Cryptocotyle Research Articles

The structure of the Cryptocotyle lingua miracidium (Digenea: Opisthorchiidae)

In the course of Digenea evolution the transitions to a passive strategy of infection of the first intermediate host occurred multiple times. In these cases, miracidia – ciliated larvae – relinquished their role as active seekers for a suitable snail host and began relying on the chance of being accidently ingested by it. The structural changes resulting from these transitions are diverse, but the majority of them are reductive. In this study we present our ultrastructural survey on the opisthorchioid Cryptocotyle lingua miracidium. The transition to passivity led to extensive reduction in almost all somatic elements of the larva: only four epithelial plates cover its body; just a single nervous cell, a single protonephridium and a single longitudinally-oriented muscle cell have been found in this miracidium. Several undifferentiated cells comprise the germinal material of the larva. The greatest part of its body is occupied by three glandular elements. The position of these glands is consistent within Opisthorchioidea and strikingly corresponds to that of some of the optically studied miracidia of Plagiorchioidea. This similarity is suspicious, because the C. lingua larva appeared to differ vastly from other ultrastructurally described passive miracidia. Here we create a basis for the future comparison of the miracidia of Opisthorchioidea and Plagiorchioidea, expecting the ultrastructural data on the latter to be published someday.

Re-evaluation of certain aspects of the EFSA Scientific Opinion of April 2010 on risk assessment of parasites in fishery products, based on new scientific data. Part 1: ToRs1-3.

Surveillance data published since 2010, although limited, showed that there is no evidence of zoonotic parasite infection in market quality Atlantic salmon, marine rainbow trout, gilthead seabream, turbot, meagre, Atlantic halibut, common carp and European catfish. No studies were found for greater amberjack, brown trout, African catfish, European eel and pikeperch. Anisakis pegreffii, A. simplex (s. s.) and Cryptocotyle lingua were found in European seabass, Atlantic bluefin tuna and/or cod, and Pseudamphistomum truncatum and Paracoenogonimus ovatus in tench, produced in open offshore cages or flow-through ponds or tanks. It is almost certain that fish produced in closed recirculating aquaculture systems (RAS) or flow-through facilities with filtered water intake and exclusively fed heat-treated feed are free of zoonotic parasites. Since the last EFSA opinion, the UV-press and artificial digestion methods have been developed into ISO standards to detect parasites in fish, while new UV-scanning, optical, molecular and OMICs technologies and methodologies have been developed for the detection, visualisation, isolation and/or identification of zoonotic parasites in fish. Freezing and heating continue to be the most efficient methods to kill parasites in fishery products. High-pressure processing may be suitable for some specific products. Pulsed electric field is a promising technology although further development is needed. Ultrasound treatments were not effective. Traditional dry salting of anchovies successfully inactivated Anisakis. Studies on other traditional processes - air-drying and double salting (brine salting plus dry salting) - suggest that anisakids are successfully inactivated, but more data covering these and other parasites in more fish species and products is required to determine if these processes are always effective. Marinade combinations with anchovies have not effectively inactivated anisakids. Natural products, essential oils and plant extracts, may kill parasites but safety and organoleptic data are lacking. Advanced processing techniques for intelligent gutting and trimming are being developed to remove parasites from fish.

Effect of trematode infection on cardiac activity of marine gastropod Littorina littorea in situ and under laboratory conditions.

Physiological mechanisms underlying relationships between the trematode parthenitae and their molluscan hosts are poorly understood. In this study, we estimated the cardiac function of gastropods Littorina littorea L. infected with Himasthla elongata and Cryptocotyle lingua under laboratory conditions and in situ. The heart rate (HR) of the infected periwinkles was significantly lower than in the uninfected ones. HR of uninfected periwinkles in the natural environment followed a clear tidal pattern, with high values at high tide and low values at low tide. However, HR in most of the infected molluscs did not follow this rhythm. The decrease in HR was more pronounced in the periwinkles infected with C. lingua than with H. elongata. Thus, infection with C. lingua had a greater effect on the physiology and metabolic rate of periwinkles than infection with H. elongata.

Neuronal gene expression in two generations of the marine parasitic worm, Cryptocotyle lingua

Trematodes, or flukes, undergo intricate anatomical and behavioral transformations during their life cycle, yet the functional changes in their nervous system remain poorly understood. We investigated the molecular basis of nervous system function in Cryptocotyle lingua, a species of relevance for fisheries. Transcriptomic analysis revealed a streamlined molecular toolkit with the absence of key signaling pathways and ion channels. Notably, we observed the loss of nitric oxide synthase across the Platyhelminthes. Furthermore, we identified upregulated neuronal genes in dispersal larvae, including those involved in aminergic pathways, synaptic vesicle trafficking, TRPA channels, and surprisingly nitric oxide receptors. Using neuronal markers and in situ hybridization, we hypothesized their functional relevance to larval adaptations and host-finding strategies. Additionally, employing a behavior quantification toolkit, we assessed cercaria motility, facilitating further investigations into the behavior and physiology of parasitic flatworms. This study enhances our understanding of trematode neurobiology and provides insights for targeted antiparasitic strategies.

Unveiling novel RNA viruses in trematodes parasitizing common periwinkle: Implications for host-parasite interactions

This study characterized novel RNA viruses, parasites of parasites, or hyperparasites identified during transcriptomic analyses of two trematode species, Cryptocotyle lingua and Himasthla elongata, infecting a sea snail, Littorina littorea. According to the viral genome structures and phylogenetic analysis, Cryptolin alternavirus (ClRNAV1), Cryptolin calicivirus (ClRNAV2) and Himastelon rhabdovirus 1 (HeRNAV1) were respectively classified within the families Alternaviridae, Caliciviridae and Rhabdoviridae. They replicate species-specifically in two studied phases of trematode live cycle: intramolluscan parthenogenetic rediae and free-swimming cercariae. ClRNAV1 showed significantly higher expression in C. lingua cercariae relative to rediae. HeRNAV1′s similarity to rabies viruses raises questions about its potential effects on the nervous system of H. elongata. This 'trematode rabies' could enable the use of genetically modified viruses for developing new methods to control the spread and intensity of diseases caused by trematodes.

Helminth Parasites of Yellow-Legged Gull Larus michahellis (Charadriiformes) from Bursa, Turkey

The yellow-legged gull, Larus michahellis, is a common gull that exists in Europe, the Middle East, and North Africa. Their broad diet makes them especially susceptible to a variety of helminths. We conducted a survey of intestinal helminths of L. michahellis to determine the diversity of intestinal parasites. Thirty-five yellow-legged gulls were necropsied, and helminths were examined via light microscopy. Twenty-three of 35 (65%) of hosts examined were infected with the following helminths: 6 Digenea species (Acanthotrema armata, Brachylaima aspersae, Cryptocotyle lingua, Diplostomum spathaceum, Knipowitschiatrema sp., and Stephanoprora denticulata); 5 Cestode species (Alcotaenia microcantha, Diphyllobothrium dentriticum, Microsomacanthus ductilis, Monopylidium galbulae, and Tetrabothrius erostris); and 2 Nematode species (Contracaecum rudolphii and Synhimanthus sp.). Herein, the intestinal parasite diversity of yellow-legged gulls from Turkey is reported, and new geographical records are documented.

New Data on Pipefishes' and Seahorse's Endohelminths Off Crimean Coasts of The Black Sea.

SummaryA total of 357 Syngnathidae fishes (Syngnathus abaster Risso, 1827, S. typhle Linnaeus, 1758 and Hippocampus hippocampus (Linnaeus, 1758) caught in different habitats along Crimean Black Sea shelf were examined for presence of endohelminths and revealed to be hosts of 15 helminth species. The fishes are second intermediate hosts for five “birds’” digenean species and nematodes (larvae of three species and immature adults of one more species) completing life-cycles in waterbirds and fish; for two acanthocephalans and three cestodes larvae ending development in fish. We suggest, basing on data on feeding of the Black Sea predatory fish and waterbirds, that Syngnathid fishes are paratenic hosts in parasitic systems of most cestodes, nematodes and acanthocephalans. All the trematodes found are generalists at metacercarial stage; specialists Timoniella imbutiformis and Aphallus tubarium use Syngnathidae as definitive hosts. Cestodes, nematodes as well as acanthocephalans found are generalists, too. Based on infection indices, S. typhle are main final host and H. hippocampus are main 2nd intermediate hosts for T. imbutiformis; Syngnathids are accidental hosts for other trematodes as well as for all the cestodes, nematodes and acanthocephalans. Cryptocotyle concava and Pygidiopsis genata are important as Syngnathid fishes’ threats, especially in marine protected aquatoria, being potential agents of “black spot disease”.

Absence of zoonotic parasites in salmonid aquaculture in Denmark: Causes and consequences

A parasitological investigation of Danish farmed freshwater (180 fish) and marine rainbow trout (170 fish), Oncorhynchus mykiss , was performed with an emphasis on the occurrence of zoonotic parasites. Reliability of the parasitological methods applied was assessed by examining fish from a stock of wild Atlantic cod Gadus morhua caught in the Sound (Øresund). While wild fish carried a number of zoonotic parasites, we found that farmed fish, both in the fresh and marine environment, were free of these parasites. Non-zoonotic trout parasites found were eye-flukes Diplostomum paracaudum, D. pseudospathaceum and Eubothrium crassum in maricultured rainbow trout. The acanthocephalan Echinorhynchus truttae and Diplostomum sp. were found in freshwater trout. In contrast, wild cod were infected with five different nematode species ( Anisakis simplex , Contracaecum osculatum , Pseudoterranova decipiens , Hysterothylacium aduncum , Cucullanus cirratus ), three trematode species ( Lepidapedon elongatum , Cryptocotyle lingua , Hemiurus communis ), one copepod species ( Lernaeocera branchialis ) and one myxozoan ( Myxobolus aeglefini ). The risk factors associated with aquaculture production in an infectious aquatic environment are analyzed and reasons for absence of zoonotic parasites in aquacultured trout are pinpointed. Based on the analysis recommendations for management practices securing parasite freedom in aquacultured fish are given. • Salmonid aquaculture in Denmark is free from zoonotic parasites. • Fish parasitological methods are validated by examination of wild fish. • Risk factors associated with aquaculture production are evaluated. • Recommendations for prevention of zoonotic parasite introduction are presented.

Cryptocotyle lingua

This datasheet on Cryptocotyle lingua covers Identity, Distribution, Hosts/Species Affected.

Cryptocotyle lata (Trematoda: Heterophyidae) Adult from a Korean Raccoon Dog, Nyctereutes procyonoides koreensis.

Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular characteristics, the flukes were identified to Cryptocotyle lata. The adult C. lata were minute, transparent, pentagonal, 522 μm long by 425 μm wide. Ceca extended into post-testicular region. Ventrogenital sac elliptical, 79 μm by 87 μm with genital pore and ventral sucker. Two testes semielliptical and slightly lobed, located in the posterior region, right testis 173 μm by 155 μm, left testis 130 μm by 134 μm. In a phylogenetic tree, the fluke specimen of this study was grouped with C. lata divergent from Cryptocotyle lingua. We report here N. procyonoides koreensis first as a natural definitive host of C. lata.

Host and geographic differences in prevalence and diversity of gastrointestinal helminths of foxes (Vulpes vulpes), coyotes (Canis latrans) and wolves (Canis lupus) in Québec, Canada.

Wild canids are hosts to a wide range of parasites and can play a role in transmission of zoonoses. As many parasites are transmitted through food webs, and wild canids are at high trophic levels, parasite prevalence and diversity in wild canids can serve as excellent indicators of ecosystem health. Our main objectives were to update knowledge on the composition of gastrointestinal helminths in wild canids from Québec, Canada, and to describe differences in parasite prevalence and diversity among canid species and regions. Hunters and trappers provided whole carcasses of red foxes (Vulpes vulpes) (N = 176), and intestinal tracts of coyotes (Canis latrans) (N = 77) and gray wolves (Canis lupus) (N = 23) harvested for non-research purposes over the winter of 2016–2017. A modified Stoll's centrifugation sucrose flotation on feces of 250 wild canids was used, and eggs of one family and eight genera of parasitic helminths were recovered: diphyllobothriids, Taenia/Echinococcus spp., Capillaria spp., Toxascaris sp., Toxocara sp., Trichuris sp., Uncinaria sp., and Metorchis sp. Adult Taenia spp. cestodes were recovered from 61 of 276 (22%) canids. Six different species (T. hydatigena, T. twitchelli, T. crassiceps, T. polyacantha, T. krabbei, and T. pisiformis-“like”) were differentiated based on DNA sequenced from 65 individual adult cestodes using primers for the nicotinamide adenosine dinucleotide dehydrogenase subunit 1 (ND1) and cytochrome c oxidase subunit 1 (CO1) mitochondrial DNA loci. Alaria sp. trematodes infected 89 of 276 canids (32%). A subset were identified as A. americana at the CO1 locus. The marine trematode Cryptocotyle lingua was reported for the first time in foxes in the province of Québec. These results help us understand more fully the predator-prey relationships within this group of canids. This baseline data in regional parasite prevalence and intensity is critical in order to detect future changes following ecological disturbances due to climate and landscape alterations.

Morphological and molecular identification of Cryptocotyle lingua metacercariae isolated from Atlantic cod (Gadus morhua) from Danish seas and whiting (Merlangius merlangus) from the English Channel

Trematode larvae (metacercariae) causing black spot disease occur frequently in gills, fins, skin and the superficial muscle layers of marine fish. Species within the genus Cryptocotyle Lühe, 1899 are frequently associated with this disease. Descriptions of the metacercarial stage are relatively limited and none has hitherto been reported from fish from the English Channel. The present study reports the morphological and molecular identifications of encysted black spot-inducing parasites from whiting (Merlangius merlangus) and Atlantic cod (Gadus morhua) caught respectively from the north coast of France (English Channel) and from Danish sea waters. Metacercariae were characterised morphologically based on microscopic observations and molecularly using Sanger sequencing of fragments of the mitochondrial cox1 gene and rDNA ITS region. Morphological data were compared with available data in the literature. Phylogenetic trees including reference sequences were built to confirm morphological and molecular identifications. This survey constitutes the first description of C. lingua metacercariae in the English Channel ecosystems.

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.

Intestinal Flukes Recovered from a Herring Gull, Larus argentatus, in the Republic of Korea.

Trematode specimens were collected from the intestine of a herring gull, Larus argentatus, which was found in a critical condition on the shore of a small island (Yubu-do, Seocheon-gun, Chungcheongnam-do) located at the western coast of the Korean peninsula. Total 11 specimens of intestinal flukes, including 3 Cryptocotyle lingua (Heterophyidae), 1 Himasthla alincia (Echinostomatidae), 5 Cardiocephaloides medioconiger (Strigeidae), and 2 Diplostomum spathaceum (Diplostomidae), were recovered. C. lingua was morphologically characterized by the presence of a large ventrogenital apparatus and 2 obliquely tandem testes. H. alincia had an elongated body and a head collar equipped with 31 collar spines. C. medioconiger had a bisegmented body and a voluminous copulatory bursa containing the seminal vesicle and ejaculatory duct. D. spathaceum also had a bisegmented body and its vitellaria extended up to the anterior border of the tribocytic organ. It is of note that C. lingua is potentially zoonotic that can occur in birds and humans. Three of them, i.e., C. lingua, C. medioconiger, and D. spathaceum, are new trematode fauna in Korea. Studies on trematode fauna of migratory birds should be continued in Korea.

Description of a new species, Cryptocotyle lata sp. nov., and discussion of the phylogenetic relationships in Opisthorchioidea

Adult Cryptocotyle lata sp. nov. worms were obtained from experimental studies. In the Russian southern Far East, the life cycle of this parasite is carried out using freshwater snails (Boreoelona ussuriensis), freshwater fish, and birds as the first intermediate, second intermediate, and definitive hosts, respectively. The morphological indices of C. lata sp. nov. are closest to Cryptocotyle concava; however, these two species differ in terms of their sizes of body, oral and ventral suckers, eggs, and the shape of their testes and ovaries. Analysis of the life cycles of the Cryptocotyle representatives suggested that C. concava were at least two cryptic species, one of which circulates using brackish water Hydrobia snails, and the other using freshwater Amnicola snails as the first intermediate hosts. Molecular data (i.e., the 28S gene and the second internal transcribed spacer (ITS2) of rDNA) were used to analyze the phylogenetic relationships of C. lata sp. nov. and other representatives of Opisthorchioidea. The long repeats and secondary structure of the ITS1 region were studied. Representatives of the Opisthorchiidae and several species from Heterophyidae (including the genus Cryptocotyle) were found to have molecular features that suggested that these species belonged to Opisthorchiidae. At the same time, the genetic relatedness of worms, which are united in common clusters on phylogenetic trees, is consistent with the use of the first intermediate hosts from different taxonomic groups in their life cycles; namely, snails of the Truncatelloidea are hosts of trematodes from a cluster with Opisthorchiidae and a number species of the family Heterophyidae, while snails of the Cerithioidea are hosts of worms from a cluster that includes only the Heterophyidae. In addition, the results of genetic studies indicate that Clonorchis sinensis, Metorchis ussuriensis, Metorchis bilis, Metorchis xanthosomus, and Metorchis orientalis should be included in the genus Opisthorchis.

Morphological framework for attachment and locomotion in several Digenea of the families Microphallidae and Heterophyidae.

Digenea usually use ventral sucker for sustainable attachment within intestine of their definitive vertebrate host. However, if the ventral sucker is absent or poorly developed, the means of attachment are unclear. We investigated attachment and locomotion in such digeneans: three species of the family Microphallidae (Microphallus piriformes, M. pygmaeus, and Levinseniella brachysoma) and two species of the family Heterophyidae (Cryptocotyle concava and C. lingua). Their tegumental spines and musculature were described with use of fluorescent actin staining, confocal microscopy, and scanning electron microscopy. Locomotion of living worms was observed and recorded. Wide serrated tegumental spines probably play the main role in attachment. Their firm contact with the host mucosa may be provided by the action of the ventral concavity-when the entire body or its part acts as a sucker. Dorsoventral muscle bundles act like radial musculature of the sucker generating negative pressure in the ventral concavity. The solid layer of longitudinal muscle fibers on the ventral body surface provides support for the bottom of the ventral concavity. In all microphallids, a U-shaped arrangement of body wall musculature (mostly originating from longitudinal fibers) outlines posterior part of the ventral concavity ridge. In all the studied species, tegumental spines, body wall musculature, and dorsoventral muscle bundles are better developed in the forebody which moves more actively than the hindbody.

Age and serotonin effects on locomotion in marine trematode cercariae

The effect of serotonin solutions on the locomotor activity of cercariae with different swimming patterns, Cryptocotyle lingua and Himasthla elongate, was investigated during their lifespan using motion track analysis and a frame-by-frame count of behavioral elements. Serotonin caused a noticeable alteration of several locomotion parameters in both species studied, while the activity per se decreased significantly with age. In intermittently swimming C. lingua cercariae, serotonin induced an increase in the frequency of active swimming phases (spurts) without significant changes in the duration and velocity of the spurts themselves. In continuously swimming H. elongata cercariae, serotonin increased the number of stops during the first hour after the emission from the host mollusk under a constant average swimming velocity. Immunocytochemical visualization of serotonin revealed a decline in its level with age (time after emission) and different dynamics of this process in neurons located in the tail and body of C. lingua cercariae. The data are interpreted in the light of the modulatory role of serotonin known for other animals.

Trematode fauna (Platyhelminthes: Digenea) of some sea ducks wintering on the southern Baltic coast (NW Poland) – a general comparison

ABSTRACTThe common scoter Melanitta nigra, velvet scoter M. fusca and long-tailed duck Clangula hyemalis (Aves: Anatidae) are among the more abundant sea ducks on the southern coast of the Baltic in winter, but their parasitic trematode fauna (Platyhelminthes, Digenea) in this region is little known. The aim of this study, conducted in 2007–2009, was a general comparison of the trematode fauna of these ducks in NW Poland. The prevalence and intensity of trematode infection were 68.3% and 119.9 in common scoter (101 examined), 77.6% and 13.1 in velvet scoter (58 examined) and 70.6% and 23.7 in long-tailed duck (68 examined). The following trematodes were found: Diplostomum pungitii, Apatemon gracilis, Australapatemon minor, Typhlocoelum sisowi, Echinochasmus spinulosus, Echinoparyphium recurvatum, Psilostomum brevicolle, Psilotrema simillimum, Catatropis verrucosa, Notocotylus attenuatus, N. gibbus, Paramonostomum alveatum, Prosthogonimus ovatus, Levinseniella propinqua, Gymnophallus bursicola and Cryptocotyle concava. The common scoter differs from the velvet scoter and long-tailed duck in its statistically significantly higher prevalence of G. bursicola; from long-tailed duck in its higher prevalence and greater intensity of infection with P. alveatum; and from velvet scoter in its greater intensity of infection with C. concava. The velvet scoter is distinguished from the long-tailed duck by its greater intensity of infection with P. brevicolle, lower prevalence of L. propinqua and lower intensity of infection with C. concava. Links between the differences found and the biology and ecology of the hosts, as well as the means of transmission of the parasites, are also discussed.

Molecular Cytogenetics in Digenean Parasites: Linked and Unlinked Major and 5S rDNAs, B Chromosomes and Karyotype Diversification

Digenetic trematodes are the largest group of internal metazoan parasites, but their chromosomes are poorly studied. Although chromosome numbers and/or karyotypes are known for about 300 of the 18,000 described species, molecular cytogenetic knowledge is mostly limited to the mapping of telomeric sequences and/or of major rDNA clusters in 9 species. In this work we mapped major and 5S rDNA clusters and telomeric sequences in chromosomes of Bucephalus minimus, B. australis, Prosorhynchoides carvajali (Bucephaloidea), Monascus filiformis (Gymnophalloidea), Parorchis acanthus (Echinostomatoidea), Cryptocotyle lingua (Opisthorchioidea), Cercaria longicaudata, Monorchis parvus (Monorchioidea), Diphterostomum brusinae, and Bacciger bacciger (Microphalloidea). Whilst single major and minor rDNA clusters were mapped to different chromosome pairs in B. minimus and P. acanthus, overlapping signals were detected on a single chromosome pair in the remaining taxa. FISH experiments using major rDNA and telomeric probes clearly demonstrated the presence of highly stretched NORs in most of the digenean taxa analyzed. B chromosomes were detected in the B. bacciger samples hosted by Ruditapes decussatus. Although the cercariae specimens obtained from Donax trunculus, Tellina tenuis, and R. decussatus were in agreement with B. bacciger, their karyotypes showed striking morphological differences in agreement with the proposed assignation of these cercariae to different species of the genus Bacciger. Results are discussed in comparison with previous data on digenean chromosomes.

The Parasite Fauna of the Gyrfalcon (Falco rusticolus) in Iceland.

We examined 46 Gyrfalcon (Falco rusticolus) carcasses from Iceland for parasites, including 29 first-year birds and 17 second-year birds and older. Endoparasites observed were the trematodes Cryptocotyle lingua (prevalence 8%), Cryptocotyle concavum (4%), and Strigea sp. (8%); the cestode Mesocestoides sp. (27%); and the nematodes Eucoleus contortus (76%) and Serratospiculum guttatum (7%). Ectoparasites included the astigmatan mite Dubininia accipitrina (47%), a mesostigmatan rhynonyssid mite (4%), the tick Ixodes caledonicus (20%), the mallophagans Degeeriella rufa (90%) and Nosopon lucidum (7%), the flea Ceratophyllus vagabundus (7%), and the louse fly Ornithomya chloropus (7%). Cryptocotyle lingua, C. concavum, S. guttatum, D. accipitrina, I. caledonicus, and N. lucidum are new host records. Of the five most common parasites (prevalence ≥ 20%) only Mesocestoides sp. showed a significant age relationship, being more prevalent in adult falcons (P = 0.021). Eucoleus contortus was also more prevalent in adults with marginal statistical significance (P = 0.058). Frounce, caused by E. contortus (possibly also by Trichomonas gallinae, which was not searched for in the survey) was highly prevalent (43%), but did not show a relationship with host age (P = 0.210). Birds with frounce were in poorer body condition than healthy birds (P = 0.015).