Evidence Of Parasitism Research Articles

Prospects for Biological Control of Macadamia Felted Coccid in Hawaii with Metaphycus macadamiae Polaszek & Noyes, a New Encyrtid Wasp Native to New South Wales, Australia.

Macadamia felted coccid (MFC), Acanthococcus ironsidei (Williams) (Hemiptera: Eriococcidae), was first discovered in 2005 on the Island of Hawaii. Host plants are restricted to Macadamia species, with Macadamia integrifolia Maiden & Betche (Proteaceae) being grown in Hawaii for nut production. Approximately 6839 hectares macadamia nuts are harvested in Hawaii with an estimated farm value of USD 48.8 million (2019-2020 records). Exploration in Australia started in November 2013 for the evaluation of potential parasitoids being host specific for introduction into Hawaii. A dominant solitary endoparasitoid of MFC from New South Wales was discovered and described as Metaphycus macadamiae Polaszek & Noyes sp. n (Hymenoptera: Encyrtidae: Encyrtinae). Biology and host specificity testing were conducted at the Hawaii Department of Agriculture, Insect Containment Facility, on nine hemipteran and three lepidopteran eggs. Results indicated that M. macadamiae is host specific to MFC. There has been no evidence of parasitism or host feeding on any of the non-target insect hosts that were tested. Parasitoid emergence from the control (MFC) averaged 30.2% compared to 0% on non-target hosts. A low rate of parasitoid emergence in the laboratory (average 30.2%) and an increased rate of MFC nymphal mortality was due to adult feeding. Field parasitism reached up to 32.7% emergence in Alstonville, New South Wales, Australia. We report on the parasitoid performance in native Australia, rearing biology, host specificity testing, and the extant natural enemies associated with MFC in Hawaii. A petition to release this parasitoid for the biocontrol of MFC in Hawaii is pending. Once permitted for release, the colony will be shared with South African Mac Nut Association for their biocontrol program of this invasive pest. They will conduct their own testing before approval for release.

Nutrient composition and microbial food safety of a locally-processed fish product in Cambodia

AbstractPrahoc is a traditional, fermented fish product in Cambodian diets. Fermented products like Prahoc may play a range of beneficial roles nutritionally, culturally, and financially. However, the use of freshwater fish and long-term storage may also pose food safety risks of parasites and microorganisms. We conducted a mixed-methods study of Prahoc to describe the complex risks and benefits of this food that included semi-structured interviews (prahoc-producing households, n = 22; small and medium enterprises n = 6), production observation, sample collection and analysis of nutrient composition and food safety parameters. Nutrient composition analysis showed that while Prahoc contributes small amounts of zinc, iron, and other key minerals to the diet, it is also very high in sodium (∼101,621 mg kg-1). Food safety analyses showed that while further tests are needed to resolve Listeria monocytogenes, Salmonella spp., and Vibrio risks, all samples were in compliance with the Cambodia Standards for Prahoc, and there was no evidence of parasites. Participants described Prahoc as playing an essential dietary and cultural role, and also making important contributions to household welfare, particularly within households and businesses that sold Prahoc. Despite the potential risks of microbial food safety and high sodium intake, Prahoc production offers benefits by adding value to fresh fish, reducing loss and waste, and preserving the harvest. However, Prahoc production depends on fish availability and is limited by declining access and high prices. Thus, freshwater fisheries management should take into account Prahoc production activities, an important value chain activity that contributes to the livelihoods of rural Cambodian communities.

From spatial pattern to ecological process through imaging zooplankton interactions

Abstract Ecological interactions among marine zooplankton are poorly described because conventional sampling gears, such as plankton nets and traps, obscure the physical and biological environment that individuals experience. With in situ imagery, however, it is possible to resolve these interactions and potentially convert snapshot distributions into process-oriented oceanographic and ecological understanding. We describe a variety of imagery-detected ecological interactions with high spatial resolution in the northern Gulf of Mexico shelf waters (20–35 m bottom depth), providing new evidence of parasitism, predation, and life stage spatial structuring for different zooplankton groups. Chaetognaths were infected with an anteriorly attached, parasitic polychaete (1.1% of 33 824 individuals), and these infected chaetognaths were more common further offshore, south of a nearshore patch where unparasitized individuals reached concentrations of ∼90 m–3. Predation by Liriope spp. hydromedusae tended to occur in the shallowest 10–15 m, and doliolids formed distinct patches of different life stages, indicating that the environment is replete with sharp transitions among various ecological processes. Similar patterns in other marine ecosystems likely exist, and we encourage hybrid (machine/human expertise) approaches that broaden the scope for analysis of plankton images, which are rich sources of new ecological information and hypotheses yet to be examined quantitatively.

Characterization of the substrate binding site of an iron detoxifying membrane transporter from Plasmodium falciparum

BackgroundPlasmodium species are entirely dependent upon their host as a source of essential iron. Although it is an indispensable micronutrient, oxidation of excess ferrous iron to the ferric state in the cell cytoplasm can produce reactive oxygen species that are cytotoxic. The malaria parasite must therefore carefully regulate the processes involved in iron acquisition and storage. A 273 amino acid membrane transporter that is a member of the vacuolar iron transporter (VIT) family and an orthologue of the yeast Ca2+-sensitive cross complementer (CCC1) protein plays a major role in cytosolic iron detoxification of Plasmodium species and functions in transport of ferrous iron ions into the endoplasmic reticulum for storage. While this transporter, termed PfVIT, is not critical for viability of the parasite evidence from studies of mice infected with VIT-deficient Plasmodium suggests it could still provide an efficient target for chemoprophylactic treatment of malaria. Individual amino acid residues that constitute the Fe2+ binding site of the protein were identified to better understand the structural basis of substrate recognition and binding by PfVIT.MethodsUsing the crystal structure of a recently published plant VIT as a template, a high-quality homology model of PfVIT was constructed to identify the amino acid composition of the transporter’s substrate binding site and to act as a guide for subsequent mutagenesis studies. To test the effect of mutation of the substrate binding-site residues on PfVIT function a yeast complementation assay assessed the ability of overexpressed, recombinant wild type and mutant PfVIT to rescue an iron-sensitive deletion strain (ccc1∆) of Saccharomyces cerevisiae yeast from the toxic effects of a high concentration of extracellular iron.ResultsThe combined in silico and mutagenesis approach identified a methionine residue located within the cytoplasmic metal binding domain of the transporter as essential for PfVIT function and provided insight into the structural basis for the Fe2+-selectivity of the protein.ConclusionThe structural model of the metal binding site of PfVIT opens the door for rational design of therapeutics to interfere with iron homeostasis within the malaria parasite.

Ecology and epidemiology of the striped shrimp, Pandalus montagui Leach, 1814 (Decapoda: Caridea), in the northern Labrador Sea, Davis Strait, and Ungava Bay, Canada

Abstract Despite a fishery with annual landings valued at over $50 million CAD, very little knowledge has been gathered about the ecology of the striped shrimp (Pandalus montagui Leach 1814) in the Canadian northwestern Atlantic. This information is nevertheless considered essential for developing appropriate management actions for the fishery. We used survey data collected from 2005 to 2020 in the northern Labrador Sea, Ungava Bay, and Davis Strait to examine sizes, stages of maturity, size of transition, and evidence of parasites in the striped shrimp. We also investigated potential ecological drivers affecting the presence of parasites and size of transition. We found shrimp were substantially larger than previously observed in nearby habitats. The size of transition did not remain constant throughout the time series, and instead, was a function of the average size of females and the amount of preferred habitat in the previous year. The probabilities of individuals exhibiting black gill or black shell disease, or being infected with a bopyrid parasite were generally related to sex, depth, temperature, salinity, latitude, and shrimp density. The large sizes observed in the study area and the apparent plasticity of the population to environmental changes indicate that this species should be closely monitored in the future in relation to exploitation pressure and climate change.

Establishment, spread, and impact of an invasive planthopper on its invasive host plant: Prokelisia marginata (Homoptera: Delphacidae) exploiting Spartina anglica (Poales: Poaceae) in Britain

1. Since its recent arrival in Britain, the planthopper Prokelisia marginata has spread widely around saltmarshes on the east and south coast of England and south Wales, feeding on Common Cordgrass, Spartina anglica, itself an invasive non‐native species.2. Results suggest that P. marginata populations in Britain benefit from a degree of natural enemy release. No evidence of parasitism was found in over 71 000 eggs, nymphs, and adults inspected. The only potential natural enemy control was suggested by a positive correlation between the densities of planthoppers and generalist spiders.3. Experimental exposure under both glasshouse and field conditions to typical field densities of planthoppers resulted in significant negative effects on a number of host plant performance metrics.4. Spartina anglica is important for stabilising estuarine sediments and has been deliberately planted for this purpose in the past. Its weakening as a result of heavy planthopper herbivory could have serious consequences for the long‐term stability of Britain's vulnerable saltmarsh habitats.

An encrusting kleptoparasite-host interaction from the early Cambrian

Parasite–host systems are pervasive in nature but are extremely difficult to convincingly identify in the fossil record. Here we report quantitative evidence of parasitism in the form of a unique, enduring life association between tube-dwelling organisms encrusted to densely clustered shells of a monospecific organophosphatic brachiopod assemblage from the lower Cambrian (Stage 4) of South China. Brachiopods with encrusting tubes have decreased biomass (indicating reduced fitness) compared to individuals without tubes. The encrusting tubes orient tightly in vectors matching the laminar feeding currents of the host, suggesting kleptoparasitism. With no convincing parasite–host interactions known from the Ediacaran, this widespread sessile association reveals intimate parasite–host animal systems arose in early Cambrian benthic communities and their emergence may have played a key role in driving the evolutionary and ecological innovations associated with the Cambrian radiation.

Overwinter Parasitism of Callosamia promethea (Drury) (Saturniidae) (Promethea Moth) in a Northern Hardwood Forest

The giant silk moth Callosamia promethea (Promethea Moth) overwinters as pupae in cocoons spun in hanging leaves. Even though they are camouflaged, moths at this developmental stage are vulnerable to parasitism and predation, both of which are relevant to local population abundance and persistence. Our study documented the fates of overwintering Promethea Moths near Weld, ME, during 7 winters from 1997 to 2017. Our collection and dissection of 923 cocoons revealed that moth emergence declined from 47% to 10% over the study period. Parasitism by 2 native species of ichneumonid wasp (Gambrus nuncius and Enicospilus americanus) was the dominant cause of mortality, accounting for 59% of Promethea Moth pupal death. Predation accounted for less than 4% of mortality. Our results provide evidence of parasitism as a major contributor to mortality of Promethea Moth pupae.

Hematology – A diagnostic tool in cases of splenomegaly

Objective: To study hematological profile in patients with clinically palpable spleen and to find out the role of hematological investigations as a diagnostic tool in elucidating etiopathogenesis of splenomegaly. Materials and methods: This cross-sectional study was conducted on 50 patients at a teaching hospital from Aug 2011 to 2013. Detailed clinical history including name, age, sex, chief complaints, clinical findings, X-ray and USG (if done) were noted. Grading of splenomegaly was done by Hackett's classification. Laboratory tests including peripheral blood smear, complete blood count and bone marrow examination (if required) were performed. Results: In the present study, maximum numbers of patients were males in the age group of 0-15 years. The commonest cause of splenomegaly found was acute leukemia followed by malaria, hemolytic anemia, chronic myeloid leukemia, liver cirrhosis and infections. Hematological causes were the most common etiology of splenomegaly in this study. The commonest grade of splenomegaly was I and II (mild). There was also a case of congenital dyserythropoietic anemia type I (CDA), a rare autosomal recessive disorder. We also came across one case of plasmodium falciparum malaria with no evidence of parasite on peripheral blood smear which called for bone marrow study. Conclusion: Splenomegaly is a subject of considerable clinical concern as spleen is not palpable under normal circumstances. When palpable, it may be associated with serious disorders from which no age is exempted. Thus, hematological evaluation becomes necessary to understand the etiopathogenesis of splenomegaly.

Human Parasites in Medieval Europe: Lifestyle, Sanitation and Medical Treatment.

Parasites have been infecting humans throughout our evolution. However, not all people suffered with the same species or to the same intensity throughout this time. Our changing way of life has altered the suitability of humans to infection by each type of parasite. This analysis focuses upon the evidence for parasites from archaeological excavations at medieval sites across Europe. Comparison between the patterns of infection in the medieval period allows us to see how changes in sanitation, herding animals, growing and fertilizing crops, the fishing industry, food preparation and migration all affected human susceptibility to different parasites. We go on to explore how ectoparasites may have spread infectious bacterial diseases, and also consider what medieval medical practitioners thought of parasites and how they tried to treat them. While modern research has shown the use of a toilet decreases the risk of contracting certain intestinal parasites, the evidence for past societies presented here suggests that the invention of latrines had no observable beneficial effects upon intestinal health. This may be because toilets were not sufficiently ubiquitous until the last century, or that the use of fresh human faeces for manuring crops still ensured those parasite species were easily able to reinfect the population.

Taphonomic considerations of a whipworm infection in a mummy from the Dominican Church of the Holy Spirit, Vilnius, Lithuania

In the present study, the abdominal contents of 10 mummies from beneath the Dominican Church of the Holy Spirit in Vilnius, Lithuania, were examined for the presence of helminth parasites using standard archaeoparasitological techniques. Of the mummies examined, only one individual presented with evidence of parasitism. This individual was infected with both Trichuris trichiura and Ascaris lumbricoides (5,222 parasite eggs/gram). The conditions of many of the T. trichiura eggs suggest that a fortuitously embedded female whipworm decomposed within the individual's gut to release the eggs, as opposed to the eggs actually being passed by the adult helminth. This study highlights a taphonomic issue unique to mummies by demonstrating the differential preservation of parasite eggs existing in various stages of development. Whenever one is not dealing with parasite eggs that have already been passed by the host, as is the case when analyzing intestinal tissues, one must understand that some types of parasite eggs may not be fully formed. It is imperative, as demonstrated by our findings, that researchers have the knowledge to recognize under-developed intestinal helminth eggs in addition to fully formed intestinal helminth eggs from mummy source materials. Together, these findings demonstrate the persistence of these helminth parasites in Europe during the 18th and 19th centuries and represent the first archaeoparasitological evidence from mummies in Vilnius, Lithuania.

Outbreak of Cutaneous Leishmaniasis in Fuenlabrada, Madrid

BackgroundLeishmaniasis, an endemic infection in Spain, is caused by protozoan parasites of the Leishmania genus. Between 2010 and 2012, there was an outbreak of cutaneous and visceral leishmaniasis in Fuenlabrada, Madrid. ObjectivesTo describe the cases of cutaneous leishmaniasis diagnosed over a 17-month period at the dermatology department of Hospital de Fuenlabrada. Material and methodsWe analyzed the epidemiological, clinical, histological, and microbiological features of each case and also evaluated the treatments administered and outcomes. ResultsWe studied 149 cases. The incidence of cutaneous leishmaniasis showed a peak in the age range between 46 and 60 years and was similar in men and women. At the time of consultation, the lesions had been present for between 2 and 6 months in the majority of patients. The most common clinical presentation was with erythematous plaques and papules without crusts (52% of cases). Lesions were most often located in sun-exposed areas and were multiple in 57% of patients. In 67% of cases, the histological study showed non-necrotizing granulomatous dermatitis with no evidence of parasites using conventional staining methods. Diagnosis was confirmed by polymerase chain reaction (PCR) in 98% of patients. In the remaining cases, the histological study revealed Leishman-Donovan bodies in the skin. Intralesional pentavalent antimonials were the most commonly used drugs (76% of cases) and produced satisfactory results. ConclusionsWe have presented a large series of cases of cutaneous leishmaniasis diagnosed in the context of an outbreak. Multiple papules were the most common clinical presentation, with histology that showed non-necrotizing granulomatous dermatitis with no evidence of parasites. PCR of skin samples was the test that most frequently provided the diagnosis.

Brote de leishmaniasis cutánea en el municipio de Fuenlabrada

IntroductionLeishmaniasis, an endemic infection in Spain, is caused by protozoan parasites of the Leishmania genus. Between 2010 and 2012, there was an outbreak of cutaneous and visceral leishmaniasis in Fuenlabrada, Madrid. ObjectivesTo describe the cases of cutaneous leishmaniasis diagnosed over a 17-month period at the dermatology department of Hospital de Fuenlabrada. Material and methodsWe analyzed the epidemiological, clinical, histological, and microbiological features of each case and also evaluated the treatments administered and outcomes. ResultsWe studied 149 cases. The incidence of cutaneous leishmaniasis showed a peak in the age range between 46 and 60 years and was similar in men and women. At the time of consultation, the lesions had been present for between 2 and 6 months in the majority of patients. The most common clinical presentation was with erythematous plaques and papules without crusts (52% of cases). Lesions were most often located in sun-exposed areas and were multiple in 57% of patients. In 67% of cases, the histological study showed non-necrotizing granulomatous dermatitis with no evidence of parasites using conventional staining methods. Diagnosis was confirmed by polymerase chain reaction (PCR) in 98% of patients. In the remaining cases, the histological study revealed Leishman-Donovan bodies in the skin. Intralesional pentavalent antimonials were the most commonly used drugs (76% of cases) and produced satisfactory results. ConclusionsWe have presented a large series of cases of cutaneous leishmaniasis diagnosed in the context of an outbreak. Multiple papules were the most common clinical presentation, with histology that showed non-necrotizing granulomatous dermatitis with no evidence of parasites. PCR of skin samples was the test that most frequently provided the diagnosis.

Do intestinal parasitic infestations in patients with clinically acute appendicitis increase the rate of negative laparotomy? Analysis of 3863 cases from Turkey.

IntroductionAcute appendicitis is the most frequently observed disease requiring emergency surgery. The role of parasites in its pathogenesis has long been discussed. The signs of the parasitic infestations can mimic the signs of acute appendicitis. Therefore, it can cause a negative laparotomy.AimTo evaluate the parasitic infestations of the appendix vermiformis whether increas the rate of negative laparotomy.Material and methodsThe histopathology results of a total of 3863 patients who underwent appendectomy with clinically acute appendicitis were evaluated retrospectively. All appendectomy materials in which parasites were observed were evaluated with respect to the nature of the parasites and the findings of inflammation. Cases in which parasite tissue fragments and/or eggs as well as findings of inflammation were histopathologically observed in the appendix lumen were diagnosed with parasitic appendicitis.ResultsEvidence of parasites was observed in 19 (0.49%) of the evaluated appendectomy materials. In 9 (47.3%) of these specimens that had evidence for parasites, findings for acute appendicitis and localized peritonitis were identified. Findings of acute appendicitis had not been identified in the other ten (52.7%) of the specimens. Enterobius vermicularis was the most frequently identified parasite.ConclusionsIn parasitic acute appendicitis, appendectomy in itself is not sufficient for treatment. Pharmacological treatment should also be administered after surgery. Patients should be evaluated prior to surgery for parasites, and diagnosis of acute appendicitis should be considered more cautiously in order to avoid negative laparotomies.

Eosinophilic Gastroenteritis: A Case of Mistaken Identity

Introduction: Eosinophilic gastroenteritis (EG) is an uncommon disorder characterized by either local or diffuse eosinophilic infiltration of the gastrointestinal (GI) tract. Clinical presentation varies depending on the anatomical location and layer of the GI tract involved. We report a case of EG misdiagnosed as Common variable immunodeficiency (CVID). Case Report: A 23-year-old male diagnosed with CVID was referred for chronic diarrhea, abdominal pain, and hypoalbuminemia. He had recurrent bronchitis and sinusitis which led to his diagnosis of CVID. Monthly gammaglobulin infusions were started, however, the regimen was changed to every three weeks due to persistently low serum immunoglobulins. He denied drug and food allergies and had no other allergic conditions. Physical examination revealed 1+ pedal edema and was otherwise normal. Laboratory studies revealed a white blood cell count of 6.6 K/μl with absolute eosinophils of 1881 cells/μL (15-500), hemoglobin of 13.3 g/dl and platelets of 256 K/μl. Serum albumin was 2.8 g/dl and total protein was 5.4 g/dl. Serum IgG was 223 mg/dl (700-1600), IgA 58 mg/dl (70-400) and IgM 36 mg/dl (40-230). Autoimmune panel, quantiferon gold, celiac serology and stool studies were negative. Endoscopic evaluation found esophagitis, superficial erosions in the antrum, and duodenitis. Pathology revealed active gastritis with increased eosinophils >100/hpf and muscularis mucosa involvement, eosinophilic esophagitis with >58 eosinophils/hpf, and eosinophilic microabscesses. Helicobacter pylori was not identified. The duodenum exhibited aggregates of esoinophils in the lamina propria (16-18/hpf) with normal villous architecture. No evidence of parasites was noted. Prednisone 50 mg/day was started for EG with a taper by 10 mg every 4 weeks. At 8 week follow-up, he had normalization of his eosinophil count, serum albumin and immunoglobulins. Follow up endoscopy and biopsies of the stomach and esophagus were normal. Discussion: Eosinophilic gastroenteritis is a rare condition involving eosinophilic infiltrates in the gastrointestinal tract. Classification is based on maximal depth of tissue involvement: mucosal, muscle layer or subserosal layer. Clinical features vary based on the region and depth of eosinophilic infiltration. Current knowledge of treatment is derived mostly from small studies and anecdotal experience using dietary therapy, steroids, mast cell inhibitors, leukotriene receptor antagonists, surgery, and biologics. The natural history is not well described but clinical studies show that 40% patients have spontaneous remission without relapse after treatment and 50% have a more complex, chronic course characterized by unpredictable relapses.

These Squatters Are Not Innocent: The Evidence of Parasitism in Sponge-Inhabiting Shrimps

Marine sponges are frequently inhabited by a wide range of associated invertebrates, including caridean shrimps. Symbiotic shrimps are often considered to be commensals; however, in most cases, the relationship with sponge hosts remains unclear. Here we demonstrate that sponge-inhabiting shrimps are often parasites adapted to consumption of sponge tissues. First, we provide detailed examination of morphology and stomach contents of Typton carneus (Decapoda: Palaemonidae: Pontoniinae), a West Atlantic tropical shrimp living in fire sponges of the genus Tedania. Remarkable shear-like claws of T. carneus show evidence of intensive shearing, likely the result of crushing siliceous sponge spicules. Examination of stomach contents revealed that the host sponge tissue is a major source of food for T. carneus. A parasitic mode of life is also reflected in adaptations of mouth appendages, in the reproduction strategy, and in apparent sequestration of host pigments by shrimp. Consistent results were obtained also for congeneric species T. distinctus (Western Atlantic) and T. spongicola (Mediterranean). The distribution of shrimps among sponge hosts (mostly solitary individuals or heterosexual pairs) suggests that Typton shrimps actively prevent colonisation of their sponge by additional conspecifics, thus protecting their resource and reducing the damage to the hosts. We also demonstrate feeding on host tissues by sponge-associated shrimps of the genera Onycocaris, Periclimenaeus, and Thaumastocaris (Pontoniinae) and Synalpheus (Alpheidae). The parasitic mode of life appears to be widely distributed among sponge-inhabiting shrimps. However, it is possible that under some circumstances, the shrimps provide a service to the host sponge by preventing a penetration by potentially more damaging associated animals. The overall nature of interspecific shrimp-sponge relationships thus warrants further investigation.

Up Regulation of the Maternal Immune Response in the Placenta of Cattle Naturally Infected with Neospora caninum

Neospora caninum is an intracellular protozoan parasite which is a major cause of abortion in cattle worldwide. It forms persistent infections which recrudesce during pregnancy leading to foetal infection and in a proportion of cases, abortion. The mechanisms underlying abortion are not understood. In this study, recrudescence of a persistent infection in eight naturally infected cows occurred between 20 and 33 weeks of gestation. Animals were killed at the time of recrudescence and parasites were detected in the placentae and foetuses. An active maternal immune response consisting of an infiltration of CD4+ and CD8+ T cells and a 46–49 fold increase in interferon-γ and interleukin-4 mRNA was detected. Other cytokines, notably interleukin-12 p40, interleukin-10 and tumour necrosis factor-α were also significantly increased and Major Histocompatibility Class II antigen was expressed on maternal and foetal epithelial and stromal fibroblastoid cells. Significantly, despite the presence of an active maternal immune response in the placenta, all the foetuses were alive at the time of maternal euthanasia. There was evidence of parasites within foetal tissues; their distribution was restricted to the central nervous system and skeletal muscle and their presence was associated with tissue necrosis and a non-suppurative inflammatory response involving lymphocytes and macrophages, irrespective of the gestational age of the foetus. Whilst an active maternal immune response to a pathogen in the placenta is generally considered to be damaging to the foetal trophoblast, our findings suggest that the presence of a parasite-induced maternal immune response in the placenta is not detrimental to foetal survival but may contribute to the control of placental parasitosis.

Response of Birds in Tropical Deciduous Forest to Brown-Headed Cowbirds (Molothrus ater)

Abstract During June–September 2007, we searched bird nests for evidence of parasitism by brown-headed cowbirds (Molothrus ater) and we tested response of the avian community to taxidermy mounts of a brown-headed cowbird in a tropical deciduous forest in the Chamela-Cuixmala Biosphere Reserve in western Mexico. Of 46 nests found (black-capped gnatcatcher Polioptila nigriceps, 2; red-breasted chat Granatellus venustus, 1; blue bunting Cyanocompsa parellina, 1; orange-breasted bunting Passerina leclancherii, 1; rufous-backed thrush Turdus rufopalliatus, 1; yellow-green vireo Vireo flavoviridis, 39), only one was parasitized (nest of a black-capped gnatcatcher). Experimental responses to taxidermy mounts suggested that yellow-green vireos may have had previous contact with cowbirds. We conclude that in the Chamela-Cuixmala Biosphere Reserve, parasitism by brown-headed and bronzed cowbirds (Molothrus aeneus) remains low, or even absent for some species, as on the yellow-green vireo, but this situation could c...

Cutaneous and Tendon Sheath Mastocytomas with Eosinophilic Joint and Tendon Sheath Effusions in a Horse

Cutaneous and Tendon Sheath Mastocytomas with Eosinophilic Joint and Tendon Sheath Effusions in a Horse

First fossil record of parasitism in Devonian calcareous sponges (stromatoporoids)

Palaeozoic calcareous sponges (stromatoporoids) are common bio-constructing fossils; they are sometimes found in association with helicoidal structures of unknown biological affinities. The interaction between the tube-forming organisms has usually been classified as commensalism. About 260 stromatoporoid skeletons from the Middle Devonian (Givetian) of the Mont d'Haurs section near Givet (Champagne-Ardenne, France) were thin-sectioned and analysed under transmitted light. Approximately 10% of the examined stromatoporoids (mainly belonging to the genera Actinostroma, Stromatopora and Stromatoporella) contain tubes classified as Torquaysalpinx sp. The Torquaysalpinx organisms penetrated the skeletons of stromatoporoids in vivo (as evidenced by skeletal overgrowths); around the infesting organisms, growth bands are bent down. Diminished growth rates around the infesting organism demonstrate a negative influence on the host, similar to that seen in the modern demosponge-polychaete association of Verongia-Haplosyllis. This is demonstrated by changes in growth bands. As in the above-mentioned association, the endosymbiont might have been feeding directly upon the tissues of the host. The Torquaysalpinx organisms were gaining habitat and possibly also food resources - for them this interaction was clearly positive. This long-term association can therefore be classified as parasitism. This is the first evidence for parasitism in Palaeozoic sponges.