Distribution Of Parasites Research Articles

Two new species of kidney fluke (Trematoda: Renicolidae) from New Zealand penguins (Spheniscidae), with a description of Renicola websteraen. sp.

This study describes Renicola websterae n. sp., a newly identified kidney fluke (Renicolidae: Trematoda) infecting two penguin species from New Zealand, the little blue penguin (Eudyptula novaehollandiae) and the Fiordland crested penguin (Eudyptes pachyrhynchus). Morphological and molecular analyses, including phylogenies based on cox1 and 28S genes, confirmed the distinctiveness of R. websterae. Key morphological features were discerned to be statistically comparable across five developmental stages, facilitating detailed characterization even in less mature specimens. A putative second, genetically distinct Renicola sp. was identified in Fiordland crested penguins and intermediate fish hosts, indicating a potential trophic link, and partly completing the known life cycle. We discuss the fact that kidney flukes have only been found in these two penguins and not in other New Zealand species, and the ecological and host-specificity factors likely influencing parasite distribution. This work represents the first record of a named Renicola species from New Zealand and only the second species found in penguins worldwide.

Dynamics of Reinfection by Neobenedenia sp. (Monogenea, Capsalidae) in Almaco Jack, Seriola rivoliana, Kept in a Cultivation System.

Fish susceptibility to parasitic infection is a crucial issue in aquaculture, where the density of captive fish increases the intensity of parasitic infections. Monogeneans are a group of parasitic flatworms that include pathogenic species for fish, among them Neobenedenia spp., which pose significant challenges for fish health in farming systems. Understanding the dynamics of parasitism in fish and how they may vary according to host susceptibility or environmental conditions is essential for the development of effective management strategies in aquaculture. Therefore, the aim of this study was to investigate the individual susceptibility of Almaco jack (Seriola rivoliana) to infections by Neobenedenia sp. and examine how reinfection affects parasite load in an aquaculture setting. Our findings unveiled an aggregated distribution of parasites in the fish population, indicating a non-random pattern influenced by specific host factors. Furthermore, our results revealed that even minor temperature variations, such as an increase of just 1°C, were associated with a noticeable rise in parasite abundance. These results underscore the importance of regular monitoring in S. rivoliana tank-maintained systems, as even minor temperature fluctuations can cause a substantial increase in Neobenedenia sp. infections, particularly in more susceptible individuals.

Impact of the intensity of infection in birds on Plasmodium development within Culex pipiens mosquitoes

BackgroundIn vector-borne diseases, invertebrate hosts are exposed to highly variable quantities of parasites during their blood meal. This heterogeneity may partly explain the overdispersed distribution of parasites within the vector population and the variability in the extrinsic incubation period (EIP) of the parasite. Indeed, the quantity of parasites ingested is often considered as a good predictor of the quantity of parasites that will develop within the vectors, as well as the speed at which they will develop (i.e. EIP). However, density-dependent processes can influence the relationship between parasite burden in the vertebrate host and in vectors, making this relationship unclear at times.MethodsHere, we used an avian malaria system to investigate whether the proportion of red blood cells infected by sexual and/or asexual stages of Plasmodium relictum influences the intensity of infection and the EIP within vectors. For this purpose, we experimentally infected 12 birds in order to generate a range of infection intensity. More than 1000 mosquitoes took a blood meal on these hosts, and the development of Plasmodium within the vectors was followed for more than 20 days.ResultsOur study reveals a negative relationship between the intensity of infection in birds and the time until 10% of mosquitoes become infectious (EIP10). A period of only 4 days was sufficient to detect sporozoites in at least 10% of mosquitoes fed on the most infected hosts. However, the number of sporozoites did not vary significantly according to the vertebrate host intensity of infection, but was positively correlated to the oocyst burden (parasitic stage preceding the sporozoite stage).ConclusionsWhile the quantity of ingested parasites had no impact on oocyst and sporozoite burden in infectious mosquitoes, the EIP10 was affected. Studies have demonstrated that small changes in the EIP can have a significant effect on the number of mosquitoes living long enough to transmit parasites. Here, we observed a difference of 4–6 days in the detection of the first sporozoites, depending on the intensity of infection of the bitten vertebrate host. Considering that a gonotrophic cycle lasts 3–4 days, the shortened EIP may have significant effects on Plasmodium transmission.Graphical

Comparison of Parasite Prevalence in Marine Fish Sardinella maderensis (Teleostei: Clupeidae) According to Different Length and Fish Sex in the Waters Near the Coast of Benin, West Africa

Aims: This study was designed to assess the diversity and the occurrence of parasites in Sardinella maderensis and the relationship between the prevalence of infestation and the fish length and sex. Place and Duration of Study: Fish samplings were realized in the Artisanal fishing port of Cotonou between November 2019 and March 2020. Methodology: During the study, 101 males and 64 females were sampled. They were kept on ice and transported into the laboratory. Each specimen was labeled and the length was mesure. Then, they were dissected to get the internal organs for endoparasites examination. After parasite identification and counting, the prevalence, mean abundance, and mean intensity were assessed. Ecological indices for parasite community analysis such as Shannon Wiener index, Piélou equitability index, and Jaccard’s Similarity index were determined. The chi-square test was performed to appreciate the probable significant variation between sex prevalence and length classes. Results: A total of 742 individuals and eleven (11) species of the harvested parasites were distributed in five groups such as Monogenea, Digenea, Cestoda, Nematoda, and Copepoda. Nematoda were mostly represented in terms of number of recorded species and mean abundance. Total prevalence was 92.12%. No significant difference was recorded between prevalence in males and females (chi2 = 1.168; P = 0.279) on one hand and prevalence in fish length (chi2 = 2.41 ; P = 0.66). Cestoda exhibited a high prevalence while the high mean abundance was encounterd for nematoda. Nematoda has encountered 4 species whereas the two Trematoda were represented by only one species, each one. Ecological index record were representative of the equilibrium in parasite distribution between hosts sex. Conclusion: Parasitism in S. maderensis was characterized by an important fauna of parasites mainly represented by Nematoda and Digenea. The prevalence of parasites was not related to the host’s length or sex. These results, however, need further work to validate reliability.

Fight Not Flight: Parasites Drive the Bacterial Evolution of Resistance, Not Escape.

AbstractIn the face of ubiquitous threats from parasites, hosts can evolve strategies to resist infection or to altogether avoid parasitism, for instance by avoiding behavior that could expose them to parasites or by dispersing away from local parasite threats. At the microbial scale, bacteria frequently encounter viral parasites, bacteriophages. While bacteria are known to utilize a number of strategies to resist infection by phages and can have the capacity to avoid moving toward phage-infected cells, it is unknown whether bacteria can evolve dispersal to escape from phages. To answer this question, we combined experimental evolution and mathematical modeling. Experimental evolution of the bacterium Pseudomonas fluorescens in environments with differing spatial distributions of the phage Phi2 revealed that the host bacteria evolved resistance depending on parasite distribution but did not evolve dispersal to escape parasite infection. Simulations using parameterized mathematical models of bacterial growth and swimming motility showed that this is a general finding: while increased dispersal is adaptive in the absence of parasites, in the presence of parasites that fitness benefit disappears and resistance becomes adaptive, regardless of the spatial distribution of parasites. Together, these experiments suggest that parasites should rarely, if ever, drive the evolution of bacterial escape via dispersal.

Pre‐ and postinfection priority effects have contrasting outcomes for parasite prevalence in host populations

AbstractParasite species frequently co‐occur more or less than expected by chance. These nonrandom co‐occurrence patterns can be driven by pre‐ or postinfection priority effects: parasites are more or less likely to attempt infection in a host already infected by another parasite species or may have higher or lower establishment and survival in hosts already infected by another parasite species. How these two types of priority effects differentially affect parasite distributions at the host population level remains unexplored. Using a probabilistic state transition diagram parameterized with field data and analyzed with two simulation methods, I show that the two types of priority effects lead to contrasting outcomes at the host population level. As preinfection priority effects transition from facilitation to inhibition, uninfected hosts decrease by up to 39%, and hosts infected by both parasites decrease by up to 84%, with concomitant increases in single infections by either parasite species. In contrast, as postinfection priority effects transition from facilitation to inhibition, the proportion of uninfected hosts remains unchanged, but the proportion of hosts infected by both parasites decreases by up to 89%, with increases in hosts singly infected by the first‐arriving parasite. Interactions between parasites at the within‐host level and the specific nature of those interactions alter infection patterns at the host population level.

Metazoan parasites associated with marine mollusks inhabiting the China Seas: a review

Parasites in mollusks are often neglected by humans, while some species were reported to be harmful to economic mollusks and caused production decrease. Metazoan parasites of mollusk studies from the China Seas started relatively later than other countries. To promote long-term studies on the distribution and diversity of metazoan parasites of mollusks from the China Seas, a comprehensive review has been carried out based on the available literature. The purpose of this study was to perform a critical review about the metazoan parasites associated with mollusks that are useful for the discovery of new metazoans. This publication summarizes information on metazoan parasites of Chinese mollusks from 1932 to 2024. The information is presented and contains 128 species of parasites, distributed among the higher taxa as follows: Turbellaria (2 species), Trematoda (34 species), Cestoda (1 species), Annelida (38 species), Arthropoda (48 species), Porifera (2 species), Cnidaria (1 species), and Mollusca (2 species). Many records of parasites not identified to the species level are also included. Collectively, this review provides a synopsis of the known metazoan parasites of mollusks from the China Seas, as well as presents the known relationship between metazoan parasites and the mollusks, which will broaden our knowledge on the metazoan parasites of mollusks. It is important as it highlights the lack of metazoan parasite studies done in the China Seas and the need for more parasite biodiversity work.

Frequency and Distribution of Parasites Detected in Children Between 2017-2022 (6-year Period).

In the study, various complaints such as gastrointestinal complaints such as diarrhea, constipation, abdominal pain, nausea and vomiting, weight loss, night urination, itching around the anus, malnutrition, malabsorption, anemia, intelligence and developmental delay were reported to University of Health Sciences Türkiye, Dr. Behçet Uz Pediatric Diseases and Surgery Training and Researhc Hospital, Microbiology Laboratory between 2017 and 2022. It was aimed to determine the frequency and distribution of intestinal parasites in patients presenting with clinical symptoms. In the study, the results of 33,249 stool and 3499 cellophane tape samples sent to the microbiology laboratory between January 2017 and September 2022 were evaluated. The stool samples were examined with saline-Lugol, modified Kinyoun acidfast and trichrome staining methods. Parasites were detected in the stool samples of 1.8% of a total of 36,748 patients. The intestinal parasite detected at the highest rate was Entamoeba histolytica (67%). In order of frequency: Enterobius vermicularis (19%), Giardia intestinalis (12%), Ascaris lumbricoides (0.6%), Hymenolepis nana (0.2%) Blastocystis spp. (0.2%) is followed by Hymenolepis diminuta (0.2%). While the rate of parasite occurrence in patients applying was found to be 19.9% in 2017, 24.6% in 2018, and 28.6% in 2019, this rate decreased to 4.3% in 2020, 16% in 2021 and 6.6% in 2022. Looking at the distribution of parasites by years, it is seen that there was a decrease in the rate of parasite occurrence with the start of the Coronavirus disease-2019 pandemic in 2020. We believe that infection control measures and strict enforcement of quarantine rules to reduce the spread of severe acute respiratory syndrome-coronavirus-2 may have significantly reduced the parasite positivity rate during the pandemic period. Data on intestinal parasites in Türkiye show regional differences, and national surveillance studies are needed, especially in children.

Australian guidelines for equine internal parasite management.

Over the past few decades, the emergence of resistance amongst intestinal parasites of horses to all available anthelmintic classes has emphasised the need for a paradigm shift in parasite control approaches within the Australian equine industry. Findings of a recent Australia-wide research project have provided new insights into intestinal parasites (i.e. strongyles and ascarids) and parasite control from the perspectives of Australian horse breeders and equine veterinarians. The published data have revealed recent trends in parasite prevalence and distribution, breeders' and veterinarians' attitudes and perspectives on controlling horse internal parasites, the efficacy of commonly used anthelmintic products and post-treatment egg reappearance periods. These studies have formed the basis of newly developed guidelines managing and treating gastrointestinal nematodes in horses. Tailored for equine veterinarians, these guidelines contain information on target parasites and risk factors for their transmission, as well as practical advice for surveillance, anthelmintic choice, timing of treatment, testing for anthelmintic resistance and managing refugia. The Australian Guidelines for Equine Internal Parasite Management (AGEIPM) will serve as a pocket companion for equine veterinarians, providing best-practice recommendations grounded in locally conducted scientific research. Dissemination and extension of the AGEIPM to industry will strengthen the client-practitioner relationship. The aim is to reduce reliance on blanket deworming in equine parasite management programs and help curb the progression of resistance to the limited anthelmintic classes available for treating horses.

Potentially zoonotic parasite arrives to continental France: Clinostomum complanatum (Trematoda: Digenea) infection in perch (Perca fluviatilis) from the Doubs River (Jura).

Clinostomum complanatum (Rudolphi, 1814) is known as a food-borne zoonotic parasite using freshwater fish as intermediate host, although in its native distribution area in Europe, the Danube and Po basins and the northeast of Italy, no cases have been reported. This study reports a new geographic location outside the native distribution range of this parasite. We detected high infection levels of C. complanatum in wild perch (Perca fluviatilis Linnaeus) from the Doubs River in continental France. Clinostomum complanatum reached a prevalence of 97% and mean intensity of 5.8 cysts per fish in 33 fish examined, with most fish already infected by the age of two years. No correlations were observed between fish traits (standard length, weight, age and sex) and the number of parasites. The distribution of C. complanatum cysts in the fish body was not random. The tissue surrounding the opercula and branchial cavity, and muscles along the lateral line and near the pectoral, dorsal and caudal fins were the preferred sites of infection. Morphological identification was confirmed with molecular data. The French specimens shared identical mt cox1 haplotypes with specimens from Italy. The distribution of this exotic parasite in freshwaters in continental France deserves further research. Under the current French law, the parasite occurrence represents an economic loss for the local freshwater aquaculture industry, and a possible zoonotic risk for consumers if undetected, especially when raw or marinated fish is consumed. We provided a list of all reported hosts for C. complanatum from the western Palaearctic, discussed the knowledge gap regarding the zoonotic risk of C. complanatum in Europe, and highlighted the lack of policy that may increase the hazards posed by food-borne emerging parasites and their broader ecological impacts as alien species in freshwaters in Europe.

An epidemiological study of malaria parasites among long–tailed macaques (Macaca fascicularis), pig–tailed macaques (Macaca nemestrina) and silver–leaf monkeys (Trachypithecus cristatus) in Sumatra Region, Indonesia

Objective: To ascertain the prevalence and distribution of malaria parasites among the three monkeys species from three provinces in Sumatra Island, Indonesia. Methods: Infections with Plasmodium spp. were determined morphologically from the blood smears which were stained with Giemsa solution and molecularly through nested polymerase chain reaction (PCR) in DNA samples from 68 primates, which were captured at three locations: Jambi (Bungo district), Bengkulu (Muko-Muko district), and Riau Islands (Lingga district). Results: Out of 68 samples analyzed, 46 were positive for various Plasmodium species, including Plasmodium knowlesi, Plasmodium cynamolgi, Plasmodium inui, and Plasmodium coatneyi. Over one-third of the population exhibited multiple infections, with Plasmodium inui being the most predominant strain. Conclusions: The high prevalence of multiple malaria infections in monkeys, coupled with the rising reports of primate malaria cases in human raises questions about the potential for human transmission. These findings emphasize the necessity for ongoing monitoring and endeavors to comprehend and alleviate the risk of zoonotic malaria transmission, particularly in areas experiencing environmental changes.

GASTROINTESTINAL PARASITES AND ASSOCIATED GUT PATHOLOGY IN CHICKENS SOLD AT LIVE-BIRD MARKETS IN LAGOS STATE, SOUTHWESTERN NIGERIA

Gastrointestinal (GI) parasites compromise intestinal health in poultry, causing impaired nutrient uptake, poor growth rate and reduced productivity. The effectiveness of control programs relies on an accurate understanding of parasite occurrence and distribution. This survey aimed to determine the diversity and pathological effects of GI parasites of chickens in Lagos State, Nigeria. Three hundred and sixty-four (364) chickens were randomly sampled from selected live-bird markets. Standard parasitological methods were employed to process and examine gastrointestinal content and mucosal scrapings for parasite identification. Live helminths were preserved in 70% ethanol, cleared in lactic acid and identified at the species level. Sections of the gut were also assessed for microscopic lesions following standard histopathological procedures. Findings revealed that 251 (69%) of the 364 sampled chickens were infected with GI parasites. Eleven nematodes, 5 cestodes and coccidia of the genus Eimeria were detected. Ascaridia galli (140, 38.5%), Eimeria spp. (98, 26.9%) and Heterakis gallinarium (82, 22.5%) were the most common parasites found. Helminths were generally more prevalent in local and male chickens (P<0.05) whereas exotic breeds had higher infection rates for Eimeria spp. (P>0.05). Histopathological analyses revealed mild to severe inflammation, oedema, mucosal erosion, and hyperplasia in infected chickens. This study showed that GI parasites are prevalent in chickens and are associated with intestinal damage that can undermine poultry growth and productivity in the study area. Efforts to control must be strengthened to secure chicken production, maintain food security, and prevent economic losses.

Canine vector-borne parasites in the Galapagos

BackgroundThe extraordinary Galapagos Islands, with an impressive number of endemic and native species, maintain the interest and curiosity for researchers from all over the world. The native species are known to be vulnerable to new pathogens, cointroduced with their invasive hosts. In the case of invasive parasitic arthropods, their evolutionary success is related to the association with other invasive hosts (such as domestic animals). These associations could become a significant driver of change, as occasionally they can seek another hosts and have the capacity to transmit pathogens between domestic and wild animals. The current study aims to identify the distribution and abundance of canine vector-borne parasites in the Galapagos Islands based on the possibility that some of them could spill over to endemic mammals.MethodsA total of 1221 blood samples were randomly collected from privately owned dogs on San Cristóbal, Isabela, Santa Cruz, and Floreana Islands during the years 2021 and 2022. All samples were examined for vector-borne pathogens using the modified Knott’s test and conventional, nested, and multiplex polymerase chain reactions (PCRs), followed by sequencing.ResultsThe PCR and Knott tests confirmed the presence of Dirofilaria immitis (2%, 25/1221) in all islands. While molecular analyses showed heartworm DNA only in dogs from the San Cristóbal (3.3%) and Isabela (2.4%) Islands. Moreover, other pathogens Babesia vogeli (3%, 37/1221) and Hepatozoon canis (0.2%, 2/1221) were detected for the first time by molecular analyses.ConclusionsDogs from Galapagos are hosts to various pathogens, of which some are potentially zoonotic while some other could be spill-over to endemic endangered carnivores, such as sea lions. To understand and limit their impact, long-term surveillance, control, and awareness is needed.Graphical abstract

Occurrence of Toxoplasma gondii in cattle and sheep in Akmola and Kostanay regions of Kazakhstan.

Toxoplasma gondii is an intracellular protozoan and a major foodborne pathogen worldwide. Nearly, all warm-blooded animals are susceptible to toxoplasmosis, with raw and undercooked meat and animal products serving as the primary transmission routes. To date, the distribution of T. gondii among farm animals in Kazakhstan has been inadequately studied. This study aimed to determine the occurrence of antibodies against T. gondii in cattle and sheep in the Akmola and Kostanay regions. Blood samples were randomly collected from 437 cattle and 397 sheep from two regions of Kazakhstan: Akmola and Kostanay. A commercial enzyme-linked immunosorbent assay based on the native protein Toxoplasma surface antigen 1 was used for serological analysis. The occurrences of T. gondii were 8.0% and 3.8% among cattle and 42.1% and 19.0% among sheep in the Akmola and Kostanay regions, respectively. Antibodies against T. gondii were detected in all study areas. The greatest frequency of seropositive reactions in cattle was observed in the Arshaly region (9.0%), whereas the least frequent was observed in Arkalyk (3.3%). The highest occurrence of seropositive reactions among sheep was found in the Zerenda region (54.5%), whereas the lowest was found in the Auliekol region (15.6%). The obtained results confirmed the circulation of the T. gondii pathogen among cattle and sheep in the investigated regions. These findings provide insight into the current distribution of this zoonotic parasite among farm animals in Kazakhstan.

Expanding the known haemosporidian parasite diversity in Eurasian Bluethroat (Luscinia svecica) subspecies through amplicon sequencing

Expanding the known haemosporidian parasite diversity in Eurasian Bluethroat (Luscinia svecica) subspecies through amplicon sequencing

Prevalence of intestinal parasites and associated factors among patients with HIV/AIDS at the anti-retroviral treatment clinic of Mizan-Tepi University Teaching Hospital, Southwest Ethiopia.

Intestinal parasitic infections remain very common, particularly in areas with a high prevalence of immune-compromised patients, such as HIV/AIDS patients. The purpose of this study was to determine the prevalence of intestinal parasites and associated factors in people living with HIV/AIDS at an ART clinic in Mizan-Tepi University Teaching Hospital, southwest Ethiopia. A cross-sectional survey was conducted from July to September 2021. A total of 191 adult people living with HIV/AIDS participated in this study. Data on socio-demographic, clinical, and other risk factors were collected using a structured questionnaire. Stool samples were collected and processed using a direct wet mount, formol-ether concentration, and modified Ziehl-Nelson staining techniques. The data were analyzed using the Statistical Package for Social Sciences Version 25 software. Among 67 adult individuals living with HIV/AIDS, the prevalence of intestinal parasites was 35.1%. Specifically, 31.5% (45/143) of patients on antiretroviral therapy (ART) and 45.8% (22/48) of ART-naïve patients were infected. The distribution of intestinal parasites was as follows: protozoa were found in 14.7% of ART-treated patients and 22.9% of ART-naïve patients; helminths in 15.4% of ART-treated patients and 16.7% of ART-naïve patients; and opportunistic parasites in 1.4% of ART-treated patients and 6.25% of ART-naïve patients. Significant associations with a higher prevalence of intestinal parasites were observed for a CD4 count <200 cells/mm3 (Adjusted Odds Ratio [AOR] = 3.77; 95% Confidence Interval [CI]: 1.01-13.15; p = 0.04), consumption of unwashed raw vegetables (AOR = 3.29; 95% CI: 1.23-8.86; p = 0.02), and residing in rural areas (AOR = 2.34; 95% CI: 1.27-4.32; p = 0.01). The findings indicate that a significant proportion of adults living with HIV/AIDS are affected by intestinal parasites, with a notably higher prevalence among ART-naïve patients compared to those on ART. Factors such as a low CD4 count, consumption of unwashed raw vegetables, and rural residence are associated with increased risk of intestinal parasite infections. These results underscore the importance of improving hygiene practices and access to healthcare, particularly in rural areas, to reduce the burden of parasitic infections among individuals living with HIV/AIDS.

Examination of Prevalence and Sex-Related Variation in Gill and Gastrointestinal Tract Parasite Infestation of Clarias Species in ‘Tella’ Area of River Taraba, Nigeria

The presence of certain parasites in Clarias species consumed in Nigeria has continued to pose some challenges to fish production in many parts of Nigeria. The present study was aimed at assessing the sex-related distribution of parasites in gills and gastrointestinal tracks of Clarias species consumed in Nigeria. Two hundred and sixty (260) Clarias species obtained from River Taraba, Taraba state was examined for the presence of gill and digestive tract parasites. One hundred and forty (140) of them were Clarias gariepinus and one hundred and twenty (120) were Clarias anguillaris. Analysis was carried out using standard parasitological techniques. The gills of the fish were removed and observed under a stereo microscope for parasites. The intestines were cut opened and viewed under the stereo microscope section-by-section. Parasites seen were recovered, fixed, and preserved in 5% formalin before they were later processed. Two gill parasites, Macrogyrodactylus sp. (a monogenean) and Ergasilus sarsi (a copepod) were recovered. The relationship between sex and gill parasite infestation was significant (p&lt;0.05). Three parasite species namely Tetracampos ciliotheca and Monobothroides woodland (cestodes) and Procamallanus laeviconchus (nematode) were recovered from the digestive tract of both Clarias species in the river. Relationships between the sex of fish and digestive tract infestation were also significant (p&lt;0.05).

A new blood parasite of the accentor birds: description, molecular characterization, phylogenetic relationships and distribution.

Haemoproteus bobricklefsi sp. nov. (Haemosporida, Haemoproteidae) was found in the dunnock Prunella modularis and represents the first blood parasite described in accentor birds of the Prunellidae. The description is based on the morphology of blood stages and includes information about a barcoding segment of the mitochondrial cytochrome b gene (lineage hDUNNO01) and the full mitochondrial genome, which can be used for identification and diagnosis of this infection. The new parasite can be readily distinguished from described species of haemoproteids parasitizing passeriform birds due to markedly variable position of nuclei in advanced and fully grown macrogametocytes. Illustrations of blood stages of the new species are given, and phylogenetic analyses based on partial mitochondrial cytochrome b gene sequences and the full mitochondrial genome identified the closely related lineages. DNA haplotype networks showed that transmission occurs in Europe and North America. This parasite was found in the dunnock in Europe and several species of the Passerellidae in North America. It is probably of Holarctic distribution, with the highest reported prevalence in the UK. The parasite distribution seems to be geographically patchy, with preference for areas of relatively cool climates. Phylogenetic analysis suggests that H. bobricklefsi sp. nov. belongs to the Parahaemoproteus subgenus and is probably transmitted by biting midges belonging to Culicoides (Ceratopogonidae). The available data on molecular occurrence indicate that this pathogen is prone to abortive development, so worth attention in regard of consequences for bird health.

Ectoparasite infection levels differ between fish from upwelling-exposed and sheltered rocky reefs areas in Brazil

Ubiquitous and abundant within marine ecosystems, parasites play essential ecological roles such as shaping host population dynamics, altering competition between species, and influencing energy flows through communities. Their diversity and population dynamics are demonstrably shaped by both seasonal and geographic variations. These variations have been often explored at broad spatial scale. However, parasite communities can exhibit significant disparities even at small spatial scales, driven by factors such as wave exposure, temperature fluctuations, and benthic habitat composition. We investigated how crustacean parasites of fish – caligids and gnathiids - differed between two distinct habitats, which are separated solely by a few kilometres, at Arraial do Cabo, Brazil. These two habitats are characterised by a sheltered embayment (hereinafter referred to as “inside”) or an exposed upwelling habitat (hereinafter referred to as “outside”). Individual fish from four species were examined in both habitats. We found that the infestation rate of caligids varied among fish species and, gnathiids varied between the two sampling sites. Gnathiids were absent from fish outside, while they were present on fish inside the embayment. This disparity suggests a critical role of local environmental factors in shaping gnathiid distribution. Potential drivers include temperature fluctuations, substrate composition, and wave exposure, which differed markedly between the two sites. Conversely, caligid parasites infected fish in both locations. While environmental factors may also influence caligid abundance, they appear to exhibit greater tolerance compared to gnathiids. These findings emphasize the importance of incorporating fine-scale environmental heterogeneity when investigating parasite distribution patterns.

Effects of individual characteristics and seasonality and their interaction on ectoparasite load of Daurian ground squirrels in Inner Mongolia, China

Effects of individual characteristics and seasonality and their interaction on ectoparasite load of Daurian ground squirrels in Inner Mongolia, China