Oxyura Jamaicensis Research Articles

Body mass changes of dabbling and diving ducks wintering in California

AbstractBird body mass is often used as an index of body condition and fluctuates throughout the year in response to environmental conditions and avian life‐history events. We examined the body mass of 59,572 ducks representing 13 species (7 dabbling duck species and 6 diving duck species) harvested within the 3 regions of the Central Valley in California, USA (Sacramento Valley, Suisun Marsh, San Joaquin Valley). Data collection occurred in winter during 5 hunting seasons (2014–2015, 2015–2016, 2017–2018, 2018–2019, 2019–2020). For all species, age, and sex classes, the body mass of dabbling ducks varied temporally and was lowest at the end of the hunting season in late January, declining from the beginning of the hunting season in mid‐October (northern pintail [Anas acuta]: −11.4% to −20.4%; northern shoveler [Spatula clypeata]: −3.5% to −17.3%; cinnamon teal [Anas cyanoptera]: −5.0% to −17.1%; American wigeon [Mareca americana]: −6.9% to −12.2%; American green‐winged teal [Anas carolinensis]: −5.9% to −11.9%; mallard [Anas platyrhynchos]: −1.8% to −9.6%; gadwall [Mareca strepera]: −2.2% to −8.4%). As expected, adults (after hatch‐year) were heavier than immature (hatch‐year) birds (within males: 0.6–8.6%; within females: 0.1–6.6%) and males were heavier than females (within adults: 3.1–38.6%; within immatures: 5.4–33.5%) at the end of the hunting season in all species. Within dabbling duck species, body masses did not differ among regions at the beginning of the hunting season but were heavier in the Sacramento Valley (0.5–14.4%) than other areas by the end of the hunting season. In contrast, body masses of diving ducks did not vary substantially during the hunting season or among regions. Diving ducks demonstrated inconsistent changes in mass from the beginning to the end of the season (lesser scaup [Aythya affinis]: 3.4% to 12.3%; canvasback [Aythya valisineria]: 5.1% to 6.1%; bufflehead [Bucephala albeola]: −3.2% to 1.6%; ring‐necked duck [Aythya collaris]: −4.9% to 2.6%; common goldeneye [Bucephala clangula]: −3.2% to −2.4%; ruddy duck [Oxyura jamaicensis]: −16.5% to 5.5%). The substantial temporal and spatial differences in dabbling duck body masses suggest that habitat quality (as measured by caloric value of the available food) or quantity may decline during winter and varies regionally within California's Central Valley.

Diving at High Altitude: O2 Transport and Utilization in the Ruddy Duck and Torrent Duck in the Andes

Diving at High Altitude: O2 Transport and Utilization in the Ruddy Duck and Torrent Duck in the Andes

Oxyura jamaicensis (ruddy duck)

This datasheet on Oxyura jamaicensis covers Identity, Overview, Distribution, Dispersal, Biology & Ecology, Environmental Requirements, Impacts, Uses, Prevention/Control, Further Information.

A PRÉCIS AND CHECKLIST OF HELMINTH PARASITES FOR 14 SPECIES OF WATERFOWL FROM THE CHIHUAHUA DESERT IN THE UNITED STATES AND MEXICO.

A précis of helminth parasite infections and a host-parasite checklist are presented for the following 14 species of waterfowl from the Chihuahua Desert in the United States and Mexico: Chen rossii, Chen caerulescens, Anas platyrhynchos, Anas diazi, Anas acuta, Anas strepera, Anas americana, Anas clypeata, Anas cyanoptera, Anas crecca, Bucephala albeola, Oxyura jamaicensis, Fulica americana, and Podiceps nigricollis. There was a total of 127 species of helminths recovered from the 14 species of waterfowl. Total abundance, which included data available for 12 species of waterfowl, was 134,202 (mean = 11,184, median = 1,376, and 95% confidence limit [CL] = 14,485). Mean species richness ranged from 1.5 in Ross's goose, C. rossii, to 4.3 in the bufflehead, B. albeola. Host mean abundance ranged from 7.5 in the Mexican duck, A. diazi, and green-winged teal, A. crecca, to a high of 811 for the ruddy duck, O. jamaicensis. Ninety-one percent of the helminth species were generalists. Most specialists were associated with the American coot, F. americana (7), and the eared grebe, P. nigricollis (5). Percent helminth species contribution was cestodes 45%, nematodes 25%, trematodes 22%, and acanthocephalans 8%. The most commonly occurring helminth species among the 14 host species were the trematode Notocotylus attenuatus (12), the cestode Cloacotaenia megalops (10), the acanthocephalan Corynosoma constrictum (9), and the nematode Capillaria anatis (6). Low ingestion of invertebrates may have contributed to the lower number of helminth species and abundance in wintering and spring dabbling ducks (Anatini). Wild dabbling ducks ranging in age from 6 mo to 8 yr and 8 mo were infected with helminth parasites. Helminth parasite data from resident and nesting hosts and pre-fledged young birds indicated as many as 43 helminth life cycles may be occurring in the Chihuahua Desert. Host-parasite species checklists are included.

Gastrointestinal helminths of waterfowl (Anatidae: Anatinae) in the Lerma marshes of central Mexico: Some pathological aspects.

Gastrointestinal helminths of migratory waterfowl can cause several lesions that may affect the health and even the survival of their hosts. As part of an ongoing project that aims to inventory the helminth species that infect this group of birds, as well as the histopathologic lesion they cause, a total of 200 digestive tracts of nine species of anatid birds (Spatula discors, S. cyanoptera, S. clypeata, Mareca strepera, M. americana, Anas crecca, A. acuta, A. platyrhynchos diazi, and Oxyura jamaicensis) were collected in the Atarasquillo marsh of Lerma, in the State of Mexico. The present work had a twofold goal: to determine the taxonomic identity of the helminth species present in waterfowl as well as their infection levels and to describe the lesions caused by gastrointestinal parasites in migratory and resident anatids in Atarasquillo marsh, State of Mexico. The specimens were examined using routine helminthological and histopathological techniques. A total of 23 helminths were identified: six trematodes (Zygocotyle lunata, Notocotylus triserialis, Notocotylus seineti, Psilochasmus oxyurus, Australapatemon burti and Cotylurus magniacetabulus), four cestodes (Cloacotaenia megalops, Fimbriaria fasciolaris, Gatrotaenia cygni and Diorchis sp.), eleven nematodes (Echinuria uncinata, Tetrameres sp., Tetrameres fissispina, Hystrichis sp., Streptocara sp., Amidostomum sp., Epomidiostomum uncinatum, Capillaria sp., Capillaria contorta, Ascaridia sp. and Heterakis sp.) and two acanthocephalans (Pseudocorynosoma constrictum and Filicollis sp.). At the proventriculus level, Echinuria uncinata caused the most severe lesions; in the gizzard, Amidostomum sp. and E. uncinatum produced hemorrhages and necrosis. Finally, the main lesions found in the intestine (necrosis, heterophilic granulomas and the formation of lumps on the serosa) were caused by the implantation of the acanthocephalans’ proboscis. Eleven species of gastrointestinal helminths found are new records for the Lerma marshes, as well as the first record in Mexico of the nematode Capillaria contorta and the acanthocephalan Filicollis sp.

Waterbird Migration through a Saline Wetland in the Western Nevada Desert, USA

A great variety of waterbirds migrate across western Nevada, where places to rest or refuel are nearly non-existent. One exception is a little-known industrial pond complex at the Albemarle U.S., Inc. facility in Silver Peak. In this paper we analyzed 3 years (2014-2016) of near-daily counts to document the timing, abundance, and stopover biology of 73 species traversing one of the driest regions in North America. Average annual bird-use-days exceeded 350,000, of which 93% were contributed by species with affinities to highly saline habitats. Individuals of most species (total estimated 110,000-183,000) passed through within a day or so, although some Ruddy Ducks (Oxyura jamaicensis), Eared Grebes (Podiceps nigricollis) and American Avocets (Recurvirostra americana) made prolonged stays. We treat the most abundant species in detail and show that data from sites that can be monitored daily can complement studies from sites where daily censuses are not feasible. The Silver Peak ponds attract sufficient shorebirds to warrant consideration as a Site of Regional Importance in the Western Hemisphere Shorebird Reserve Network.

A morphometric analysis of the lungs of high-altitude ducks and geese.

We examined the morphology of the lungs of five species of high-altitude resident ducks from Lake Titicaca in the Peruvian Andes (yellow-billed pintail [Anas georgica], cinnamon teal [Anas cyanoptera orinomus], puna teal [Anas puna], speckled teal [Anas flavirostris oxyptera], and ruddy duck [Oxyura jamaicensis ferruginea]) and compared them with those of the high-altitude migratory bar-headed goose (Anser indicus) and the low-altitude migratory barnacle goose (Branta leucopsis). We then determined the relationship between mass-specific lung volume, the volume densities of the component parts of the lung, and previously reported hypoxia-induced increases in pulmonary O2 extraction. We found that the mass-specific lung volumes and the mass-specific volume of the exchange tissue were larger in the lungs of high-altitude resident birds. The bar-headed goose had a mass-specific lung volume that fell between those of the low-altitude species and the high-altitude residents, but a mass-specific volume of exchange tissue that was not significantly different than that of the high-altitude residents. The data suggest that the mass-specific volume of the lung may increase with evolutionary time spent at altitude. We found an inverse relationship between the percentage increase in pulmonary O2 extraction and the percentage increase in ventilation across species that was independent of the volume density of the exchange tissue, at least for the resident Andean birds.

FOURTH REPORT OF THE COMMITTEE FOR ECUADORIAN RECORDS IN ORNITHOLOGY (CERO) AND A REVISION OF UNDOCUMENTED AND ERRONEOUS RECORDS IN LITERATURE

We present new distributional records of birds in Ecuador submitted to the Committee for Ecuadorian Records in Ornithology (CERO) from September 2015 through July 2017. This report includes four species new to Ecuador (Plegadis ridgwayi, Cathartes burrovianus, Malacoptila mystacalis, Vireo gilvus), two species new to Galapagos (Calidris pugnax, Larosterna inca), five species with first documented country records (Fregata minor, Syrigma sibilatrix, Calidris pugnax, Larus belcheri, Sternula antillarum), remarkable range extensions for eight species (Anas bahamensis, Fregata sp., Jabiru mycteria, Phimosus infuscatus, Caracara cheriway, Larus dominicanus, Chloroceryle aenea, Sturnella militaris), new records of eight rare species (Anhima cornuta, Mustelirallus albicollis, Larus argentatus, Larosterna inca, Myrmoborus lugubris, Machetornis rixosa, Progne elegans, Conirostrum bicolor) and new records of Nothoprocta curvirostris and Tyrannus tyrannus. We present the first Ecuadorian records of three subspecies (Tolmomyias sulphurescens insignis, Myiarchus swainsoni phaenotus, Oxyura jamaicensis andina, although the taxonomic validity of the latter is debated). Further we discuss the subspecific identity of Petrochelidon pyrrhonota in Ecuador. Finally, we invalidate previous records of 43 species for mainland Ecuador and 6 species for Galapagos, as published in different sources, and reject a remotesensing record of Cypseloides niger. CERO revises and updates the country bird list, which currently stands at 1690 species (1632 confirmed and documented; 58 undocumented).

Cardiovascular responses to progressive hypoxia in ducks native to high altitude in the Andes.

The cardiovascular system is critical for delivering O2 to tissues. Here we examine the cardiovascular responses to progressive hypoxia in four high-altitude Andean duck species compared to four related low-altitude populations in North America, tested at their native altitude. Ducks were exposed to stepwise decreases in inspired partial pressure of O2 while we monitored heart rate, O2 consumption rate, blood O2 saturation, haematocrit (Hct), and blood haemoglobin concentration [Hb]. We calculated O2 pulse (the product of stroke volume and the arterial-venous O2 content difference), blood O2 concentration, and heart rate variability. Regardless of altitude, all eight populations maintained O2 consumption rate with minimal change in heart rate or O2 pulse, indicating that O2 consumption was maintained by either a constant arterial-venous O2 content difference (an increase in the relative O2 extracted from arterial blood) or by a combination of changes in stroke volume and the arterial-venous O2 content difference. Three high-altitude taxa (yellow-billed pintails, cinnamon teal, and speckled teal) had higher Hct and [Hb], increasing the O2 content of arterial blood, and potentially providing a greater reserve for enhancing O2 delivery during hypoxia. Hct and [Hb] between low- and high-altitude populations of ruddy duck were similar, representing a potential adaptation to diving life. Heart rate variability was generally lower in high-altitude ducks, concurrent with similar or lower heart rates than low-altitude ducks, suggesting a reduction in vagal and sympathetic tone. These unique features of the Andean ducks differ from previous observations in both Andean geese and bar-headed geese, neither of which exhibit significant elevations in Hct or [Hb] compared to their low-altitude relatives, revealing yet another avian strategy for coping with high altitude.

Northwestern Limit of the Breeding Range of the Ruddy Duck

Northwestern Limit of the Breeding Range of the Ruddy Duck

Time-activity budgets of stiff-tailed ducks in Puerto Rico

Habitat loss and degradation have contributed to declining populations of stiff-tailed ducks including the migratory northern ruddy duck (Oxyura jamaicensis rubida), and non-migratory masked duck (Nomonyx dominicus) and West Indian ruddy duck (Oxyura j. jamaicensis). Studies collecting time-activity budgets on waterfowl can provide important insight into habitat use, behavior, and niche partitioning. Even though the northern ruddy duck and West Indian ruddy duck are recognized as the same species, we treated them separately to appraise possible ecological differences. We recorded 24-h time-activity budgets for masked ducks (n = 142), northern ruddy ducks (n = 1,401), and West Indian ruddy ducks (n = 3,765) on the Laguna Cartagena National Wildlife Refuge in Lajas, Puerto Rico from January through April 2015 and 2016. Behaviors varied among taxa, between sexes, and between diurnal and nocturnal sampling periods. Resting and sleeping were common behaviors observed during the day and night, but all 3 taxa fed more at night with masked duck feeding more than the West Indian ruddy duck and northern ruddy duck. Northern ruddy duck and West Indian ruddy duck time-activity budgets varied with 7 of 8 behavioral categories during the day and 5 of 8 behavioral categories at night differing. Ecological differences such as body size and migration of northern ruddy ducks may account for the differences in behavior when compared to non-migratory West Indian ruddy ducks.

Neutral and functionally important genes shed light on phylogeography and the history of high-altitude colonization in a widespread New World duck.

Phylogeographic studies often infer historical demographic processes underlying species distributions based on patterns of neutral genetic variation, but spatial variation in functionally important genes can provide additional insights about biogeographic history allowing for inferences about the potential role of adaptation in geographic range evolution. Integrating data from neutral markers and genes involved in oxygen (O2)‐transport physiology, we test historical hypotheses about colonization and gene flow across low‐ and high‐altitude regions in the Ruddy Duck (Oxyura jamaicensis), a widely distributed species in the New World. Using multilocus analyses that for the first time include populations from the Colombian Andes, we also examined the hypothesis that Ruddy Duck populations from northern South America are of hybrid origin. We found that neutral and functional genes appear to have moved into the Colombian Andes from both North America and southern South America, and that high‐altitude Colombian populations do not exhibit evidence of adaptation to hypoxia in hemoglobin genes. Therefore, the biogeographic history of Ruddy Ducks is likely more complex than previously inferred. Our new data raise questions about the hypothesis that adaptation via natural selection to high‐altitude conditions through amino acid replacements in the hemoglobin protein allowed Ruddy Ducks to disperse south along the high Andes into southern South America. The existence of shared genetic variation with populations from both North America and southern South America as well as private alleles suggests that the Colombian population of Ruddy Ducks may be of old hybrid origin. This study illustrates the breadth of inferences one can make by combining data from nuclear and functionally important loci in phylogeography, and underscores the importance of complete range‐wide sampling to study species history in complex landscapes.

Diurnal and Nocturnal Dive Durations and Inter-Dive Intervals of Stiff-Tailed Ducks in Puerto Rico

Research comparing dive durations and inter-dive intervals of stiff-tailed diving ducks, which is important for understanding differences in species ecology, is lacking for the non-migratory Masked Duck (Nomonyx dominicus) and West Indian Ruddy Duck (Oxyura jamaicensis jamaicensis), and the migratory Northern Ruddy Duck (Oxyura jamaicensis jamaicensis). Although the Northern Ruddy Duck and West Indian Ruddy Duck are considered the same species, we treated them separately to evaluate possible ecological differences. All three were observed at the same time in the same place in Laguna Cartagena National Wildlife Refuge, Puerto Rico. Dive durations and inter-dive intervals were recorded for Masked Duck (n = 60), Northern Ruddy Duck (n = 70), and West Indian Ruddy Duck (n = 445) from 1 January through 30 April 2015 and 2016. The Northern Ruddy Duck had a longer mean (± SE) dive duration (22.9 ± 0.75 sec) than the West Indian Ruddy Duck (18.8 ± 0.02 sec). Northern Ruddy Ducks likely had longer dive times because of their larger body size and migratory behavior.

Biología reproductiva de anátidos (Familia Anatidae) en la Laguna de Zumpango, Estado de México

La Laguna de Zumpango se ha convertido en un humedal urbano fuertemente influenciado por actividades humanas, lo que ha puesto en riesgo su biodiversidad. Esta laguna es uno de los últimos relictos de la Cuenca de México que aún alberga una gran diversidad de aves acuáticas y varias especies la utilizan como zona de anidación. En este estudio describimos algunos aspectos de la biología reproductiva de aves de la familia Anatidae en la Laguna de Zumpango. Registramos cinco especies que anidan en esta zona: el pijije canelo (Dendrocygna bicolor), el pato mexicano (Anas platyrhynchos diazi), la cerceta canela (Anas cyanoptera), el pato tepalcate (Oxyura jamaicensis), y una especie que había sido considerada como visitante de invierno: el pato friso (Anas strepera). La temporada reproductiva de 2015 inició en febrero y culminó en septiembre. Describimos el sustrato utilizado para la construcción del nido, el tamaño de nidada para tres especies y el éxito de eclosión para una. Determinamos entre las principales causas de fracaso reproductivo el abandono del nido, la reducción de la nidada y la infertilidad de los huevos. Reportamos por primera vez cuidado parental cooperativo para O. jamaicensis. La Laguna de Zumpango es un hábitat primordial para la reproducción de aves acuáticas como los patos, que ven afectado su éxito de anidación por la continua transformación y perturbación de su hábitat. Sugerimos medidas que ayuden a mitigar la perturbación de las aves y sus nidos durante la temporada reproductiva y para mantener las zonas de anidación.

Cambios temporales de la avifauna acuática en el sitio Ramsar “Presa de Valsequillo”, Puebla, México

La Convención de Ramsar busca promover la conservación y el uso sostenible de los humedales de importancia internacional y sus recursos biológicos. En 2012, la Presa de Valsequillo (Puebla, México) fue aceptada como sitio Ramsar, pero se desconocen aún aspectos de la ecología de su avifauna. Con este estudio se incrementó el conocimiento sobre la importancia ornitológica de este sitio Ramsar en el que evaluamos la variación temporal de la estructura de la comunidad de aves acuáticas. Primero, desde febrero de 2014 a enero de 2015, estimamos mensualmente la riqueza y abundancia de aves acuáticas de la Presa desde una embarcación con motor fuera borda, y se usó esta información para analizar los cambios en la riqueza y la diversidad. Después, mediante técnicas de análisis multivariante, obtuvimos grupos de meses con base en su similitud y comprobamos su significación estadística. Finalmente, identificamos las especies responsables de tales cambios. En total, observamos 30 especies de aves acuáticas, pero la riqueza mensual (estandarizada a 768 individuos) varió entre 12 y 20. En ‘primavera-verano’, la comunidad de aves acuáticas fue más sencilla (i.e., con menores valores de abundancia, riqueza y diversidad) que en ‘otoño-invierno’. Los principales cambios en la estructura de la comunidad se debieron a variaciones en la abundancia de unas pocas especies: la gallareta americana (Fulica americana), el pato cucharón (Anas clypeata) y el pato tepalcate (Oxyura jamaicensis). Sin excluir otras posibilidades para estos cambios, nuestro estudio sugiere que los patos (Anatidae) utilizan principalmente la Presa de Valsequillo como un sitio de invernada, mientras que las garzas (Ardeidae) la utilizan como una escala en sus movimientos migratorios otoñales. Nuestros datos pueden aplicarse en programas de ecoturismo (observación de aves), buscando las fechas que permitan maximizar el número de especies observadas, su diversidad o su abundancia.

Evidence of phenotypic plasticity of penis morphology and delayed reproductive maturation in response to male competition in waterfowl

ABSTRACT Ducks are an excellent group to study avian genital evolution. Penis morphology of ducks is diverse, and penis length and elaboration are positively correlated with levels of male competition resulting from forced extra-pair copulations, and with female genital elaboration resulting from sexual conflict. Here we examined whether penis morphology is affected by social environment. We found experimental evidence that in a male-biased social environment, consisting of several males and fewer females, the penis in Lesser Scaup (Aythya affinis) grew longer in 2 separate years, than in males housed in pairs, as predicted if male–male competition influences penis morphology. In Ruddy Ducks (Oxyura jamaicensis), males instead showed evidence of reproductive delays that were explained both by a male's size and his social environment: most males in social groups exhibited shorter penises, variable onset and duration of genital maturation, and faster penis growth rate. These 2 species have different levels ...

Wintering Waterfowl Avoidance and Tolerance of Recreational Trail Use

Abstract. An experimental approach was used to investigate wintering waterfowl responses to introduced trail use at foraging sites with and without recreational trails in California, USA. Waterfowl were exposed to trail use in the form of two researchers walking levees adjacent to ponded habitat, and the number of waterfowl by species were compared before and after experimental walks in 40-m bands starting at the levee and extending 200 m into the ponds. The researchers recorded distances to the nearest individuals, responses of focal animals, and numbers of recreational trail users. The most numerous species were Ruddy Duck (Oxyura jamaicensis), Northern Shoveler (Anas clypeata), and scaup spp. (Aythya affinis and A. marila). Recreational trail use rates at trail sites averaged 1 to 82 people/hr. The greatest difference in numbers of birds before vs. after experimental walks occurred in the two 40-m bands closest to the levee at non-trail sites (0–40 m [t = 4.558, P = 0.0001], 40–80 m [t = 3.775, P = 0.0...

THE PATHOGENESIS OF CLADE 2.3.4.4 H5 HIGHLY PATHOGENIC AVIAN INFLUENZA VIRUSES IN RUDDY DUCK (OXYURA JAMAICENSIS) AND LESSER SCAUP (AYTHYA AFFINIS).

Waterfowl are the natural hosts of avian influenza virus (AIV) and disseminate the virus worldwide through migration. Historically, surveillance and research efforts for AIV in waterfowl have focused on dabbling ducks. The role of diving ducks in AIV ecology has not been well characterized. In this study, we examined the relative susceptibility and pathogenicity of clade 2.3.4.4 H5 highly pathogenic AIV (HPAIV) in two species of diving ducks. Juvenile and adult Ruddy Duck (Oxyura jamaicensis) and juvenile Lesser Scaup (Aythya affinis) were intranasally inoculated with A/Northern Pintail/WA/40964/2014 H5N2 HPAIV. Additional groups of juvenile Lesser Scaups were inoculated with A/Gyrfalcon/WA/41088/2014 H5N8 HPAIV. The approximate 50% bird infectious doses (BID50) of the H5N2 isolate for adult Ruddy Ducks was <102 50% egg infectious doses (EID50) and for the juvenile Lesser Scaups it was <104 EID50. There were insufficient juvenile Ruddy Ducks to calculate the BID50. The BID50 for the juvenile Lesser Scaups inoculated with the H5N8 isolate was 103 EID50. Clinical disease was not observed in any group; however, mortality occurred in the juvenile Ruddy Ducks inoculated with the H5N2 virus (three of five ducks), and staining for AIV antigen was observed in numerous tissues from these ducks. One adult Ruddy Duck also died and although it was infected with AIV (the duck was positive for virus shedding and AIV antigen was detected in tissues), it was also infected with coccidiosis. The proportion of ducks shedding virus was related to the dose administered, but the titers were similar among dose groups. The group with the fewest ducks shedding virus was the adult Ruddy Ducks. There was a trend for the Lesser Scaups to shed higher titers of virus than the Ruddy Ducks. No virus shedding was detected after 7 d postinoculation in any group. Similar to dabbling ducks, Lesser Scaups and Ruddy Ducks are susceptible to infection with this H5 HPAIV lineage, although they excrete lower titers of virus.

A morphological and molecular study of Pseudocorynosoma Aznar, Pérez Ponce de León and Raga 2006 (Acanthocephala: Polymorphidae) from Mexico with the description of a new species and the presence of cox 1 pseudogenes

Pseudocorynosoma tepehuanesi n. sp., is described from the intestine of the ruddy duck Oxyura jamaicensis Gmelin, 1789 from single locality from northern Mexico. The new species is mainly distinguished morphologically from the other five described species of Pseudocorynosoma from the Americas (P. constrictum, type species, P. peposacae, P. anatarium, P. enrietti and P. iheringi) associated with waterfowl species by possessing a proboscis with 15 longitudinal rows with 7–8 hooks each, a trunk expanded anteriorly and by having smaller lemniscus. Partial sequences of the mitochondrial gene cytochrome c oxidase subunit I (cox 1) and the large subunit (LSU) of ribosomal DNA including the domains D2+D3 were used independently to corroborate the morphological distinction between the new species and other two congeneric species (P. constrictum and P. anatarium) from North America. The genetic divergence estimated among the new species and the other two species ranged from 15 to 18% for cox 1 and from 3.2 to 4% for LSU. The cox 1 alignment shows 24 sequences from P. anatarium with abnormalities, which were defined as pseudogenes due the presence of insertions, deletions and premature stop codons. Maximum likelihood and Bayesian inference analyses with each data set showed that the acanthocephalans from ruddy duck represent an independent clade with strong bootstrap support and posterior probabilities. The phylogenetic tree inferred with cox 1 gene placed all the pseudogenes from P. anatarium in single clade suggesting that those genes arose after speciation process within genus Pseudocorynosoma. The morphological evidence, plus the monophyly in both phylogenetic analyses indicate that the acanthocephalans collected from intestine of the ruddy duck from northern Mexico represent a new species.

First molecular identification of Australapatemon burti (Miller, 1923) (Trematoda: Digenea: Strigeidae) from an intermediate host Radix labiata (Rossmaessler) (Gastropoda: Lymnaeidae) in Europe.

The strigeid digenean species Australapatemon burti (Miller, 1923) (Trematoda: Digenea: Strigeidae) was originally described from North America, but recorded in the Neotropical region (Drago et al. 2007; Hernández-Mena et al. 2014; Blasco-Costa et al. 2016) and in Central Europe (Faltýnková et al. 2007). In Europe, this species is rare, and there is not much information about its range (Faltýnková et al. 2007; Soldánová et al. 2012). Australapatemon burti has a complex life cycle with three larval stages, two of which (sporocyst and cercaria) use several species of freshwater snails, and the third stage (metacercaria) use non-specific host hirudineans (Dubois 1968; Davies & Ostrowski de Núñez 2012; Blasco-Costa et al. 2016). Adult flukes are parasitic in the intenstines of various waterfowl species, such as ducks and swans (Drago et al. 2007; Hernández-Mena et al. 2014). Currently, the molecular data on this parasite species includes only nucleotide sequences of four adult specimens from Mexico (Hernández-Mena et al. 2014). Their hosts were Mexican duck, Anas diazi Ridgway, American Wigeon, Anas americana Gmelin, Cinnamon Teal, Anas cyanoptera Vieillot, and Ruddy Duck, Oxyura jamaicensis (Gmelin) (Anserformes: Anatidae).