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1.
Symbionts and abnormal conditions of razor clam Ensis arcuatus were surveyed in three commercially important natural beds of Galician estuaries (NW Spain). Samples of 15-20 E. arcuatus were collected every 2 months from January 2003 until July 2004 and processed for histological examination. Prokaryote-like colonies, renal coccidians, gregarines, Trichodina sp. ciliates, haplosporidian-like plasmodia, turbelaria, trematode metacercariae, cestode-like larvae and basophilic inclusion bodies were observed in razor clam tissues without causing host damage. Bucephalid digenean sporocysts and germinoma were seen in some samples causing moderate or severe damage to the host depending on the intensity of infection and both could be a cause for concern if prevalence reached epizootic levels in Galician E. arcuatus populations. None of the parasites detected is OIE notifiable and, in general, the commercially exploited beds studied seem to be devoid of serious pathogens.  相似文献   

2.
Outbreaks of tick-borne disease cases in Santa Catarina, Brazil are known, but the presence of the pathogen DNA has never been determined. In this study, the first survey of Anaplasma marginale, Babesia bigemina, and Babesia bovis DNA on blood samples of 33 cattle from an outbreak in Ponte Alta Municipality, Santa Catarina, Brazil, has been carried out. A multiplex PCR detected 54.5% of animals were co-infected with 2 or 3 parasites, while 24.2% were infected with only 1 species. The most prevalent agent was B. bigemina (63.6%) followed by A. marginale (60.6%). This is the first report of tick-borne disease pathogens obtained by DNA analysis in Southern Brazil.  相似文献   

3.
We present the first record in Spanish Mediterranean waters of the protozoan parasite Perkinsus olseni infecting the clam Ruditapes decussatus. Perkinsus infection was detected all year around albeit at a low level of infection intensity. Histological analysis, induction of zoospores and in situ hybridisation assay confirmed the presence of Perkinsus sp. The identity of the parasite was determined by species-specific PCR assay in DNA samples obtained from infected clams. Sequencing of amplified fragments showed 100% identity to the ITS region of P. olseni. We confirmed for the first time the presence of P. olseni in Spanish Mediterranean waters.  相似文献   

4.
The pathological condition of the short-neck clam Ruditapes philippinarum was surveyed along the coast of Kumamoto, Japan, in June 2004. DNA sequences of the non-transcribed spacer region and internal transcribed spacer region flanking 5.8S rRNA identified Perkinsus olseni among the clams. Ray’s fluid thioglycollate medium assay indicated that 96.7% of the clams surveyed from the Kiguchi River tidal flat (native clams, Stn KR-N) and 96.7% of the clams surveyed from the Midori River tidal flat (Stn MR) were infected with P. olseni with an infection intensity of 464,278 and 199,937 Perkinsus cells/gram tissue wet weight (gWW), respectively. In contrast, 66.7% of the clams imported from China and stored along the Kiguchi River tidal flat (Stn KR-I) and 20.2% of clams from the Arao tidal flat (Stn AT) were infected with P. olseni with an infection intensity of 37,547 and 3382 Perkinsus cells/gWW, respectively. Brown ring disease was detected in the clam population from Stn KR-I at a prevalence of 90.0%. Polymerase chain reaction and the 16S rRNA sequence suggested that the agents of brown ring disease observed at Stn KR-I were Vibrio tapetis-like bacteria. Sporocysts and metacercariae of unidentified trematodes were also observed in the gonads and mantle of the clams from Stn KR-I, Stn MR, and Stn AT, at prevalences of 7.1-42.9%. Metacestodes (larval tapeworms) were found in the foot and digestive gland at a prevalence of 52.5%, 30.0%, and 14.3% in clams from Stns MR, AT, and KR-N, respectively. Histology also showed massive hemocyte infiltration and inflammation among clams heavily infected with P. olseni. Castration of the follicle was typical among clams infected with the trematode. The data indicate that most of the clams along the coast of Kumamoto are infected with various pathogens at various rates of infection, and these pathogens could have negative effects on the clam population in the long term.  相似文献   

5.
The subject of the following study was the natural and experimental invasion of trematode larvae in Potamopyrgus antipodarum from Bory Tucholskie National Park (Poland). Only one out of the 14,908 dissected specimens had oval sporocysts and mature cercariae of fish fluke, which belongs to the Sanguinicolidae family. It is the first recorded case in the European population of P. antipodarum living in inland water. The experimental study showed the possibility of native metacercariae (Echinostoma revolutum, Echinoparyphium aconiatum and Hypoderaeum conoideum) settlement in those immigrant snail species; however, exposure to parasites resulted in an increase in snail mortality. The three out of six used cercariae species were able to transform into metacercariae in P. antipodarum as in the second intermediate host, but the exposure to parasitic larvae of four of the used species resulted in an increase in snails’ mortality. It may suggest that not only metacercariae settlement but also the attack of cercariae (Rubenstrema opisthovitellinum at a temperature of 22 °C) affected the low survival of experimental snails in comparison to control animals. The subject of discussion presented in this paper is also the hypothesis on probable effect of the interaction between P. antipodarum and native snail species (as a source of invasive larvae of parasites) living in the same habitat.  相似文献   

6.
7.
This paper reports the parasites found in three commercially exploited bivalve molluscs (Mytella guyanensis, Anomalocardia brasiliana and Iphigenia brasiliana) of an estuarine region of Ilhéus, south of Bahia, Brazil (14°48′23′′S; 39°02′47′′W). Samples of 20 individuals of each species were collected fortnightly from August 2005 to August 2006. A total of 1480 individuals was collected and processed by standard histologic techniques; the histologic sections were stained with Harris haematoxylin and eosin and examined with light microscope. The water temperature in the study area varied from 24 to 30.5 °C and the salinity from 0 to 23 ppt. Remarkable differences were found in the parasitic community between the three mollusc species involved in the study, which occupied different habitats in the estuarine region of the Cachoeira river. The following parasites were found: intracellular rickettsia-like colonies in digestive epithelia; intracellular gregarine Nematopsis sp. in gills, mantle, gonad, digestive gland and foot muscle; sporocysts of a Bucephalidae trematode in gonads, mantle, gills, digestive gland and foot; unidentified digenetic metacercariae in digestive gland and gonad; metacestodes of Tylocephalum sp. in connective tissue in the digestive gland and in gonad; and an unidentified metazoan in mantle and intestinal lumen. No significant temporal variation in the prevalence of any parasite was detected, which could be due to the narrow temperature range of the region and the absence of patterns of salinity and rainfall variation through the year. The infestation by sporocyst was the only pathological threat detected for the studied populations because of its potential for host castration. The low infection intensity and/or prevalence of the other parasites and the lack of obvious lesions suggest that there is no other serious pathological risk for the studied mollusc populations.  相似文献   

8.
A survey was performed to investigate the infection status of freshwater fish with zoonotic trematode metacercariae in Phnom Penh and Pursat Province, Cambodia. All collected fish with ice were transferred to our laboratory and examined using the artificial digestion method. In fish from Phnom Penh, 2 kinds of metacercariae (Opisthorchis viverrini and Haplorchis yokogawai) were detected. O. viverrini metacercariae were positive in 37 (50.0%) of 74 fish in 11 species (average no. metacercariae/fish, 18.6). H. yokogawai metacercariae were detected in 23 (57.5%) of 40 fish in 5 species (average no. metacercariae/fish, 21.0). In fish from Pursat Province, 5 kinds of metacercariae (O. viverrini, H. yokogawai, Haplorchis pumilio, Centrocestus formosanus, and Procerovum sp.) were detected; O. viverrini metacercariae (n=3) in 2 fish species (Henicorhynchus lineatus and Puntioplites falcifer), H. yokogawai metacercariae (n=51) in 1 species (P. falcifer), H. pumilio metacercariae (n=476) in 2 species (H. lineatus and Pristolepis fasciata), C. formosanus metacercariae (n=1) in 1 species (H. lineatus), and Procerovum sp. metacercariae (n=63) in 1 species (Anabas testudineus). From the above results, it has been confirmed that various freshwater fish play the role of a second intermediate host for zoonotic trematodes (O. viverrini, H. yokogawai, H. pumilio, C. formosanus, and Procerovum sp.) in Cambodia.  相似文献   

9.
Three new species of Atopsyche Banks (Hydrobiosidae) from Brazil are described and illustrated: Atopscyhe (Atopsaura) blahniki sp. n., Atopsyche (Atopsyche) parauna sp. n., and Atopsyche (Atopsaura) galharada sp. n. Additional illustrations of the male genitalia of Atopsyche urumarca Schmid are provided, including its populational variation. Also, we provide new state records for 2 species: Atopsyche (Atopsyche) urumarca from São Paulo, and Atopsyche (Atopsaura) plancki Marlier from Santa Catarina.  相似文献   

10.
The metacercarial stage of trematodes is typically considered an encysted, developmentally quiescent, resting stage. Yet the metacercariae of some species of strigeoid trematode undergo extravagant development within specific tissues of their second intermediate host. Our understanding of patterns of migration, site selection and development of these types of metacercariae is known for only a few species. In this study, we characterize the invasion and development of Ornithodiplostomum sp. metacercariae in their second intermediate host, the fathead minnow, Pimephales promelas. Diplostomules completed their migration into the abdominal cavity between 15 min and 48 h p.i. Most diplostomules migrated along muscular and connective tissue then penetrated the peritoneal lining of the abdominal cavity en route to the liver or pancreas. Alternatively, some diplostomules migrated within the host’s circulatory system, including the heart and arteries of the hepatic portal system. Metacercarial development in the liver and pancreas involved distinct growth, encystment and consolidation phases. Metacercarial volume increased 15-fold between 48 h and 4 weeks p.i., presumably due to absorptive and/or ingestive feeding activities within host tissues. By 2 weeks p.i., metacercariae were enveloped within a cyst wall and they were found loosely attached to the surfaces of internal tissues or unattached within the body cavity. These results emphasize the complex nature of metacercarial migration and growth and demonstrate that their growth and encystment phases occur within different habitats within their intermediate hosts.  相似文献   

11.
Ambrosia beetles (Coleoptera: Scolytinae) are associated with strictly entomochoric and mutualistic fungi. We studied the mycobiota associated with Scolytodes unipunctatus, ambrosia beetles that infest Cecropia trees in Central America. Isolates were characterized using morphology and rDNA sequences (ITS region, LSU, and SSU rDNA). Four species are described here: Raffaelea scolytodis sp. nov. (Ophiostomatales), Gondwanamyces scolytodis sp. nov., Custingophora cecropiae sp. nov., and Graphium sp. (Microascales). The genus Custingophora is emended to include Knoxdaviesia anamorphs of Gondwanamyces based on uniformity of DNA sequences and phenotype.  相似文献   

12.
13.
In nature, parasite transmission from one host to the next takes place within complex biotic communities where non-host organisms can reduce transmission rates, for instance by preying on infective stages. We experimentally investigated the impact of four very different non-host organisms on the transmission of the microphallid trematode Maritrema novaezealandensis from its snail first intermediate host to its crustacean second intermediate host. We show that in laboratory mesocosms, accumulation of parasites in juvenile stalk-eyed mud crabs, Macrophthalmus hirtipes (Ocypodidae), was not reduced in the presence of cockles, Austrovenus stutchburyi, barnacles, Balanus sp., or the algae Enteromorpha spp., three organisms whose feeding mode or general abundance could negatively impact the parasite's infective stages (cercariae). In contrast, the presence of the anemone Anthopleura aureoradiata in the mesocosms caused a more than 4-fold reduction in the number of parasites acquired by crabs when compared to control mesocosms. Observations on fluorescent-dyed cercariae confirmed that they are ingested by anemones. Given the often high densities of anemones on mudflats, they may represent an important regulator of the abundance of M. novaezealandensis, and thus of the impact of this parasite on its hosts. These anemones may decrease cercarial transmission for many other trematode species as well. Our results stress the need for studies of parasite transmission in natural contexts rather than under simplified laboratory conditions.  相似文献   

14.
The genera Haplocytheridea and Cytheridea have Tethyan origins and a wide paleobiogeographic and stratigraphic distribution, ranging from the Cretaceous to Recent. Both of them have been recorded in northern South America, but only Cytheridea has been found in the northern Cretaceous basins of Brazil. The genus Haplocytheridea is recorded, for the first time, in the Early Miocene deposits of the Pirabas Formation of northern Brazil, from a 20 m-thick succession of carbonate and argillaceous rocks deposited in lagoonal and restricted platform environments. Among the ten Haplocytheridea species identified, four are new: H. variopunctata n. sp., H. sandbergi n. sp., H. pirabasensis n. sp. and H. sinuosa n. sp. In addition, three new species of Cytheridea are also described: C. coimbrai n. sp., C. pirabasensis n. sp. and C. purperae n. sp. The highest frequencies and abundances of both genera, in the studied section, are thought to be associated with nearshore to brackish water settings.  相似文献   

15.
Elixothrips brevisetis (Bagnall), a species exotic to Brazil, is first recorded in the country. Individuals were collected on banana fruits (Musa sp.) (Musaceae) in July 2010 in the municipality of Luís Alves, state of Santa Catarina, causing rusting on the fruit peel in several bunches of bananas.  相似文献   

16.
Many Koreans usually eat raw pond smelts, Hypomesus olidus, in the winter. This study was performed to evaluate the infection status with trematode metacercariae in pond smelts from January 1998 through February 1999. Among 1,305 fish collected, 459 were purchased from wholesale dealers in Chinchon-gun, Chungchongbuk-do, and the rest of them were caught with a casting net in Soyangho (Lake), Taehoman (Bay) and Paekkokchosuchi (Pond). Seven species of trematode metacercariae including two unidentified ones were detected from 1,305 pond smelts. The number of detected trematode metacercariae according to the species are as follow: Clonorchis sinensis 8, Holostephanus nipponicus 7, Cyathocotyle orientalis 24, Diplostomum sp. 14, and Metorchis orientalis 7. From the above results, it was confirmed that H. olidus plays a role as the second intermediate host of some kinds of trematode including C. sinensis in Korea. Our report shows possible clonorchiasis caused by eating raw pond smelts.  相似文献   

17.
Lonchocarpus castaneifolius, L. grazielae, L. longiunguiculatus, and L. montanus from Brazil are described and illustrated based on field and herbarium studies. The first species belongs to Lonchocarpus sect. Punctati and is restricted to northeastern Brazil (Bahia state). The other three are included in sect. Laxiflori. Lonchocarpus grazielae is restricted to the southern coastal region (Santa Catarina state), L. montanus is found in northeastern Brazil (Bahia and Piauí states), the west-central region (Goiás and Tocantins states) and the southeast (Minas Gerais state), and L. longiunguiculatus occurs in northeastern (Bahia state) and southeastern (Minas Gerais state) Brazil.  相似文献   

18.
Two related perciform fish species of the subfamily Monotaxinae (Sparoidea: Lethrinidae) Gymnocranius superciliosus sp. nov. and Gymnocranius satoi sp. nov. are described from specimens and tissue samples from the Coral Sea and adjacent regions. G. superciliosus sp. nov. is distinct from all other known Gymnocranius spp. by the following combination of characters: body elongated (depth 2.7–3.1 in standard length), caudal fin moderately forked with a subtle middle notch, its lobes slightly convex inside, distinctive blackish eyebrow, snout and cheek with blue speckles, and dorsal, pectoral, anal and caudal fins reddish. G. satoi sp. nov. is the red-finned ‘Gymnocranius sp.’ depicted in previous taxonomic revisions. While colour patterns are similar between the two species, G. satoi sp. nov. is distinct from G. superciliosus sp. nov. by the ratio of standard length to body depth (2.4–2.5 vs. 2.7–3.1) and by the shape of the caudal fin, which is more shallowly forked, its lobes convex inside and their extremities rounded. The two species are genetically distinct from each other and they are genetically distinct from G. elongatus, G. euanus, G. grandoculis, and G. oblongus sampled from the Coral Sea and adjacent regions.  相似文献   

19.
The pathogenicity and morphology of a large Babesia species, Babesia sp. Xinjiang, are described here. The parasite has very low virulence for sheep, and caused no detectable clinical symptoms. Splenectomized sheep infected with the parasite showed mild fever and low parasitemia and would recover gradually. If splenectomized sheep were immuno-suppressed with dexamethasone, the parasitemia could reach 8.5%, and death occurred. A splenectomized calf could not be infected with the Babesia species. Paired parasites were the typical form of the Babesia species in erythrocytes and the average size of a pair of parasites was 2.42 (±0.35) μm × 1.06 (±0.22) μm. Merozoites were found in the gut, salivary gland, haemolymph, ovary and eggs of female Hyalomma anatolicum anatolicum engorged on sheep infected with the parasites. The results of experimental transmission showed that the larval, nymph and adult stages of H. a. anatolicum could transmit the Babesia species to sheep.  相似文献   

20.
Two new species, Xenotarsonemus quiriri n. sp. and Xenotarsonemus scorpius n. sp., are described and illustrated in this paper based on specimens collected on Myrtaceae plants in Atlantic Forest areas of the states of Bahia and Santa Catarina, Brazil. A key to identification of Xenotarsonemus species reported from Brazil is provided.  相似文献   

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