Clinical, histopathological and phylogenetic analysis of Myxobolus lentisturalis (Myxozoa: Myxobolidae) infecting the musculature of farmed population of goldfish (Carassius auratus) in Iran: 2021-2022.

There is a claimed increase in the global prevalence and incidence of emerging diseases observed in many organisms. Myxozoa represents an essential group of metazoan parasites that hold both economic and ecological significance. In the current study, 1% of the fish population at two commercial goldfish (Carassius auratus) farms in Tehran and Ghom province, Iran, developed cavitating muscular lesions resembling humps in February 2021 and January 2022. Fish displaying pathological abnormalities were transported to the Ornamental Fish Clinic and subjected to clinical examination. Light microscopy was subsequently used to examine wet smears of skin and gills, as well as whitish exudate. In addition, tissue homogenates were collected for more precise identification and molecular confirmation. The study discovered that individuals from the goldfish farms were infected with the pathogenic myxozoan Myxobolus lentisuturalis, which caused significant damage to the epaxial muscles. The spores collected from the humps had a lack of uniformity and were primarily ellipsoidal in shape. Histopathological analysis also revealed parasites in various stages of development, such as plasmodia and spores, as well as inflammatory cell infiltration (macrophage, giant cell and lymphoplasmacytic infiltration) between skeletal muscle fibers. Phylogenetic analysis of M. lentisuturalis was performed by using MEGA 11 and the maximum likelihood method. M. lentisuturalis is a myxozoan parasite that has been sparsely recorded and lacks widespread recognition. The current study is the first clinical, histopathological, and molecular characterization of M. lentisuturalis isolated from the skeletal musculature of goldfish (C. auratus) in Iran.

Black sea bass are a host in the developmental cycle of Lernaeenicus radiatus (Copepoda: Pennellidae): insights into parasite morphology, gill pathology and genetics.

Lernaeenicus radiatus, a mesoparasitic pennellid copepod, has long been known in the northwest Atlantic with metamorphosed females infecting the muscle of marine fish. The study herein is the first to identify a definitive first host, black sea bass Centropristis striata, for L. radiatus supporting larval development to adults and sexual reproduction in the gills. This finding suggests a two-host life cycle for L. radiatus, with black sea bass as the first host. Heavy infections in the gill were associated with considerable pathology related to a unique and invasive attachment process that penetrated the gill and selectively attached to the gill filament cartilage. The morphology of the developing copepod was highly conserved with that of a related pennellid copepod, Lernaeocera branchialis, though was distinguished by the attachment process, unique pigmentation and other morphologic features described herein. Sequencing the small and large subunits of the ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes demonstrated L. radiatus to share closer identities with Lernaeocera and Haemobaphes spp. pennellid copepods rather than other Lernaeenicus spp. available in GenBank to date. Taxonomy of L. radiatus is discussed in relation to life cycles, tissue tropism, morphology and genetics of other closely related pennellid copepods.

Field study indicating susceptibility differences between salmonid species and their lineages to proliferative kidney disease.

Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea) is the causative agent of proliferative kidney disease (PKD), which affects both wild and farmed salmonid fish. The objective of this study was to outline differences in susceptibility to PKD in different salmonid species, hybrids and breeding lineages. Susceptibility to T. bryosalmonae infection was established based on cumulative mortality, pathological findings and detection of T. bryosalmonae in the kidney using immunohistochemistry and molecular methods. Determination of pure and hybrid individuals of different species in the genus Salvelinus, and dissimilarity of rainbow trout lineages, was performed using traditional polymerase chain reaction (PCR) and microsatellite analyses. Rainbow trout displayed higher disease severity compared with brook trout and Alsatian charr. Moreover, the results indicated differences in infection susceptibility, not only among different salmonid species but also among different lineages of charr and rainbow trout. Our study indicated that some salmonid species and even different lineages of the same species are more suitable for farming under PKD pressure.

Morphological and molecular description of Armillifer moniliformis larvae isolated from Sri Lankan brown palm civet (Paradoxurus montanus).

We report Armillifer moniliformis species infecting the endemic Sri Lankan brown palm civet (Paradoxurus montanus) from the Knuckles Range Forest Conservation Area, Sri Lanka. Larval stages of A. moniliformis were found during the postmortem of three civet cats found dead. Morphological studies were done by a light microscope and a scanning electron microscope (SEM). Histopathological examination was conducted using tissue samples obtained from the liver. For the molecular analysis, DNA was extracted from the isolated third-stage larvae. The NADH dehydrogenase subunit 5 (ND5) and the second internal transcribed spacer region (ITS-2), a portion of the large subunit nuclear ribosomal DNA (28S), a portion of 18S ribosomal rRNA gene (18S), and cytochrome c oxidase subunit 1 gene (COX1) were amplified using polymerase chain reaction (PCR). Excysted third-stage larvae were observed in the lungs, omentum, the pleural cavity, the abdominal cavity, and the surface of the spleen and the pericardium. Around 88 third-stage larvae were isolated from three civet cats. First-stage larvae in the liver were surrounded by outer fibrous layer over the inner germinal layer and filled with clear fluid. Slight hemorrhage, leukocyte infiltration, and mild hepatocellular degeneration in the liver were observed. The SEM examination indicated the unique oral apparatus comprises the oval-shaped mouth opening in between two pairs of curved, retractile hamuli. The sequences obtained for ND5, ITS-2, 28S, 18S, and COX1 were 301, 382, 325, 414, and 644 bp in length respectively. Morphology, sequence similarity search, sequence alignment, and phylogenetic analysis identified this parasite as A. moniliformis.

DISEASE AND PATHOLOGICAL CONDITIONS OF AN ENDANGERED RODENT, MICROTUS CALIFORNICUS SCIRPENSIS, IN A CAPTIVE-REARING FACILITY AND IN THE WILD.

Causes of morbidity and mortality and a survey of infectious disease agents were collated from wild and colony-raised endangered Amargosa voles (Microtus californicus scirpensis). Six voles from the wild and 295 voles in the captive-breeding colony were included in the study upon identification of an infectious agent during screening, identification of clinical signs of disease, or finding a pathological condition or infectious agent on necropsy. Findings included 28 significant or incidental pathological conditions of seven organ systems and 19 parasitic, viral, bacterial, or fungal agents. Several voles captured in the wild had fungal osteomyelitis of the tail that disseminated systemically in a vole brought from the wild to the colony and may have been caused by a Penicillium sp. Three voles reintroduced from the colony to the wild experienced inanition and subsequent severe hepatic and moderate renal tubular lipidosis. The most common significant pathological conditions in colony-reared voles were chronic interstitial nephritis with proteinosis; cardiomyopathy; trichobezoars that, in intestines or cecocolic junctions, sometimes induced local rupture or infarction with peritonitis; multifocal gastrointestinal ulceration and colibacillosis; acute renal tubular necrosis or nephritis; sepsis; hepatic and renal lipidosis; molar apical elongation sometimes progressing to invasion of the calvarium; and mammary tumors. Uncommon diagnoses included intervertebral disc disease; microvascular dysplasia; and multifocal bacterial abscessation. Common or clinically important infectious agents included Demodex sp. mites in hair follicles, Demodex sp. in esophageal mucosa, and an outbreak of tropical rat mites thought to have been introduced via the straw bedding; gastrointestinal Helicobacter sp.; attaching and effacing Escherichia coli; and Citrobacter braakii, a possible zoonotic bacterium. This survey of species-specific diseases and pathogens was possible because the established health surveillance program that is part of the species recovery plan allowed for monitoring of voles throughout the duration of their natural life spans in captivity.

Skin nodules associated with parasitism with Henneguya sp. (Cnidaria: Myxosporea) in the neotropical fish Cyphocharax modestus.

A new myxozoan species, Henneguya sp., is described based on material from skin of Cyphocharax modestus. Mature myxospores are were elongate and ellipsoidal, measuring 21.4 ±â€¯1.2 (19.4-23.2) µm in total length, 5.1 ±â€¯0.3 (4.5-5.8) µm in width, 11.9 ±â€¯0.5 (10.9-12.7) µm in body length and 9.6 ±â€¯0.7 (8.4-10.5) µm in length of the caudal process. The polar capsules were elongated and had unequal sizes, with length of 5.1 ±â€¯0.4 (4.5-6.0) µm and 5.6 ±â€¯0.4 (4.9-6.3) µm for smaller and larger respectively and width of 1.8 ±â€¯0.2 (1.4-2.0) µm. The larger polar capsule had 8 turns in polar filament while the smaller polar capsule had 5 turns in polar filament. The macroscopic analysis revealed the presence of large nodules, which were located before and after the dorsal fin of the hosts. The histopathological analysis showed the development of nodules filled with plasmodia, surrounded by loose connective tissue, developed in the dermis of the skin. Many cysts containing countless spores, as well as free spores, were located in the dermis and hypodermis of the hosts, causing the disorganization of the connective tissue that is responsible for the support. This is the first record of a Henneguya species in C. modestus.

A morphological, molecular, and histopathological redescription of Henneguya nyongensis Fomena & Bouix, 1996 (Cnidaria: Myxobolidae) infecting the gills of Peter's elephantnose fish, Gnathonemus petersii (Günther) (Osteoglossiformes: Mormyridae), imported from Nigeria.

A Henneguya sp., morphologically resembling Henneguya nyongensis Fomena & Bouix, 1996, was isolated from the gills of Peter's elephantnose fish, Gnathonemus petersii Günther, imported from Nigeria. Plasmodia were located between lamellae and within the gill epithelium, often leading to lamellar fusion. Although slightly smaller, the myxospores from these fish were morphologically consistent with H. nyongensis. In valvular view, spores are elongate, pyriform with a rounded posterior and tapering caudal processes. Myxospore bodies are 9.6-12.3 (mean 11.2) µm long and 4.0-4.7 (mean 4.3) µm wide. Polar capsules are pyriform, elongate, 4.5-5.2 (4.7) µm long and 1.3-1.6 (1.4) µm wide, with a characteristic neck-like structure at the apical end. Sequence generated for the 18S small subunit rRNA gene did not directly match any sequences available on GenBank, but demonstrated 91% nucleotide similarity to an unpublished Henneguya sp. infecting Mormyrus kannume Forsskål. Herein, the description of H. nyongensis is supplemented with new data on histopathology, molecular characterisation, and expanded host and geographical range.

Pathology and Plasma Biochemistry of Common Eider (Somateria mollissima) Males Wintering in the Danish Part of the Western Baltic.

Blood biochemistry, body mass, and gross pathology of male eiders (Somateria mollissima) wintering in the Inner Danish Waters of the western Baltic Sea (the Great Belt Strait) were assessed in this study. In November 2015, 14 specimens were obtained from the area defined for examination. Of the subject animals captured, 1 had dilated intestines and 2 had granulomas with encapsulated shotgun pellets considered to be chronic in nature. All 14 males were determined to have enteritis along with acanthocephalan and trematode endoparasites. Compared with reference values for captive eiders, plasma values of alanine aminotransferase (93%), total bilirubin (45%), gamma-glutamyl transferase (41%), and alkaline phosphatase (92%) showed significant increases in all 14 male birds. Altogether, the plasma biochemistry and gross pathology findings suggest that up to as many as 20% of the eider males in the Inner Danish Waters of the western Baltic Sea may suffer from liver and bile duct lesions and enteritis. The overall effect on the bird's survival from the results of this investigation is unknown. Therefore, the authors emphasize that more research is required on wintering eiders in the western Baltic to obtain a better understanding of their overall health status during winter, as well as their responses to wound-related lesions associated with gunshot pellets.

Myxobolus okamurae sp. nov. (Myxosporea: Myxozoa) causing severe gill myxoboliosis in the cyprinid Labeo bata in a cold water wetland, Punjab (India).

During the present study on myxozoan parasites infecting gills of cyprinid carps inhabiting Ranjit Sagar Wetland, a new parasite, Myxobolus okamurae sp. nov. infecting gills of Labeo bata has been described based on morphology, histopathology and partial 18S rDNA sequencing. For M. okamurae sp. nov., hundred fish specimens were examined, out of which thirty-three had large cylindrical to round, white plasmodia in gills, each plasmodium measured 0.9-3.0 mm in diameter. The myxospore body was pyriform in shape, measuring 12.25 × 4.93 µm, with a small intercapsular process at the anterior end. The polar capsules were equal and pyriform in shape, measuring 6.06 × 1.45 µm having polar filaments forming coils up to 13-14 in number. The intensity of infection was recorded to be heavy as indicated by gill plasmodium index (GPI = 3). Sequence analysis showed that M. okamurae sp. nov. is 91% similar with M. catlae infecting gills of Catla catla from India followed by M. intimus infecting gills of Leuciscus idus from Hungary. The phylogenetic tree based on the final edited alignment (403 bp) with Maximum-Likelihood showed the high bootstrap value of 75 and formed two major clades involving M. okamurae sp. nov. with M. pendula M. catlae and M. dispar in one clade with a low bootstrap value of 23 and the rest of the species in a separate clade. The plasmodium was located in the gill lamella and typed as "intralamellar vascular type, LV3".

Continental-extent patterns in amphibian malformations linked to parasites, chemical contaminants, and their interactions.

Widespread observations of malformed amphibians across North America have generated both concern and controversy. Debates over the causes of such malformations-which can affect >50% of animals in a population-have continued, likely due to involvement of multiple causal factors. Here, we used a 13-year dataset encompassing 53,880 frogs and toads from 422 wetlands and 42 states in the conterminous USA to test hypotheses relating abnormalities and four categories of potential drivers: (i) chemical contaminants, (ii) land use practices, (iii) parasite infection, and (iv) targeted interactions between parasites and pesticides. Using a hierarchically nested, competing-model approach, we further examined how these associations varied spatially among geographic regions. Although malformations were rare overall (average = 1.6%), we identified 96 hotspot sites with 5%-25% abnormal individuals. Using the full dataset of 934 collections (without data on parasite infection), malformation frequency was best predicted by the presence of oil and gas wells within the watershed. Among collections also examined for parasite infection (n = 154), average parasite load and its interaction with pesticide application positively predicted malformations: wetlands with a greater abundance of the trematode Ribeiroia ondatrae were more likely to have malformed amphibians, but these effects were strongest when pesticide application was also high, consistent with prior experimental research. Importantly, however, the influence of these factors also varied regionally, helping explain divergent results from previous studies at local scales; parasite infection was more influential in the West and Northeast, whereas pesticide application and oil/gas wells correlated with abnormalities in the Northeast, Southeast, and western regions of the USA. These results, based on the largest systematic sampling of amphibian malformations, suggest that increased observations of abnormal amphibians are associated with both parasite infection and chemical contaminants, but that their relative importance and interaction strength varied with the spatial extent of the analysis.

Histopathology and external examination of heavily parasitized Lost River Sucker Deltistes luxatus (Cope 1879) and Shortnose Sucker Chasmistes brevirostris (Cope 1879) from Upper Klamath Lake, Oregon.

Shortnose Sucker (Chasimistes brevirostris) and Lost River Sucker (Deltistes luxatus) are endemic to the Upper Klamath Basin of Southern Oregon and Northern California, and their populations are in decline. We used histopathology and external examination of 140 and external examination only of 310 underyearling suckers collected in 2013, 2015 and 2016 to document pathological changes, particularly those relating to parasites. The most severe infection was caused by a Contracaecum sp., infecting the atrium of 8%-33% of Shortnose Suckers. The most prevalent infections were caused by Bolbophorus sp. metacercariae in the muscle of Shortnose Suckers (21%-63%) and Lernaea cyprinacea in the skin and muscle of Lost River Suckers (30%-81%). Histology detected Bolbophorus in only 5% of cases where it was not seen externally. Three myxozoans were observed; a Parvicapsula sp. in the renal tubules (10%), a Myxobolus sp. in the intestinal mucosa (2%) and an unusual multicellular, presporogonic myxozoan in the intestinal lumen of one sucker. Severe gill epithelial hyperplasia was observed in several fish collected in 2016. Trichodinids and Ichthyobodo sp. were observed on some of the gills, but absent in many of the fish with severe lesions. A histiocytic sarcoma was observed in sucker.

Histopathological and ultrastructural assessment of two mugilid species infected with myxozoans and helminths.

The histopathology and ultrastructure of the intestine of mullets, Liza ramada and Liza saliens, from Comacchio lagoons (northern Italy) naturally infected with myxozoans and helminths were investigated and described. Sixty-two (80.5%) of 77 mullets harboured one or more of the following parasites species: Myxobolus mugchelo (Myxozoa), Neoechinorhynchus agilis (Acanthocephala), Haplosplanchnus pachysomus and Dicrogaster contractus (Digenea). Co-occurrence of helminths with myxozoans was common. The main damage caused by digeneans was destruction of the mucosal epithelium of the villi, necrosis and degeneration of intestinal epithelial cells. More severe intestinal damage was caused by acanthocephalans which reach the submucosa layer with their proboscis. At the site of helminths infection, several mast cells (MCs), rodlet cells (RCs), mucous cells and few neutrophils and macrophages were observed in the epithelium. RCs and mucous cells exhibited discharge activity in close vicinity to the worm's tegument. M. mugchelo conspicuous plasmodia were encysted mainly in muscle and submucosa layers of the intestine. Indeed, spores of M. mugchelo were documented within the epithelial cells of host intestine and in proximity to MCs. Degranulation of the MCs near the myxozoans was very frequent.

Natural selection on individual variation in tolerance of gastrointestinal nematode infection.

Hosts may mitigate the impact of parasites by two broad strategies: resistance, which limits parasite burden, and tolerance, which limits the fitness or health cost of increasing parasite burden. The degree and causes of variation in both resistance and tolerance are expected to influence host-parasite evolutionary and epidemiological dynamics and inform disease management, yet very little empirical work has addressed tolerance in wild vertebrates. Here, we applied random regression models to longitudinal data from an unmanaged population of Soay sheep to estimate individual tolerance, defined as the rate of decline in body weight with increasing burden of highly prevalent gastrointestinal nematode parasites. On average, individuals lost weight as parasite burden increased, but whereas some lost weight slowly as burden increased (exhibiting high tolerance), other individuals lost weight significantly more rapidly (exhibiting low tolerance). We then investigated associations between tolerance and fitness using selection gradients that accounted for selection on correlated traits, including body weight. We found evidence for positive phenotypic selection on tolerance: on average, individuals who lost weight more slowly with increasing parasite burden had higher lifetime breeding success. This variation did not have an additive genetic basis. These results reveal that selection on tolerance operates under natural conditions. They also support theoretical predictions for the erosion of additive genetic variance of traits under strong directional selection and fixation of genes conferring tolerance. Our findings provide the first evidence of selection on individual tolerance of infection in animals and suggest practical applications in animal and human disease management in the face of highly prevalent parasites.

Locally extensive meningoencephalitis caused by Miamiensis avidus (syn. Philasterides dicentrarchi) in a zebra shark.

Scuticociliatosis, caused by ciliated protozoa in the subclass Scuticociliatia of the phylum Ciliophora, can cause fatal disease in teleost fish species. However, information on scuticociliatosis in elasmobranchs is still scarce. In this report, we describe a case of locally extensive meningoencephalitis caused by Miamiensis avidus (syn. Philasterides dicentrarchi) in a 2 yr old captive zebra shark Stegostoma fasciatum. Granulocytic meningoencephalitis was observed through histological assessment. Inflammation was confined to the ventral aspect of the brain with a large number of ciliated protozoa, transforming into non-suppurative meningitis in the lateral aspect, and gradually vanished in the dorsal aspect. No histopathological and polymerase chain reaction (PCR) evidence of systemic dissemination of M. avidus was found. PCR targeting the gene coding the small-subunit ribosomal RNA (SSUrRNA) of M. avidus was performed on the brain, liver, and gill tissues, and only brain tissue yielded a positive result. The DNA sequences from amplicons of the protozoal SSUrRNA gene were completely matched to that of M. avidus. The distribution of protozoa in the current case was mainly located in the brain and suggests the possibility of a direct neural invasive pathway of M. avidus through the nasal cavity/ampullary system and/or a unique tissue tropism of M. avidus specific to the brain in zebra sharks. Further investigations on the pathogenesis of M. avidus in elasmobranchs, especially zebra sharks, are needed.

Quantifying parasite presence in relation to biological parameters of harbour porpoises Phocoena phocoena stranded on the Dutch coast.

Harbour porpoises are often found to be infected by endoparasites in several organs including the lungs and stomach as well as the heart, liver and ears. Nevertheless there is still little knowledge about the impact, ecology, transmission, and virulence of these parasitic infections. Here, we profile the presence of parasites in 4 frequently infected organs (lungs, stomach, liver and ears) in relation to biological parameters of harbour porpoises stranded along the Dutch coastline between December 2008 and December 2013. We found that parasites were common, with prevalence of 68% in lungs, 74.4% in ears, 26% in stomach and 23.5% in liver. We used generalised linear models to further quantify parasite presence in relation to biological data gathered during necropsy (sex, body length and nutritive condition). Body length (used as a proxy for age) was significant in explaining parasite presence for all organs with increasing probability of having the parasite with increasing body length. For the parasitic infections in the ears and stomach the nutritive condition was an additional significant factor, with a higher probability of parasite presence in porpoises in a poorer nutritive condition. The results of this study can be used as a baseline for assessing parasite presence in harbour porpoises and are a first step towards linking parasite infections to basic biological data gathered during necropsy.

Comparative study of proliferative kidney disease in grayling Thymallus thymallus and brown trout Salmo trutta fario: an exposure experiment.

Proliferative kidney disease (PKD) is an emerging disease threatening wild salmonid populations, with the myxozoan parasite Tetracapsuloides bryosalmonae as the causative agent. Species differences in parasite susceptibility and disease-induced mortality seem to exist. The aim of the present study was to compare incidence, pathology and mortality of PKD in grayling Thymallus thymallus and brown trout Salmo trutta under identical semi-natural conditions. Young-of-the-year grayling and brown trout, free of T. bryosalmonae, were jointly exposed in cage compartments in a river in the northeast of Switzerland during 3 summer months. Wild brown trout were caught by electrofishing near the cage, and PKD status was compared with that of caged animals. Cage-exposed grayling showed a PKD incidence of 1%, regardless of whether parasite infection was determined by means of real-time PCR or histopathology/immunohistochemistry. In contrast, PKD incidence of caged brown trout was 77%. This value was not significantly different to PKD prevalence of wild brown trout caught above and below the cage (60 and 91%, respectively). Mortality in grayling was significantly higher compared with that of brown trout (40 versus 23%); however, grayling mortality was not considered to be associated with PKD. Mortality of caged and infected brown trout was significantly higher than mortality of non-infected caged trout. Histopathology indicated an ongoing mostly acute or chronic active infection in brown trout, which survived until the end of exposure. The results suggest that grayling are less susceptible to infection with T. bryosalmonae compared with brown trout under the tested field conditions.

Myxobolus sp. and Henneguya sp. (Cnidaria: Myxobolidae) natural co-infection in the kidney of Piaractus mesopotamicus (Characiformes: Serrasalmidae).

This study evaluated the myxozoan infection and histopathology of the kidney of freshwater fish Piaractus mesopotamicus from intensive fish farming in Brazil. A total of 55 fish were examined for myxozoan infection. Infected organs were processed by usual histology and stained with hematoxylin-eosin (H&E) and Ziehl-Neelsen (ZN). From the total of 55 fish analyzed, 47 (85.45%) presented myxospores, being 9.09% (5/55) only with Myxobolus sp., 5.45% (3/55) only with Henneguya sp., and 70.91% (39/55) presenting both parasites. The presence of myxospores was associated with histological alterations in both stromal and renal parenchyma. Myxospores were found mostly in the peritubular interstitial tissue and in low intensity in the glomerulus which caused nuclear hypertrophy and loss of Bowman space. An increase in the glomerular tuft and a reduction in the lumen of the collector tubules were also observed, besides the high number of melanomacrophage cells in the glomerulus. This study reports for the first time detection of myxozoan mixed infection in one organ of pacu and discuss the possible transportation of myxospores in the circulating blood.

DECLINE OF GAME BIRDS (PHASIANUS COLCHICUS AND PERDIX PERDIX) IN BAVARIA: A SURVEY ON PATHOGENIC BACTERIA, PARASITES, PESTICIDE RESIDUES, AND INFLUENCE OF SET-ASIDE LAND AND MAIZE CULTIVATION.

Due to a Europe-wide decline of grey partridge ( Perdix perdix ) and pheasant ( Phasianus colchicus ) populations, this study was conducted focusing on the county of Bavaria, south Germany. The aim was to assess the health status of game birds and identify possible causes of decline. For this purpose 203 pheasants and 11 partridges were examined during the 2011 hunting season. Pathologic examinations were conducted including examinations for parasites and bacteria. Due to public health significance, a screening for Salmonella sp., as well as real-time polymerase chain reaction examinations for Campylobacter sp. and Mycobacterium avium ssp. avium, were done. Because pesticides and land-usage can possibly influence bird numbers, the birds were screened for environmental toxin residues, including neonicotinoid insecticides, and land-usage data were correlated with the hunting bags. The result was a very-strong positive correlation of set-aside areas and a less-strong negative correlation of maize cultivation acreage. More than 90% of the birds had a good health status; only individuals showed pathologic alterations. For example, avian tuberculosis was found in two pheasants and a severe capillariosis in two partridges. A possible role of female reproductive disorders has to be confirmed in further investigations. In conclusion, results suggest the decrease of set-aside areas could be a possible reason for decline.

A structural colour ornament correlates positively with parasite load and body condition in an insular lizard species.

Pigment-based ornaments in vertebrates may reflect the body condition or health status of the individual in correlation with environmental stress and hormonal balance. Among the environmental factors shaping sexual colouration, parasitic infections have been stressed as an important evolutionary pressure constraining the maintenance of pigment-based ornaments. However, the honesty of structure-based ornaments in vertebrates is still under debate. Structural UV-biased ornaments in Gallotia lizards were described as a trait used by conspecifics during mate and rival assessment suggesting the reliability of these signals. We investigated the relationship between parasitaemia, body condition and a structural-based ornament present in the cheek of the sexually dichromatic Canarian lacertid Gallotia galloti in a population with an almost 100 % prevalence of haemoparasites. Using spectrophotometric techniques, we found that males with higher values of cheek UV chroma were infected with more haemoparasites. No significant relationship was found between haemoparasite load and body condition. However, males with higher cheek UV chroma showed significantly better body condition. In addition, we found that cheek hue was significantly related to body condition of individuals in both sexes. In males, cheek reflectivity biased towards the UV range was significantly related to better body condition. In females, those individuals with better body condition showed more whitish cheeks with less UV suggesting that cheek hue serves as an intersexual signal for sex recognition. We conclude that the positive relationship between cheek chroma and parasite load in male lizards is compatible with both differential density of melanin and iridophore arrangement in the dermis conveying an individual's ability to cope with environmental stress.

Cutaneous myxidiosis in European eel, Anguilla anguilla (Linnaeus, 1758): histopathology, histochemistry and laminin immunohistochemistry.

Histopathology, histochemistry and immunohistochemistry of the integument of European eel, Anguilla anguilla (Linnaeus, 1758), infected by Myxidium sp. are reported. Skin samples from affected and unaffected eels were dissected, formalin fixed, paraffin embedded, sectioned and stained with H&E, Periodic acid-Schiff's staining method, Alcian Blue 8 GX pH 2.5/Periodic acid-Schiff's and McCallum-Goodpasture's Gram stain. Moreover, immunohistochemistry was performed using a primary polyclonal laminin antibody. Histologically, cysts (diameter 2-3 mm) were observed mainly under the scale pockets, encircled by a thin collagen layer, lined by elongated, flattened fibroblasts and containing bipolar, PAS- and Gram-positive spores with opposite polar capsules. The epidermis stretched by the underlying cyst appeared dysplastic, thinned with a significant reduction in mucous cells number. Only inconsistent and aspecific inflammatory reaction was noted around the cysts at the dermis/epidermis interface. Intense laminin-like protein immunolabel was documented in the plasmodial ectoplasm and related to host anergia. This was the first report of laminin immunolabel in a member of the Myxozoa. Epidermal dysplasia represents likely an aspecific response against the underlying tensile force exerted by the developing parasite cyst, while fibroblast and collagen encapsulation denote a parasite-driven host response protecting, rather than harming, the encircled parasite.