura, Loker, Eric Samuel & Brant, Sara Vanessa, 2021, A new schistosome (Digenea: Schistosomatidae) from the nasal tissue of South America black-necked swans, Cygnus melancoryphus (Anatidae) and the endemic pulmonate snail Chilina gibbosa, pp. 404-418 in Zootaxa 4948 (3)</i> on pages 406-409, DOI: 10.11646/zootaxa.4948.3.5, <a href="http://zenodo.org/record/4629154">http://zenodo.org/record/4629154</a&gt

Nasusbilharzia melancorhypha Flores & Viozzi & Casalins & Loker & Brant 2021, n. sp.

<i>Nasusbilharzia melancorhypha</i> n. sp. <p>(Figs. 4–6)</p> <p> <b>Type host:</b> black necked swan <i>Cygnus melancoryphus</i> (Molina).</p> <p> <b>Type locality:</b> Mari Menuco Lake (38°35′S; 68°32′W) Neuquén Province.</p> <p> <b>Other locality:</b> Pellegrini Lake (38°41′S, 68°01′W) Río Negro Province.</p> <p> <b>Prevalence of infection:</b> 3 of 3 black-necked swans (100%) were infected in Mari Menuco Lake; 2 of 2 swans (100%) were infected in Pellegrini Lake.</p> <p> <b>Site of infection:</b> nasal tissue</p> <p> <b>Etymology:</b> The species name refers to the specific epithet of the definitive host.</p> <p> <b>Type material:</b> Holotype 737, and 15 paratypes 738/1–14 deposited in MACN-Pa. Four paratypes No. 244/1–3 deposited in UNCo-Pa.</p> <p> <b>Deposition of the nucleotide sequences from this paper:</b> MW 000330 - MW 000331; MW 012493 - MW 012494.</p> <p> <b>Description:</b> Based on 20 eggs obtained from both swans of Lake Pellegrini. Eggs (Fig. 4) elongate with an asymmetrical bulge, one end with a slender process either straight or slightly curved, and the opposite end a longer curved process; 215–291 (252.6) long by 34–56 (47.9) wide.</p> <p> Based on 1 complete adult, and 18 anterior pieces of males recovered from nasal tissue <b>(</b> Figs. 5, 6 <b>)</b>. Male long filamentous, somewhat flattened dorso-ventrally, almost uniform width. Posterior end of body with blunt termination, not spatulated nor wider than any other part of the body. Tegument with spines. One complete adult 7,250 long, pieces between 2,414 –10,224 (5,330.3) long, wide at ventral sucker level 48–84 (63.1), at gynaecophoric canal 72–108 (82.5), posterior to gynaecophoric canal 48–84 (57.3). Oral sucker terminal 24–34 (27.7) long by 22–36 (25.8) wide. Esophagus bifurcated anterior to ventral sucker, caecal reunion at level of cirrus sac; reunited intestine continues posteriorly in a sinuous course between testes. Ventral sucker well-developed 26–48 (36.4) long by 24–43 (35.7) wide, ratio ventral to oral sucker length 1: 0.9–1.5 (1.3). Gynaecophoric canal well-developed posterior to ventral sucker, starting at 461–749 (573.7) from anterior end. Gynaecophoric canal is a spiny ventral groove 730–2,160 (1,334.3) long; divided by 17–20 (18) thickened bands. Thickened bands wide 5–7.5 (5.6). Testes spherical or slightly oval, arranged between gynaecophoric canal and posterior end of worm, numerous around 130; 25–45 (31.8) long by 25–45 (35.9) wide. <i>Vesicula seminalis externa</i> contorted starting at 5–24 (14) from ventral sucker, winding to end in cirrus sac, 168–312 (258.5) long by 19–43 (34.1) wide. Cirrus sac present, containing armed cirrus 31–48 (39.3) long. Ejaculatory duct ends at a well-developed cirrus. Armed cirrus located at beginning of gynaecophoric canal, 24–43 (34.6) in diameter. Genital pore at anterior end of gynaecophoric canal.</p> <p> <b>Remarks:</b> The male specimens of <i>Nasusbilharzia melancorhypha</i> <b>n. gen.; n. sp.</b> obtained from the nasal tissues of the black-necked swan have a particular combination of characteristics that make them unique, and do not match with any previous diagnosis of schistosome genera. These worms have a filiform body with spiny tegument, a blunt posterior end, two well developed muscular suckers, a robust gynaecophoric canal with thickened cross bands, armed cirrus, and testes start at the posterior end of the gynaecophoric canal with around 130 testes. Results of the sequence analysis confirm the distinctiveness of these worms and place them at the base of the large avian schistosome clade. They do not group with any of the more commonly found genera from anatids like <i>Allobilharzia</i> Kolářová, Rudolfová, Hampl, & Skírnisson, 2006, <i>Anserobilharzia</i> Brant, Jouet, Ferte, & Loker, 2013, and <i>Trichobilharzia</i> (Figure 2; Table 1). Additionally, relatively few species of <i>Trichobilharzia</i> inhabit the nasal tissue as adults (Table 2, 3).</p> <p>GC = Gynaecophoric canal</p> <p> <i>Nasusbilharzia</i> is similar to <i>Allobilharzia</i> and <i>Anserobilharzia</i> in the development of suckers (Kolářová <i>et al</i>. 2006; Brant <i>et al</i>. 2013), but they differ by having a short gynaecophoric canal in relation to body length, and by having testes that start some distance posterior to the posterior end of the gynaecophoric canal (Table 1). <i>Nasusbilharzia</i> resembles <i>Gigantobilharzia</i> Odhner, 1910 in having an armed cirrus, a gynaecophoric canal with thickened bands and testes starting at the posterior end of gynaecophoric canal but <i>Gigantobilharzia</i> differs by having weakly developed suckers and a broadened body end (Khalil 2002). The new species differs considerably from <i>Dendritobilharzia</i> Skrjabin & Zakharov, 1920 since the latter genus has a shorter gynaecophoric canal and underdeveloped suckers and a cirrus without spines (Table 1). The new species is similar to the nasal <i>Trichobilharzia</i> species (<i>T. rodhaini</i> Fain, 1955, <i>T. nasicola</i> Fain, 1955, <i>T. spinulata</i> Fain, 1956, <i>T. aureliani</i> Fain, 1956, <i>T. duboisi</i> Fain, 1959, <i>T. australis</i> Blair et Islam, 1983, <i>T. arcuata</i> Islam, 1986, <i>T. regenti</i>) in having well-developed suckers, but these <i>Trichobilharzia</i> differ by having a broadened posterior end, and a much shorter gynaecophoric canal without thickened bands (Fain 1955a; 1955b; 1956; 1959; Blair & Islam 1983; Islam 1986, Hórak <i>et al</i>. 1998) (Table 2). In addition, the species described herein differs in having a much longer gynaecophoric canal with at least 17 thickened bands. The infection site is also considered an important taxonomical feature since nasal-inhabiting specimens are not conspecific with specimens in the visceral blood vessels, as it was pointed out for <i>Trichobilharzia</i> species (Blair & Islam 1983).</p> <p>Continued.</p> <p> Ref. = Reference (1) Fain, 1955a; (2) Fain 1956; (3) Fain, 1959; (4) Blair and Islam, 1983; (5) Islam, 1986; (6) Horák <i>et al</i>. 1998;</p> <p>GC = Gynaecophoric canal; (f) = fragments measure, (e) = entire worm measure; OS = oral sucker; VS = ventral sucker; (–) = no data available</p> <p> According to Blair & Islam (1983) almost all <i>Trichobilharzia</i> species produce approximately the same shape of egg. The eggs obtained from nasal tissue of black necked swans are similar in shape to those of <i>Trichobilharzia</i> species from nasal tissues; there is a middle bulge, with one end with a straight to slightly curved process and the opposite end a longer curved one. The egg size of <i>Nasusbilharzia melancorhypha</i> is within the range given for other species that parasite nasal tissue (Table 3). <i>Nasusbilharzia melancorhypha</i> eggs differ from those of the genus <i>Giganthobilharzia</i> which have oval eggs with a spine on one end (Akramova <i>et al</i>. 2010); they differ from <i>Dendritobilharzia</i> eggs which are round to oval, and aspinose (Vande Vusse 1980); they differ from those of <i>Allobilharzia,</i> which have a “duck head” shape at one end, and at the other end, a slender prolongation with a slightly curved process at the top (Kolářová <i>et al</i>. 2006); and they differ from <i>Anseroblharzia</i> eggs which are ovoid and have a small recurved terminal spine (Brant <i>et al</i>. 2013).</p> <p> Ref. = Reference (1) Fain, 1955a; (2) Fain 1956; (3) Fain, 1959; (4) Blair and Islam, 1983; (5) Islam, 1986; (6) Horák <i>et al</i>.</p> <p>1998; (–) = no data available</p>Published as part of <i>Flores, Verónica, Viozzi, Gustavo, Casalins, Laura, Loker, Eric Samuel & Brant, Sara Vanessa, 2021, A new schistosome (Digenea: Schistosomatidae) from the nasal tissue of South America black-necked swans, Cygnus melancoryphus (Anatidae) and the endemic pulmonate snail Chilina gibbosa, pp. 404-418 in Zootaxa 4948 (3)</i> on pages 409-415, DOI: 10.11646/zootaxa.4948.3.5, <a href="http://zenodo.org/record/4629154">http://zenodo.org/record/4629154</a&gt

Hamatospiculum flagellispiculosum (Nematoda: Diplotriaenidae) causing severe disease in a new host from Argentine Patagonia: Campephilus magellanicus (Aves: Picidae)

We describe pathological aspects of an infection caused by parasitic nematodes in skeletal muscles of a Magellanic woodpecker (Campephilus magellanicus), providing the first description of any disease findings in this species. A weakened female with locomotory dysfunction was rescued near Bariloche city (Argentine Patagonia), which soon died. At the necropsy, unexpected masses of tissue were located at three joints (legs and tail). A dissection of these masses exposed numerous nematodes in the musculature surrounding the joints that were identified as Hamatospiculum flagellispiculosum (Nematoda: Diplotriaenidae), a species that was not previously found in Piciformes (woodpeckers, toucans, and allies) of the Neotropical Region. In this report, we complement the original parasite description from 1952 with SEM images, and extend the species range about 2000 km southwards. Histopathological analysis (tissues sectioned 4–6 microns, stained with hematoxylin and eosin) of the affected tissues revealed parasitic myositis with muscle fibrosis. Severe muscle degeneration and necrosis, fibrous tissue replacing muscle tissue, chronic inflammation with widespread diffuse mononuclear infiltration, and parasitic content (adult roundworms, eggs, and eggs with first-stage larvae) were present in all samples. The multifocal nature of these lesions was consistent with the locomotory dysfunction exhibited by the bird. Both the immune response (mononuclear infiltration without eosinophils, which normally fight helminth colonization) and the clinical severity of this case (a lethal, multifocal macroparasite infection) are noteworthy. The expected immune response may have been suppressed through immunomodulation by the parasite, as observed for filarial parasites. Based on their demography and life history traits (i.e., long-lived picids that produce a single nestling every 1–2 years, and live in sparse populations), Magellanic Woodpeckers do not seem to be obvious hosts of an obligately killing parasite, and other (more regular) hosts should be expected to occur in the same region. Keywords: Dicheilonematinae, Hamatospiculum flagellispiculosum, Histopathology, Locomotory dysfunction, Magellanic woodpecker, SE