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1.
We examined the gills of wild fish collected from central Texas for Centrocestus formosanus metacercariae to determine whether this temperature-restricted parasite had invaded the thermally dynamic Guadalupe River via an introduced population in its thermally stable tributary, the Comal River. We collected fish from three sites in the Guadalupe River near its confluence with the Comal River (upstream, at, and downstream) and one site in the Comal River. Centrocestus formosanus infected 14 of the 25 species examined (56.0%) and 171 of the individual fish (27.1%). Several of the infected fish represent new host records for the parasite, and two are listed as species of special concern by the state of Texas. Mean metacercarial intensities varied from 8 to 616 among species, and the highest recorded intensity was greater than 800 in two Guadalupe roundnose minnow Dionda nigrotaeniata. Among the 24 species examined from the Guadalupe River, 11 (45.8%) were infected with C. formosanus. Thorough surveys at the study sites yielded no living specimens of the first obligate intermediate snail host (red-rim melania Melanoides tuberculatus), which must be present to perpetuate the parasite. Thus, the infections were probably due to drifting cercariae that had been shed into the water column upstream of the study area in the Comal River. We therefore investigated spatial patterns in cercarial acquisition using caged fish to determine whether drifting cercariae were present in the water column at the study sites. Of 57 uninfected blacktail shiners Cyprinella venusta exposed to Guadalupe River water downstream from and at the confluence, 52 (91.2%) became infected with C. Formosanus metacercariae at a mean rate of 4 metacercariae/d. This finding extends the known geographic range of this invasive exotic parasite and is the first report of the life cycle being advanced in the fish assemblage of a thermally variable temperate stream in the USA. 相似文献
2.
One trematode, Echinostoma macrorchis, 2 cestodes, Hymenolepis diminuta and Choanotaenia spasskii and 5 nematodes, Parastrongyloides winchesi, Tricholinstowia talpae, Heterakis spumosa, Trichuris sp. and Capillaria soricis were obtained from 129 Mogera wogura, 233 M. kobeae and 28 M. tokudae, which were collected from almost all over Japan. All present cases were new host and locality records. The discovery of T. talpae in Japan shows the wide distribution of this species from Japan to Europe. 相似文献
3.
B. Paul Fleming David G. Huffman Timothy H. Bonner Thomas M. Brandt 《Journal of aquatic animal health》2013,25(3):117-124
Abstract We examined the gills of wild fish collected from central Texas for Centrocestus formosanus metacercariae to determine whether this temperature-restricted parasite had invaded the thermally dynamic Guadalupe River via an introduced population in its thermally stable tributary, the Comal River. We collected fish from three sites in the Guadalupe River near its confluence with the Comal River (upstream, at, and downstream) and one site in the Comal River. Centrocestus formosanus infected 14 of the 25 species examined (56.0%) and 171 of the individual fish (27.1%). Several of the infected fish represent new host records for the parasite, and two are listed as species of special concern by the state of Texas. Mean metacercarial intensities varied from 8 to 616 among species, and the highest recorded intensity was greater than 800 in two Guadalupe roundnose minnow Dionda nigrotaeniata. Among the 24 species examined from the Guadalupe River, 11 (45.8%) were infected with C. formosanus. Thorough surveys at the study sites yielded no living specimens of the first obligate intermediate snail host (red-rim melania Melanoides tuberculatus), which must be present to perpetuate the parasite. Thus, the infections were probably due to drifting cercariae that had been shed into the water column upstream of the study area in the Comal River. We therefore investigated spatial patterns in cercarial acquisition using caged fish to determine whether drifting cercariae were present in the water column at the study sites. Of 57 uninfected blacktail shiners Cyprinella venusta exposed to Guadalupe River water downstream from and at the confluence, 52 (91.2%) became infected with C. formosanus metacercariae at a mean rate of 4 metacercariae/d. This finding extends the known geographic range of this invasive exotic parasite and is the first report of the life cycle being advanced in the fish assemblage of a thermally variable temperate stream in the USA. Received October 18, 2010; accepted April 7, 2011 相似文献
4.
Matthee S Lovely C Gaugler A Beeker R Venter HR Horak IG 《Journal of the South African Veterinary Association》2010,81(2):126-128
The objective of this study was to determine the species composition of ixodid ticks infesting domestic dogs in the northwestern region of the Northern Cape Province of South Africa and in Namibia. Ticks were collected from February 2008 to January 2009 from dogs presented for a variety of reasons at a veterinary clinic in the Northern Cape Province and at 3 clinics in Namibia. The ticks collected at each place were pooled separately for each month at each locality. Eleven ixodid tick species were collected from dogs in the Northern Cape Province and new locality records for Haemaphysalis colesbergensis and Ixodes rubicundus, new locality and host records for Hyalomma glabrum, and a new host record for Rhipicephalus neumanni are reported. Six tick species were collected from dogs at the 3 clinics in Namibia. The most numerous species on dogs in both countries was R. sanguineus. The present results increase the total number of ixodid tick species collected from dogs in South Africa from 25 to 28. 相似文献
5.
C. Ensuncho-Hoyos V Rodríguez-Rodríguez A. Pérez-Doria O. Vergara A Calderón-Rangel 《Tropical animal health and production》2017,49(7):1345-1351
The purpose of this study was to determine the epidemiology of leptospirosis in rural areas of Ciénaga de Oro, Córdoba, Colombia, a convenience sampling was carried out on 13 farms. The sample size was 325 reproductive age cows, 11 canine samples, and 20 humans. The samples were subjected to MAT analysis with 11 serogroups of Leptospira interrogans sensu lato. Once the MAT results were received, urine samples were collected from 78 cows, along with 39 water samples, for bacteriological cultures and PCR for the 16S rRNA gene in L. interrogans sensu lato. Positive PCR samples were sequenced to determine the possible genome species. The leptospirosis seroprevalence was 74.5% in the cattle, 70.0% in the dogs, and 45.5% in the humans. Although isolation was not achieved, L. interrogans sensu lato was detected by PCR in three urine samples and in a sample of wastewater. The sequencing confirmed the circulation of pathogenic species. The high prevalence of antibodies for L. interrogans sensu lato and the molecular evidence led to the inference that the rural areas of Ciénaga de Oro are endemic and that cattle can act as renal carriers and contaminate water sources, which increases the risk of contracting leptospirosis. 相似文献
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U. R. Zargar M. Z. Chishti A. R. Yousuf Fayaz Ahmad 《Veterinary research communications》2013,37(3):197-207
In order to assess the species richness and diversity profile of helminth parasite fauna in an endemic fish, an investigation was carried out in two urban and two rural lakes of Kashmir. Overall nine species of helminth parasites were observed in four lakes. Of these three were autogenic and six were allogenic. Heteroxenous parasite species were more in number than monoxenous species. Results showed significant differences in heteroxenous / monoxenous ratio between different lakes. Core species (Prevalence?>?20) were only found in hypertrophic lake (Anchar Lake). Overall, majority of helminth species were either secondary or satellite species. Prevalence of some helminth parasites showed significant differences in different lakes. In addition mean intensity showed significant differences between autogenic and allogenic parasites (P?<?0.05). Principle Component Analysis based on prevalence showed that Anchar Lake was strongly associated with most of helminth parasites. Diversity indices showed significant variation between different lakes. Maximum helminth species per host was in Anchar Lake. Finally we concluded that helminth parasite fauna showed significant differences in species richness and infection indices between different lakes. Diversity profile was higher in Anchar Lake in comparison to other three lakes. The results clearly show that environmental features of lake ecosystems have got an impact on distribution pattern of helminth parasites in S. esocinus. We suggest comparative parasitological study should be taken between different species of fish in order to have a clear picture regarding the species composition of helminth species in this region. Also we need to characterize the species spectrum of parasitic worms in fish of freshwater bodies of this region as well as other similar type of climatic zones because parasite fauna is an integral part of the inventory of biodiversity and as possible regulators of host populations in aquatic ecosystems. 相似文献
8.
An established population of the eastern North American freshwater snail Lymnaea (Pseudosuccinea) columella Say is reported from Middle Creek and Centennial Park, Sydney. This species is an important intermediate host of the liver fluke (Fasciola hepatica Linné) and its introduction and spread in New Zealand has resulted in an increase in the liver fluke problem in New Zealand. 相似文献
9.
Guglielmone AA Estrada-Peña A Mangold AJ Barros-Battesti DM Labruna MB Martins JR Venzal JM Arzua M Keirans JE 《Veterinary parasitology》2003,113(3-4):273-288
DNA sequences of Amblyomma aureolatum (Pallas, 1772) and Amblyomma ovale Koch, 1844 were obtained to determine genetic differences between these tick species. Collections of these species are discussed in relation to distribution and hosts. Seven ticks collections (four from Brazil, one from Argentina, one from Uruguay and one from USA) house a total of 1272 A. aureolatum (224 males, 251 females, 223 nymphs and 574 larvae) and 1164 A. ovale (535 males, 556 females, 66 nymphs and 7 larvae). The length of the sequenced mitochondrial 16S rRNA gene fragment for A. aureolatum was 370bp and for A. ovale was 373bp. The DNA sequence analysis showed a 13.1% difference between the two species. Apart from one male A. ovale found on a toad, all adult ticks were found on mammals. The majority of adult specimens of both tick species were removed from Carnivora (96.1 and 84.3% of A. aureolatum and A. ovale, respectively), especially from dogs (53.1% of A. aureolatum, and 46.4% of A. ovale). Collections on wild Canidae were higher for A. aureolatum (23.3%) than for A. ovale (7.1%). On the other hand, collections of A. ovale adults on wild Felidae were higher (18.3%) than findings of A. aureolatum (9.2%). The contribution of other mammalian orders as hosts for adults of A. aureolatum and A. ovale was irrelevant, with the exception of Perissodactyla because Tapiridae contributed with 13.0% of the total number of A. ovale adults. Adults of both tick species have been found occasionally on domestic hosts (apart of the dog) and humans. Most immature stages of A. aureolatum were found on Passeriformes birds, while rodents and carnivores were the most common hosts for nymphs and larvae of A. ovale. A. aureolatum has been found restricted to the Neotropical region, covering the eastern area of South America from Uruguay to Surinam, including northeastern Argentina, eastern Paraguay, southeastern Brazil and French Guiana. A. ovale showed a distribution that covers the Neotropical region from central-northern Argentina throughout the Neotropics into the Nearctic region of Mexico with a few records from the USA, also with collection sites in Paraguay, Bolivia, most Brazilian states, Peru, Ecuador, French Guiana, Surinam, Guyana, Trinidad & Tobago, Venezuela, Colombia, Panama, Costa Rica, Nicaragua, Belize, Guatemala and several states of Mexico. 相似文献
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The discovery of Trichinella species infecting poikilotherm vertebrates has opened new possibilities in the epidemiology of this parasite group. The aim of the present work was to investigate the infectivity of the two non-encapsulated species of Trichinella infecting both mammals and reptiles, Trichinella papuae and Trichinella zimbabwensis, for equatorial freshwater carnivore fishes. To this end, two species of piranhas, four Serrasalmus nattereri and four Serrasalmus rhombeus, were each inoculated per os with the two species of Trichinella larvae. Six days post infection (p.i.), one fish of each species inoculated with one of the two species of Trichinella was sacrificed. The intestines and celomatic cavities were searched for worms using dissection microscopy, and the presence of muscle larvae was evaluated by artificial digestion. The other 4 inoculated fish were sacrificed 60 days p.i. and similarly searched for the presence of worms. No larva or adult worms were detected in any organ or tissue at 6 or 60 days p.i. The lack of infectivity of T. papuae and T. zimbabwensis for fish suggests that the entozoic habitat of this animal does not represent a suitable environment for these two Trichinella species. More importantly, these data indicate that freshwater fishes, one of the food resources for crocodiles, caimans and alligators, are unlikely to play a role in the epidemiology of the known species of the genus Trichinella. 相似文献
12.
Aiden Biccard 《African Zoology》2016,51(2):99-116
The purpose of this paper is to document recent additions to the South African barnacle (Cirripedia) fauna. New species records were obtained by examining accumulated collections of unidentified material in the Iziko South African Museum, as well as via material collected directly by the authors. Fourteen species, none of which are new to science, are added to the known fauna, raising the total number of barnacle species recorded from South Africa by over 20%, from 69 to 83 species. Ten of the additional species are offshore benthic forms and represent deep-water taxa whose ranges are extended into South African waters. The remaining four are coastal inshore or surface-dwelling species, of which three are considered recent anthropogenic introductions. The large number of additions to the fauna can be attributed to a long absence of taxonomic expertise on this group in the region and consequent accumulation of unidentified samples. A high proportion of the deep-water samples examined contained previously unreported species, suggesting that additional sampling of hard abyssal substrata in the region is certain to yield yet more new cirripede records. 相似文献
13.
Inland waters are highly vulnerable to the introduction and spread of non‐native species, due to heavy human use of aquatic ecosystems and the natural linkages among streams and lakes. This is particularly noticeable in freshwater fish communities. To better evaluate how these communities are affected by non‐native species introductions, we conducted a fine‐scale analysis of the changes in Italian freshwater fish assemblages after species introduction. For this analysis, we collected information on fish species present in 44 basins. The present Italian freshwater fish fauna is composed of 48 native and 41 established introduced species, while a further 15 introduced species have been reported but are not yet considered naturalized. The changes in the fish assemblages mostly took place in the past 2 centuries and have increased recently, with nearly 60% of the species introduced in the past 3 decades. The number of species introduced per basin ranged from 0 to 35 (mean 10.85 ± 7.77 species/basin), and in 10 basins the number of species introduced is now equal to or even higher than the number of native species. In the past, introduced species mainly originated from America, but over the past three decades, an increase of introductions from other parts of Europe and Asia has been recorded. Our results show that basins already rich in native species tend to become even richer as a consequence of the establishment of introduced species. This confirms the trend toward a biotic homogenization of ecosystems even at a local scale, due to an increase in the human‐mediated spread of generalist species. 相似文献
14.
Rubio-Godoy M Paladini G Freeman MA García-Vásquez A Shinn AP 《Veterinary parasitology》2012,186(3-4):289-300
Gyrodactylus salmonis (Yin et Sproston, 1948) isolates collected from feral rainbow trout, Oncorhynchus mykiss (Walbaum) in Veracruz, southeastern Mexico are described. Morphological and molecular variation of these isolates to G. salmonis collected in Canada and the U.S.A. is characterised. Morphologically, the marginal hook sickles of Mexican isolates of G. salmonis closely resemble those of Canadian specimens - their shaft and hook regions align closely with one another; only features of the sickle base and a prominent bridge to the toe permit their separation. The 18S sequence determined from the Mexican specimens was identical to two variable regions of SSU rDNA obtained from a Canadian population of G. salmonis. Internal transcribed spacer (ITS) regions (spanning ITS1, 5.8S and ITS2) of Mexican isolates of G. salmonis are identical to ITS sequences of an American population of G. salmonis and to Gyrodactylus salvelini Kuusela, Zi?tara et Lumme, 2008 from Finland. Analyses of the ribosomal RNA gene of Mexican isolates of G. salmonis show 98-99% similarity to those of Gyrodactylus gobiensis Gl?ser, 1974, Gyrodactylus salaris Malmberg, 1957, and Gyrodactylus rutilensis Gl?ser, 1974. Mexican and American isolates of G. salmonis are 98% identical, as assessed by sequencing the mitochondrial cox1 gene. Oncorhynchus mykiss is one of the most widely-dispersed fish species in the world and has been shown to be an important vector for parasite/disease transmission. Considering that Mexican isolates of G. salmonis were collected well outside the native distribution range of all salmonid fish, we discuss the possibility that the parasites were translocated with their host through the aquacultural trade. In addition, this study includes a morphological review of Gyrodactylus species collected from rainbow trout and from other salmonid fish of the genus Oncorhynchus which occur throughout North America. 相似文献
15.
Recent collections of the Asian fish tapeworm Bothriocephalus acheilognathi in the Rio Grande have raised concern about the potential impacts on Rio Grande endemic and imperiled fishes. The objectives of this study were to determine distribution and definitive hosts of the Asian fish tapeworm within the Rio Grande drainage and to quantify occurrences and abundances. In total, 1,992 fish spanning 11 families were collected and examined for Asian fish tapeworms in the Rio Grande and the Pecos and Devils rivers. The parasite was collected from red shiners Cyprinella lutrensis, Tamaulipas shiners Notropis braytoni, sand shiners N. stramineus, river carpsuckers Carpiodes carpio, plains killifish Fundulus zebrinus, western mosquitofish Gambusia affinis, blue suckers Cycleptus elongatus, blacktail shiners Cyprinella venusta, proserpine shiners Cyprinella proserpina, and Manantial roundnose minnow Dionda argentosa, with the latter four species being new host records. Monthly collections of red shiners from Big Bend National Park exhibited prevalence levels above 15% in January-March and December and below 10% during April-June and October. With over 50% of the Rio Grande icthyofauna in Texas considered imperiled, the occurrence and pathological effects of the Asian fish tapeworm in combination with reduced water quantity and quality and increased habitat fragmentation are of concern for these taxa. 相似文献
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Seven new species of myxosporeans are described from gills of seven freshwater species of fish from Egypt. The annual developmental cycle of the gills involves a period of summer invasion, followed in the autumn by development of cysts (plasmodia + host capsule) and initiation of sporogenesis, completion of sporogenesis in the winter, and the release of spores in the spring. 相似文献
18.
The nematode fauna of 369 spotted mackerel of the species Scomber australasicus, collected off the northeastern Taiwanese coast of the northwestern Pacific, was investigated monthly from April 2004 to March 2005. The following nematode species were recorded: Anisakis simplex complex, Hysterothylacium aduncum, Porrocaecum decipiens and Raphidascaris trichiuri. The seasonal variation in the infection with A. simplex third stage larva (L3) was studied throughout the 12 months. The prevalence of A. simplex L3 recorded for total fish samples was 93.6%, varying between 86.7 and 100%. There was an increase in the abundance of this nematode in spring, with the peak occurring in April. To reveal whether intrinsic factors of the spotted mackerel host contributed to infection with this nematode, fish were grouped according to their body weight, age and gonad development (reported as gonadoosomatic index, GSI), respectively, and infection parameters (i.e., prevalence, abundance and intensity) were analyzed. Results showed that abundance was significantly higher in both larger (>450 g) and older (>3 years old) fish. The gonad development of the host fish was not correlated with the intensity of the larval infection in both female and male fish. Two distinct Anisakis species were identified by PCR-RFLP, namely A. pegreffii and a recombinant genotype of A. pegreffii and A. simplex sensu stricto. These species occurred with frequencies of 97% and 3%, respectively. The usefulness of using parasites as biomarkers for spotted mackerel stock identification around Taiwanese waters was confirmed herein. A second group of 58 spotted mackerel were obtained from the coastal waters off southwestern Taiwan. In addition to the two species, A. pegreffii and the recombinant one, which were found with frequencies of 63% and 9%, respectively, an additional Anisakis species A. typica was identified with a frequency of 28% from these fish. Two spotted mackerel stocks could thus be identified based on their infrastructure of Anisakis species community and their frequency. To the best of our knowledge, this is the first report of stock identification of spotted mackerel using endoparasite biomarkers. 相似文献
19.
Transmission of the microsporidian gill parasite, Loma salmonae 总被引：1，自引：0，他引：1
Becker JA Speare DJ 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2007,8(1):59-68
Since it was first reported in 1987 at a hatchery in British Columbia, Loma salmonae has become increasingly important as an emerging parasite affecting the Canadian salmonid aquaculture industry. L. salmonae causes Microsporidial Gill Disease of Salmon (MGDS) in farmed Pacific salmonids, Oncorhynchus spp., resulting in respiratory distress, secondary infections and high mortality rates. In the last decade, laboratory studies have identified key transmission factors for this disease and described the pathogenesis of MGDS. L. salmonae enters the host via the gut, where it injects sporoplasm into a host cell, which then migrates to the heart for a two-week merogony-like phase, followed by a macrophage-mediated transport of the parasite to the gill, with a final development stage of a spore-laden xenoma within the endothelial and pillar cells. Xenoma rupture triggers a cascade of inflammatory events leading to severe, persistent, and extensive proliferative branchitis. The development of robust and reliable experimental challenge models using several exposure methods in marine and freshwater environments with several fish hosts, is a primary reason for the success of scientific research surrounding L. salmonae. To date, demonstrated factors affecting MGDS transmission include host species, strain and size, the length of contact time between na?ve and infected fish, water temperature and flow rates. 相似文献
20.
Mukaratirwa S Munjere IF Takawira M Chingwena G 《Journal of the South African Veterinary Association》2004,75(4):186-188
Gastrodiscosis outbreaks due to Gastrodiscus aegyptiacus were recorded in horses in the vicinity of Harare, Zimbabwe, in the absence of Bulinus forskalii, B. senegalensis and Cleopatra sp. which are considered to be the only intermediate host snails. This suggested the possibility of other snail species acting as intermediate hosts in the life cycle of the trematode. A study was carried out to determine the susceptibility of 7 freshwater snail species to infection with G. aegyptiacus. First generation (F-1) of 5 freshwater pulmonate snail species, Bulinus tropicus, Bulinus globosus, Biomphalaria pfeifferi, Helisoma dyuri and Physa acuta that were bred in the laboratory, and 2 prosobranch snail species, Melanoides tuberculata and Cleopatra sp. that were collected from the field were used in this study. Data pertaining to mortalities and cercariae shedding were recorded throughout the experimental period. The prosobranch snails, M. tuberculata and Cleopatra sp. were susceptible to G. aegyptiacus with a minimum prepatent period of 45 days and 54 days, respectively. Bulinus tropicus, P. acuta and H. duryi were susceptible as evidenced by the presence of different generations of rediae and mature cercariae on dissection at 59 days post-infection although attempts to induce the snails to shed from 28 days post-infection did not produce cercariae. Bulinus globosus and Bio. pfeifferi were refractory to infection. The results revealed the ability of G. aegyptiacus to infect M. tuberculata, Cleopatara sp., B. tropicus, P. acuta and H. duryi under experimental conditions and this may explain the recorded outbreaks of gastrodiscosis in equine populations in Zimbabwe in the absence of the known intermediate hosts. Bulinus tropicus is considered as the most likely major intermediate host of G. aegyptiacus because of its wide distribution in Zimbabwe and is well adapted to a wide variety of environments. 相似文献