Helminth and ectoparasitic faunas of the Harris's hawk, Parabuteo unicinctus (Accipitriformes: Accipitridae), in Chile: new data on host-parasite associations for Neotropical raptors / Helmintos e ectoparasitas do gavião-asa-de-telha (Accipitriformes: Parabuteo unicinctus) no Chile: novas associações parasita-hospedeiro para os rapinantes neotropicais

Abstract Birds of prey harbor a wide spectrum of various parasites, mostly with a heteroxenous life cycle. However, most reports on their parasites come from Europe. Although the Harris's hawk (Parabuteo unicinctus) is a widespread species in America, parasitological surveys on this hawk are mostly focused on coprological findings and ectoparasites, with poor attention paid to helminths. The aim of this study was to gather new and additional data on host-parasite associations for the Harris's hawk. Twenty-nine birds from central and southern Chile were necropsied. Further, nine birds from a rehabilitation center and 22 museum specimens were inspected for ectoparasites. Sixty-eight percent of birds hosted at least one parasite species. Four lice species, one mite species and eight helminth species (five nematodes, two platyhelminthes and one acanthocephalan) were recorded. Parasitic lice Colpocephalum nanum and Nosopon chanabense, and a nematode Cyathostoma (Hovorkonema) americana were recorded for the first time in raptors from the Neotropics. A feather mite, Pseudalloptinus sp., nematodes, Physaloptera alata and Microtetrameres sp., and a trematode Neodiplostomim travassosi, were recorded for the first time in Chile. The presence of diverse heteroxenous helminths reported here in the Harris's hawk could be explained by the generalist diet of this raptor.

Resumo As aves de rapina representam uma fonte importante de parasitas heteroxenos. Porém, a maioria dos relatos são da Europa. O gavião-asa-de-telha (Parabuteo unicinctus) é uma espécie amplamente distribuída no continente Americano, porém estudos parasitológicos nessas aves têm documentado achados coprológicos e ectoparasitas, com poucos relatos sobre endoparasitas como helmintos. Por essa razão, o objetivo deste estudo foi descrever novas associações parasita-hospedeiro para o gavião-asa-de-telha e rapinantes neotropicais. Vinte nove aves provenientes do centro e sul do Chile foram submetidas à necropsia. Por outro lado, nove aves de um centro de reabilitação e 22 espécimes de museu foram inspecionados em busca de ectoparasitas. Do total de aves, 68,3% foram identificadas como portadoras de pelo menos uma espécie de parasita. Quatro espécies de piolhos, um ácaro e oito helmintos (cinco nematoides, dois platelmintos e um acantocéfalo) foram registrados. Os piolhos Colpocephalum nanum, Nosopon chanabense e o nematóide Cyathostoma (Hovorkonema) americana são reportados pela primeira vez em rapinantes neotropicais. Colpocephalum nanum, N. chanabense, Pseudalloptinus sp., Physaloptera alata, Microtetrameres sp., C. (H.) americana e Neodiplostomim travassosi, são reportados pela primeira vez no Chile. A diversidade de helmintos heteróxenos, identificados neste trabalho, poderia ser explicada devido à dieta geralista do gavião-asa-de-telha.

MOLECULAR IDENTIFICATION OF JUVENILE NEOECHINORHYNCHUS SPP. (PHYLUM: ACANTHOCEPHALA) INFECTING OSTRACOD AND SNAIL HOSTS PROVIDES INSIGHT INTO ACANTHOCEPHALAN HOST USE.

The role of invertebrates in some acanthocephalan life cycles is unclear because juvenile acanthocephalans are difficult to identify to species using morphology. Most reports suggest acanthocephalans from turtle definitive hosts use ostracods as intermediate hosts and snails as paratenic hosts. However, laboratory studies of the life cycle suggest that ostracods and snails are both required hosts in the life cycle. To elucidate the role of ostracods and snails in acanthocephalan life cycles better, we collected 558 freshwater snails of 2 species, including Planorbella cf. Planorbella trivolvis and Physa acuta, from 23 wetlands in Oklahoma, U.S.A., and examined them for acanthocephalan infections. Additionally, we examined 37,208 ostracods of 4 species, Physocypria sp. (morphotype 1), Cypridopsis sp., Stenocypris sp., and Physocypria sp. (morphotype 2) for juvenile acanthocephalans from 2 wetlands in Oklahoma. Juvenile acanthocephalans were morphologically characterized, and the complete internal transcribed spacer (ITS) region of nuclear rDNA was sequenced from acanthocephalans infecting 11 ostracod and 13 snail hosts. We also sampled 10 red-eared slider turtles, Trachemys scripta elegans, and 1 common map turtle, Graptemys geographica, collected from Oklahoma, Arkansas, and Texas and recovered 1,854 adult acanthocephalans of 4 species. The ITS of 17 adult acanthocephalans of 4 species from turtle hosts were sequenced and compared to juvenile acanthocephalan sequences from ostracod and snail hosts from this study and GenBank to determine conspecificity. Of the 23 locations sampled for snails, 7 (30%) were positive for juvenile acanthocephalans in the genus Neoechinorhynchus. The overall prevalence and mean intensity of acanthocephalans in Planorbella cf. P. trivolvis and P. acuta were 20% and 2 (1-6) and 2% and 1 (1), respectively. In contrast, only 1 of 4 species of ostracods, Physocypria sp. (morphotype 1), was infected with larval/juvenile Neoechinorhynchus spp. with an overall prevalence of 0.1% and a mean intensity of 1 (1-2). Although 4 species of acanthocephalans infected turtle definitive hosts, including Neoechinorhynchus chrysemydis, Neoechinorhynchus emydis, Neoechinorhynchus emyditoides, and Neoechinorhynchus pseudemydis, all the ITS sequences from cystacanths infecting snail hosts were conspecific with N. emydis. In contrast, the ITS sequences from larval/juvenile acanthocephalans from ostracods were conspecific with 2 species of acanthocephalans from turtles (N. emydis and N. pseudemydis) and 1 species of acanthocephalan from fish (Neoechinorhynchus cylindratus). These results indicate that N. emydis infects freshwater snails, whereas other species of Neoechinorhynchus appear not to infect snail hosts. We document new ostracod and snail hosts for Neoechinorhynchus species, including the first report of an ostracod host for N. pseudemydis, and we provide novel molecular barcodes that can be used to determine larva, juvenile, and adult conspecificity of Neoechinorhynchus species.

MORPHOLOGY OF ADULTS AND IMMATURES OF THE ACANTHOCEPHALAN, POMPHORHYNCHUS FUHAIENSIS YUE, 1998 (ACANTHOCEPHALA: POMPHORHYNCHIDAE) FROM CYPRINID FISH IN NORTHWEST CHINA.

Adult specimens of Pomphorhynchus fuhaiensis were identified from common carp (Cyprinus carpio L.) in Ulungur Lake of northwest China, and acanthors, acanthellae, cystacanths dissected from Gammarus lacustris in a small tributary of Ulungur River for the first time. The acanthocephalans were also found in crucian carp (Carassius carassius L.), tench (Tinca tinca L.), oriental bream (Abramis brama orientalis Berg), and ide (Leuciscus idus L.) in the lake. This species is distinguished from other species in Pomphorhynchus by its large, spherical bulb and very long neck as well as by a cylindrical proboscis armed with 15-17 longitudinal rows of 9-12 hooks each. The anterior proboscis hooks are almost uniform in size and shape, the sixth hook in a short row and the seventh hook in long row decrease abruptly in size posteriorly with the last end hook being a little larger than the prebasal hook, and in a ring; posterior proboscis hooks much more widely spaced. Furthermore, the lemnisci are claviform. The mean neck:trunk ratio is about 0.5, which is larger than most other species in Pomphorhynchus. Females are larger than males. In males, the testes are in one-third to one-half of the trunk, equal, ovoid-spheroid, usually contiguous, and small relative to the body size, and there are 6 ovoid cement glands. Pomphorhynchus fuhaiensis is similar to Pomphorhynchus laevis but can be distinguished by the number of longitudinal rows of hooks. Pomphorhynchus laevis is armed with 18-20 longitudinal rows of 11-13 hooks, P. fuhaiensis is armed with 15-17 longitudinal rows of 9-12 hooks.

Macracanthorhynchus hirudinaceus in expanding wild boar (Sus scrofa) populations in Eastern Spain.

Prevalence and temporal evolution of the infection by the acanthocephalan Macracanthorhynchus hirudinaceus is studied in the Valencian Community (Eastern Spain), a region only recently fully colonized by the expanding native Eurasian wild boar (Sus scrofa). For 8 years, a total of 1486 wild boars were sampled in order to look for the parasite. The mean prevalence was 20.7% (95% CI, 18.6-22.8; 307/1486). We observed an increasing trend through time, both in the number of wild boars and affected districts. The prevalence of M. hirudinaceus rose in parallel to the annual capture of wild boars, and its presence has been expanding towards the East. A hotspot of M. hirudinaceus is located to the west of the study area, in Muela de Cortes Game Reserve, where 89.6% of the wild boars were positive for the infection, constituting one of the world's highest known prevalence areas.

Case report: Intestinal perforation and secondary peritonitis due to Acanthocephala infection in a black-bellied pangolin (Phataginus tetradactyla).

A case of Acanthocephala infection in a 5-year-old female rehabilitated and released black-bellied pangolin (Phataginus tetradactyla), which was part of a post-release monitoring program of a pangolin research operation in the Central African Republic, is described. This represents the first report of Acanthocephala infection in this species, which lead to intestinal perforation, secondary peritonitis and ultimately to the death of the animal concerned. It is of relevance to alert the pangolin conservation and research community to a so far unreported cause of death. A case history and necropsy findings, as well as preliminary parasite identification and genetic characterization which potentially revealed a new gigantorhynchid taxon are presented.

Frequent infections of mountain stream fish with the amphibian acanthocephalan, Pseudoacanthocephalus toshimai (Acanthocephala: Echinorhynchidae).

Pseudoacanthocephalus toshimai is an intestinal acanthocephalan parasite of amphibians in Hokkaido, the northernmost island of Japan. In this study, common freshwater fish of the families Salmonidae and Cottidae in mountain streams around the Kamikawa basin of Hokkaido were examined for acanthocephalan infections with P. toshimai. A total of 160 salmonids and 14 cottids were caught in 4 streams by bait fishing during summer and autumn seasons of 2019. Adult acanthocephalans were found only from the salmonids, namely, Salvelinus leucomaenis leucomaenis, Salvelinus malma krascheninnikovi, Oncorhynchus masou, and Oncorhynchus mykiss. The maximum prevalence reached 58.1% in S. leucomaenis, but the mean worm burden was at low levels (e.g., 3.1 in S. leucomaenis and 2.2 in S. malma). All of the acanthocephalans were identified to P. toshimai by morphological observation and DNA barcoding. Although the male acanthocephalans became sexually mature, the females never reached the gravid adult stage, suggesting that salmonids are unsuitable or aberrant hosts for P. toshimai. The infected fish were found exclusively from a small stream with bush, in which a large habitat of amphibians is included. Ligidium japonicum, a terrestrial isopod, collected from the habitat was highly infected with cystacanth larvae of P. toshimai. The observation of fish stomach contents directly demonstrated that small salmonids eat L. japonicum. The terrestrial isopods, which are washed away by rain into a stream, seem to be a source of salmonid infections with P. toshimai. The habitat of intermediate hosts should be emphasized in the taxonomy of the closely related genera Acanthocephalus and Pseudoacanthocephalus.

Helminth diversity in Pimelodus blochii Valenciennes, 1840 (Osteichthyes: Pimelodidae) in two Amazon Rivers.

Structure of the helminth community and analyses of helminth population parameters of Pimelodus blochii collected in the Xapuri River in comparison with those in the Acre River were evaluated. Eight adult helminth species were found parasitizing P. blochii in the Acre River: the nematodes Orientatractis moraveci, Rondonia rondoni, Philometroides acreanensis, Cucullanus (Cucculanus) pinai pinai, Procamallanus (Spirocamallanus) pimelodus, Rhadochona acuminata, and Brasilnema sp., and the trematode Dadaytrema oxycephala. For Xapuri's fishes, nine helminth species were found: the nematodes O. moraveci, R. rondoni, C. (C.) pinai pinai, Procamallanus (Spirocamallanus) rarus, P. (S.) pimelodus, R. acuminata, Brasilnema sp., and Cystidicolidae gen. sp., and the trematode D. oxycephala. Nematode and Acanthocephala larvae were also reported. Helminth abundance, prevalence, and diversity were influenced by seasonality and locality (river). The helminth parasites from Acre's fishes formed a subset of the helminth community of the Xapuri's. The results indicate an influence of the environmental characteristics of the rivers on the helminth community structure and diversity. This is the first study of the parasite community of P. blochii in the Xapuri River. The paretheses of (Spirocamallanus) and (S.) should not be in italics all along the text and tables.

Profilicollis chasmagnathi (Acanthocephala) parasitizing freshwater fishes: paratenicity and an exception to the phylogenetic conservatism of the genus?

Polymorphid acanthocephalans are parasites of marine mammals, waterfowl and ichthyophagous birds. Among these, the genus Profilicollis is known to use exclusively decapods as intermediate hosts. Here, we report the first record of living cystacanths of Profilicollis parasitizing the body cavity of a fish host, Oligosarcus jenynsii, inhabiting the freshwater section of an estuarial system, Mar Chiquita coastal lagoon, in south-east Buenos Aires Province, Argentina. In this environment, cystacanths of Profilicollis chasmagnathi have been previously recorded infecting decapod crabs and as transient accidental infections in the gut of some carcinophagous fishes. In the present study, larvae from the crab Neohelice granulata, from the intestine of the estuarine fish Odontesthes argentinensis and from the body cavity of O. jenynsii were morphologically and genetically compared, confirming their identity as P. chasmagnathi, a species characteristic of estuaries and marine coasts along Argentina, Uruguay and Chile. These findings can be interpreted as a possible case of incipient paratenicity for Profilicollis, and a colonization event of freshwater habitats, probably promoted by the highly variable conditions, typical of ecotonal environments. In addition, cystacanths of the genus Polymorphus were also found in O. jenynsii, representing the first record of this genus in Oligosarcus from Argentina.

Description and molecular analysis of an Italian population of Centrorhynchus globo caudatus (Zeder, 1800) Lühe, 1911 (Acanthocephala: Centrorhynchidae) from Falco tinnunculus (Falconidae) and Buteo buteo (Accipitridae).

Centrorhynchus globocaudatus (Zeder, 1800) Lühe, 1911 (Centrorhynchidae) was reported in birds of prey. Our population from Falco tinnunculus Linnaeus (Falconidae) and Buteo buteo Linnaeus (Accipitridae) in northern Italy was morphologically distinct from others described elsewhere. The worms are elongate and cylindrical. Proboscis long, apically truncated and bare, with wider base and variably faint constriction at point of attachment of receptacle. Large anterior hooks well rooted; posterior spiniform hooks with reduced roots; transitional hooks with scutiform roots in-between. Four tubular cement glands extend into prominent ducts overlapping a large Saefftigen's pouch. Bursa large, with sensory plates. Vagina with laterally slit orifice in sub-ventral pit of globular terminal extension. Thick-shelled eggs ovoid without polar prolongation of fertilization membrane. In our specimens, proboscis hooks, receptacle, male reproductive system, and lemnisci especially in males varied in size from those from Ukraine, India, Egypt, Kyrgystan, Russia, Georgia, Armenia and Asian Soviet Republics. Our description of the Italian specimens includes new morphological information supported by scanning electron microscopy and microscope images, molecular analysis and energy dispersive X-ray analysis (EDXA) of hooks. Additional new details of proboscis hook roots, micropores and micropore distribution are described. Metal composition of hooks (EDXA) demonstrated high levels of calcium and phosphorous, and high levels of sulphur in core and cortical layers of eggs. The molecular profile based on sequences of 18S and cytochrome c oxidase 1 genes is also provided, as well as phylogenetic reconstructions including all available sequences of the family Centrorhynchidae, although further sequences are needed in order to clarify their phylogenetic relationships.

Prevalence and genetic diversity of Echinorhynchus gymnocyprii (Acanthocephala: Echinorhynchidae) in schizothoracine fishes (Cyprinidae: Schizothoracinae) in Qinghai-Tibetan Plateau, China.

BACKGROUND: The schizothoracine fishes, an excellent model for several studies, is a dominant fish group of the Qinghai-Tibet Plateau (QTP). However, species populations have rapidly declined due to various factors, and infection with Echinorhynchus gymnocyprii is cited as a possible factor. In the present study, the molecular characteristics of E. gymnocyprii in four species of schizothoracine fishes from the QTP were explored. METHODS: We investigated the infection status of E. gymnocyprii in 156 schizothoracine fishes from the upper Yangtze River, upper Yellow River, and Qinghai Lake in Qinghai Province, China. The complete internal transcribed spacer (ITS) of the ribosomal RNA (rRNA) gene and part of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of 35 E. gymnocyprii isolates from these fishes were sequenced and their characteristics analyzed. In addition, we inferred phylogenetic relationships of the E. gymnocyprii populations based on the rRNA-ITS and cox1 sequences. RESULTS: The total prevalence of E. gymnocyprii in schizothoracine fishes was 57.69% (90/156). However, the prevalence among different species as well as that across the geographical locations of the schizothoracine fishes was significantly different. The results of sequence analysis showed that the four E. gymnocyprii populations from different hosts and regions of Qinghai Province were conspecific, exhibiting rich genetic diversity. Phylogenetic analysis based on rRNA-ITS and cox1 sequences supported the coalescence of branches within E. gymnocyprii; the cox1 gene of E. gymnocyprii populations inferred some geographical associations with water systems. In addition, three species of schizothoracine fishes were recorded as new definitive hosts for E. gymnocyprii. CONCLUSIONS: To the best of our knowledge, this is the first molecular description of E. gymnocyprii populations in schizothoracine fishes from the Qinghai-Tibet Plateau that provides basic data for epidemiological surveillance and control of acanthocephaliasis to protect endemic fish stocks.

Parasites in micromammal fecal pellets throughout the Late Holocene ("Cueva Peligro" paleontological site, Patagonia, Argentina).

Parasite remains in micromammal fecal pellets collected from the paleontological site "Cueva Peligro" (CP 43°40'18"S, 66°24'52"W), Chubut Province, Argentina, were examined. The samples were obtained from two grids, dated between 1220 ± 7014C yr B.P. to modern dates. Fecal pellets were whole processed, rehydrated, homogenized, and examined via light microscopy. Eggs of parasites found were measured and photographed. Fecal pellets belong to one or more insectivore to omnivore unidentified micromammal species, possibly sigmodontine rodents. A high number of helminthes species was recorded (11 species), eight nematodes, two anoplocephalid cestodes and one acanthocephalan species. The sigmodontine-parasite relationship varied throughout the studied period and between studied grids. This is the first time that Gongylonema sp. and Syphacia sp. are reported from ancient times from Patagonia. The obtained results contribute to the knowledge of parasite assemblages associated to native South American sigmodontine rodents and the zoonoses present in the area throughout the lasts 1200 years.

Characterization of the complete mitogenome of Centrorhynchus clitorideus (Meyer, 1931) (Palaeacanthocephala: Centrorhynchidae), the largest mitochondrial genome in Acanthocephala, and its phylogenetic implications.

Species of Centrorhynchus (Polymorphida: Centrorhynchidae) commonly parasitize various falconiform and strigiform birds worldwide. In the present study, the complete mitochondrial (mt) genome sequences of Centrorhynchus clitorideus was sequenced and annotated for the first time based on specimens collected from the little owl Athene noctua (Scopoli) (Strigiformes: Strigidae) in Pakistan. The complete mt genome sequences of C. clitorideus is 15,884 bp in length, and contained 36 genes [two rRNA genes (rrnL and rrnS), 22 tRNA genes and 12 protein-coding genes (PCGs) (lacking atp8)] and two non-coding regions (NCR1 and NCR2), which represents the largest mt genome of acanthocephalan reported so far. In order to assess the systematic position of C. clitorideus and the interrelationship of the family Centrorhynchidae and the other families in order Polymorphida, the phylogenetic tree was constructed using Bayesian inference (BI) based on amino acid sequences of 12 PCGs. Phylogenetic results supported C. clitorideus formed a sister relationship to C. milvus in Centrorhynchidae, which has a sister relationship to the representatives of Polymorphidae + Plagiorhynchidae. Our results revealed the monophyly of Polymorphida and paraphyly of Echinorhynchida in the class Palaeacanthocephala. The validity of the genus Sphaerirostris (Polymorphida: Centrorhynchidae) was also challenged by our phylogenetic results, which seems to be a synonym of Centrorhynchus. Moreover, the present phylogenetic analysis indicated that the family Quadrigyridae and subfamily Pallisentinae (A. cheni and P. celatus) are polyphyletic.

One-sided infections by intestinal parasites in two sympatric porpoises bycaught from the Nemuro Strait of Hokkaido, Japan.

Due to the difficulties and limitations associated with field sampling of marine mammals, quantitative surveys on their parasites are still scarce in Japan. We here report the infection statuses of intestinal parasites in harbor porpoises (n = 34) and Dall's porpoises (n = 10), bycaught between 2014 and 2018 by a bottom set-net fishery in the northern part of the Nemuro Strait, Japan. Necropsies of the harbor porpoises recovered one digenean, Synthesium nipponicum, and two acanthocephalans, Corynosoma sp. and Bolbosoma sp.; no infection was observed in the Dall's porpoises. The dominant parasites were Corynosoma sp. and S. nipponicum, with a prevalence of 73.53 and 64.71% and a mean abundance of 43.88 and 7.38 individuals, respectively. Although the two porpoise-species have a sympatric distribution in this narrow strait, the findings support the existence of trophic-link dependences, which can differentially affect vulnerability to these parasites.

Interannual variation in the metazoan parasite communities of bigeye trevally Caranx sexfasciatus (Pisces, Carangidae).

Parasite communities in Caranx sexfasciatus were characterized and analyzed to determine any interannual variations in structure and/or species composition. In total, 422 C. sexfasciatus were collected from Acapulco Bay, Mexico, between May 2016 and March 2019. Thirty-two taxa of metazoan parasites were identified: five Monogenea, thirteen Digenea, one Acanthocephala, one Cestoda, three Nematoda, seven Copepoda, and two Isopoda. Monogeneans were the most frequent and abundant parasite species in all sampling years. Parasite species richness at the component community level varied significantly from 8 (May 2016) to 25 (March 2019) and was similar to previous reports for other species of Carangidae. The component communities and infracommunities in C. sexfasciatus were characterized by low parasite species numbers, low diversity, and dominance of a single species (the monogenean Neomicrocotyle pacifica). Parasite community structure and species composition varied between sampling years and climatic seasons. Seasonal or local fluctuations in some biotic and abiotic environmental factors probably explain these variations.

TITLE: Variation interannuelle des communautés de parasites métazoaires de la carangue à gros yeux Caranx sexfasciatus (Pisces, Carangidae). ABSTRACT: Les communautés de parasites de Caranx sexfasciatus ont été caractérisées et analysées afin de déterminer si elles connaissent des variations interannuelles dans la structure et/ou la composition des espèces. Au total, 422 C. sexfasciatus ont été collectés dans la baie d'Acapulco, au Mexique, entre mai 2016 et mars 2019. Trente-deux taxons de parasites métazoaires ont été identifiés : cinq Monogenea, treize Digenea, un Acanthocephala, un Cestoda, trois Nematoda, sept Copepoda et deux Isopoda. Les monogènes étaient les espèces de parasites les plus fréquentes et les plus abondantes au cours de toutes les années d'échantillonnage. La richesse en espèces de parasites au niveau de la communauté des composants variait considérablement de 8 (mai 2016) à 25 (mars 2019) et était similaire aux rapports précédents pour d'autres espèces de Carangidae. Les communautés et infracommunautés de C. sexfasciatus étaient caractérisées par un faible nombre d'espèces de parasites, une faible diversité et la dominance d'une seule espèce (le monogène Neomicrocotyle pacifica). La structure des communautés de parasites et la composition des espèces variaient entre les années d'échantillonnage et les saisons climatiques. Les fluctuations saisonnières ou locales de certains facteurs environnementaux biotiques et abiotiques expliquent probablement ces variations.

A new species of Pseudoacanthocephalus (Acanthocephala: Echinorhynchidae) from the guttural toad, Sclerophrys gutturalis (Bufonidae), introduced into Mauritius, with comments on the implications of the introductions of toads and their parasites into the UK.

Pseudoacanthocephalus goodmani n. sp. is described from faecal pellets collected from Sclerophrys gutturalis (Power, 1927), the guttural toad. The species is characterized by a suite of characters, including a proboscis armature of 14-18 longitudinal rows of 4-6 hooks with simple roots, lemnisci longer than the proboscis receptacle, equatorial testes, a cluster of elongated cement glands and eggs without polar prolongations of the middle membrane 72.6-85.8 long. The toad had been accidentally translocated from Mauritius to the UK in a tourist's luggage and survived a washing machine cycle. The guttural toad was introduced into Mauritius from South Africa in 1922 and the cane toad, Rhinella marina (Linneaus, 1758), from South America, between 1936 and 1938. It seems most likely, therefore, that P. goodmani was introduced, with the guttural toad, from South Africa. The cane toad is host to the similar species, Pseudoacanthocephalus lutzi, from the Americas, but P. lutzi has not been recorded from places where the cane toad has been introduced elsewhere. Clearly, the guttural toad is a hardy and adaptable species, although it seems unlikely that it could become established in Northern Europe. Nevertheless, any accidental translocation of hosts poses the potential risk of introducing unwanted pathogens into the environment and should be guarded against.

Using lizards to evaluate the influence of average abundance on the variance of endoparasites in semiarid areas: dispersion and assemblage structure.

The distribution of parasites within host populations and communities, and the mechanisms responsible for these patterns, are poorly understood aspects of wildlife parasitology. Here, we evaluate the influence of the average abundance of endoparasite variance, using endoparasites of lizards from the Caatinga domain (semiarid region), north-eastern Brazil. We hypothesized that, due to the high number of generalist endoparasite species, they may occur randomly throughout host populations in an aggregate pattern. In addition, we evaluated the degree to which sample variance is influenced by the average abundance of endoparasite species, patterns of co-occurrence and dominance among endoparasite species and similarities between abundance and the richness of endoparasite infracommunities in several host species. Between September 2015 and February 2016, 2141 lizards (1233 infected) from 16 species were collected from six Caatinga areas. In total, 25,687 endoparasites were collected, which belonged to 13 species including nematodes, pentastomids, cestodes, trematodes and acanthocephalans. Parasite-host associations documented here included 39 newly identified interactions. Endoparasites occurred in a typical aggregate pattern of distribution within their hosts; there was no measurable preference related to the acquisition of hosts by endoparasites. Despite the new records, endoparasites found were commonly associated with lizards in Caatinga environments, which may reflect fauna composed of generalist endoparasite species.

Morphological comparison of genetically differentiated Polymorphus cf. minutus types.

In the present study, we analyzed the morphology of three genetic types of the bird-infecting acanthocephalan Polymorphus cf. minutus (PspT1, PspT2, PspT3), mainly based on the cystacanth-stage obtained from amphipods (Gammarus fossarum, Gammarus pulex, Gammarus roeselii, Echinogammarus spp.). Males and females were pooled as there was no considerable difference between the sexes concerning the hook measurements. Additionally, we conducted a laboratory infection of one domestic duck for each Polymorphus type, to compare their performance and localization in this host species, and to obtain adult specimens for morphological comparison. The recovery rate from the ducks 4 weeks after infection was 16% for PspT1, 23.8% for PspT2, and 25% for PspT3. The adult worms were gravid, and the females contained mature eggs. Hook size did not differ considerably between cystacanths and adults of the respective type. The three Polymorphus types could be distinguished based on the cystacanth stage by a linear discriminant analysis that included hook measurements, proboscis length, proboscis width, and number of longitudinal hook rows and hooks per row. Furthermore, PspT3 was more different from PspT1 and PspT2 than the latter types from each other. Mainly the number of longitudinal hook rows differed in PspT3 from the existing descriptions of P. minutus (mainly 14 vs. mainly 16 rows). Potentially, PspT3 could be a non-indigenous parasite that was introduced with G. roeselii and that adapted to use the indigenous G. pulex as a host, while PspT2 might have been introduced to central Europe together with Echinogammarus spp.

Long-term temporal variation in the parasite community structure of metazoans of Pimelodus blochii (Pimelodidae), a catfish from the Brazilian Amazon.

The Amazon represents one of the most complex biomes in the world; however, the temporal variations in parasite community structure of fishes inhabiting this region remain poorly understood. Therefore, processes generating such variations are still unknown. The present study evaluated the long-term temporal variation of community structure of metazoan parasites of Pimelodus blochii collected in Iaco River, State of Acre (Southwestern Brazilian Amazon). A total of 196 parasites were collected over a 6-year period (2012-2017). Twenty-four different taxa of parasites were found, of which 5 Monogenea, 11 Nematoda, 3 Digenea, 1 Acanthocephala, 1 Cestoda, and 3 Crustacea. The overall species richness ranged from 4 in 2012 to 17 in 2016, in which nematodes (larvae and adults) showed higher numerical dominance, diversity, and species richness. However, the annual species richness was similar between the study years, except in 2016, where it showed a distinctly higher value. The overall parasite diversity was also different in 2012 and 2016, whereas the overall abundance differed in 2013 and 2017. The prevalence and abundance of some infracommunities of parasites varied over time. The temporal changes in the parasite community structure of P. blochii are probably related to variations in host-related features, i.e., body size and shift in diet composition as well as to the occurrence of parasites with distinct life history and biology (mainly monogeneans, digeneans, and nematodes). This is the first evaluation of a long-term temporal variation in the structure of the parasite community in fish from the Amazon.

Distribution patterns of two species of Corynosoma (Acanthocephala: Polymorphidae) in fishes from Southwestern Atlantic.

Corynosoma australe and C. cetaceum are the most frequently reported acanthocephalans in fish from the Argentine Sea, particularly in central and northern areas. Their definitive hosts are otariids and odontocete cetaceans, respectively. The low specificity of these larvae, in combination with high infective capability and long survival periods in fish, make them potentially good biological markers for stocks and other biological features of their fish hosts. In order to determine the distribution patterns of these species and their determining factors, a large dataset composed by newly collected fish samples, published and unpublished data from previous studies by the authors in the region were analysed in relation to host and environmental variables. The complete dataset comprised a total of 5084 fish, belonging to 29 species distributed in 21 families and 9 orders. Host size and trophic habits arose as the main determinants of abundance for both species of Corynosoma, showing higher abundances on larger fish and on higher trophic levels, as it is usual for trophically transmitted parasites. Biogeographic province and depth (indirectly representing the temperature of water) were the main drivers of the spatial distribution, displaying a latitudinal pattern associated to the temperature clines created by the interaction of Malvinas and Brazil currents, determining a decrease in abundance southwards and towards the deeper areas. No patterns were found regarding the distribution of definitive hosts. The knowledge of these distribution patterns of Corynosoma spp. in fish at regional scale, as well as of their causes, provides useful information to design management and conservation policies thus contributing to maintain the full and sustainable productivity of fisheries.

Gastrointestinal and external parasites of the Variable hawk Geranoaetus polyosoma (Accipitriformes: Accipitridae) in Chile.

Information about parasites associated with diurnal raptors from Chile is scarce. Between 2006 and 2017, a total of 15 specimens of the Variable hawk, Geranoaetus polyosoma (Quoy & Gaimard, 1824) were collected, 14 of them from different localities in the Biobío region and one specimen from the Valparaíso region. An external examination of the plumage was made to collect ectoparasites, and necropsies were performed, focusing primarily on the gastrointestinal tract. Chewing lice (Phthiraptera) were found on five (33.3%) of the birds corresponding to three species: 97 specimens of Degeeriella fulva (Giebel, 1874), six specimens of Colpocephalum turbinatum Denny, 1842 and nine belonging to an unidentified species of the genus Craspedorrhynchus Kéler, 1938. Endoparasites found in three (20%) of the birds included round worms (Nematoda) of the genus Procyrnea Chabaud, 1958, and spiny-headed worms (Acanthocephala) of the genus Centrorhynchus Lühe, 1911. The species Colpocephalum turbinatum and the genera: Craspedorrhynchus sp., Procyrnea sp. and Centrorhynchus sp. are new records for the Variable hawk.