scholarly journals Susceptibility of 7 freshwater gastropod species in Zimbabwe to infection with Gastrodiscus aegyptiacus (Cobbold, 1876) Looss, 1896 : short communication

2004 ◽  
Vol 75 (4) ◽  
Author(s):  
S. Mukaratirwa ◽  
I.F. Munjere ◽  
M. Takawira ◽  
G. Chingwena
Keyword(s):  
Intermediate Host ◽  
Post Infection ◽  
Experimental Period ◽  
Freshwater Snail ◽  
Wide Distribution ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Biomphalaria Pfeifferi ◽  
Experimental Conditions ◽  
Bulinus Globosus

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.

Effects of land use on intermediate snail host fauna, abundance, distribution and cercariae infection rate in Omo-Gibe river basin, Ethiopia

2020 ◽  
Author(s):  
Ketema Deribew ◽  
Etana Jaleta ◽  
Belayhun Mandefro ◽  
Zeleke Mekonnen ◽  
Delenasaw Yewhalaw ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Fresh Water ◽  
River Basin ◽  
Anthropogenic Activities ◽  
Freshwater Snail ◽  
Snail Host ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Biomphalaria Pfeifferi

Abstract Background: Land use and land cover change significantly affects biodiversity, abundance and distribution of intermediate snail host fauna. In Omo-Gibe river basin the extent of land-use change is high due to anthropogenic activities leading to habitat change of freshwater snail intermediate hosts. Most intermediate snail hosts of human Schistosome parasites belong to two genera, Biomphalaria and Bulinus. In Addition, Lymnea spp. is another important host of Fasciola which causes fasciolasis in domestic animals and human. This study aims to assess the effects of land-use on the distribution and abundance of freshwater snail intermediate hosts and cercariae infection rates of fresh water intermediate snail hosts in Omo-Gibe River basin, Ethiopia.Methods: This study was conducted in Omo-Gibe river basin in 130 sampling sites which include rivers, lakes, dams, stream, wetlands and irrigation ditches. At each site data on land use, anthropogenic activities, freshwater snail abundance and species diversity, and water samples were collected. Snails were collected from each sampling sites using a scoop (20cm x 30cm) with a mesh size of 300µm. Snails were sorted by genus on Enamel pan using forceps and preserved in labeled vials containing 75% ethanol. Live snails collected from the same habitat were sorted carefully and put in clean plastic buckets half filled with water. Afterwards, snails were provided with fresh lettuce leaves and maintained in the laboratory. Snails were then identified morphologically to family, genus and to species level. Each snail was examined for cercaria shedding by placing in a petri dish containing water and exposed to the sun for 2 hours. Cercariae were morphologically identified by microscopy. ArcGIS software of version 10.3.1 was used to map snail distribution and data were analysed using SPSS version-20.Results: The results obtained in this study shows clearly that land use change affect the distribution and abundance of fresh water snails in Omo-Gibe river basin. Fresh water snails were more abundant in farmland and settlement areas. Of the total 2,559 freshwater snails collected from 130 surveyed sites in Omo-Gibe river basin, 1749 (68.34%) belongs to medically important snail species. Biomphalaria spp.914 (35.7%),, Lymnea spp.439 (17.1%),, Physa spp. 343(13.4%) and Bulinus spp 53 (2%)). Sphaeriidae group accounted for 810 (31.6%) of the collected specimens. Biomphalaria pfeifferi was the predominant species of the total snail sampled from lakes, wetlands, rivers and irrigation ditches. Biomphalaria pfeifferi was the most infected snail species by different cercariae. Bulinus globosus and L.natalensis were infected by more than one and same type of cercariae. However, none of B. sudanica and P. acuta specimens was infected by trematode.Conclusions: The results of this study revealed that land use change altered the abundance, distribution and diversity of medically important fresh water snails in the study area. In general medically important freshwater snails which include: Biomphalaria spp, Bulinus spp and Lymnaea spp were collected from lakes, rivers, wetlands, irrigation ditches.. The medically important snail species found infected by cercaria are L. natalensis, B. pfeifferi and B. globosus. Biomphalaria pfefferi was the predominant species and highly infected by cercariae. Higher infection rate was observed in snails collected in Farmland (16.59%) and Grassland (36.6%).

scholarly journals Distribution and habitats of Bulinus tropicus, snail intermediate host of the conical fluke Calicophoron microbothrium, in South Africa

2002 ◽  
Vol 21 (4) ◽  
pp. 114-120
Author(s):  
K. N. De Kock ◽  
C. T. Wolmarans ◽  
M. Bornman ◽  
D. C. Maree
Keyword(s):  
South Africa ◽  
Intermediate Host ◽  
Geographical Distribution ◽  
Freshwater Snail ◽  
Wide Distribution ◽  
Limiting Factor ◽  
Snail Species ◽  
Rural Settlements ◽  
Economic Implications ◽  
Snail Intermediate Host

This paper focuses on the geographical distribution and the habitats of Bulinus tropicus, the snail intermediate host of the conical fluke, Calicophoron microbothrium. Bulinus tropicus is the freshwater snail species with the most extensive geographical distribution, as reflected by the collection sites of the 7 992 samples currently on record in the database of the National Freshwater Snail Collection (NFSC) of South Africa. The presence of this species was noted by collectors in a total of 14 different types of waterbodies, however, the largest number of samples was collected in dams and brooks and in habitats of which the water was described as standing, clear and fresh. The effect size was calculated for each variable separately to determine its importance in governing the distribution of this species. The data in the database were further processed and adapted to construct an integrated decision tree. This is a statistical model allowing the selection of those variables which can maximally discriminate between the frequency of occurrence of a given species and all other species in the database under specific conditions. The success of B. tropicus, as reflected by its extensive geographical distribution, can most probably be ascribed to the circumstance that population dynamic studies by various authors have shown, without any doubt, that it is highly r-selected and that it additionally has the ability to survive conditions of drought for elatively long periods. It does however, appear as if its limited tolerance to water with a relatively low conductivity could possibly be a limiting factor for its colonisation of specific areas in South Africa. As intermediate host of C. microbothrium which causes paramphistomosis in domestic stock and sometimes can lead to great losses, the wide distribution of B. tropicus has economic implications, especially for residents of informal, rural settlements whose livestock traditionally forms an integral part of their daily existence.

scholarly journals Are Freshwater Snails, Melanoides sp. and Invasive Tarebia granifera (Gastropoda: Thiaridae) Suitable Intermediate Hosts for Calicophoron microbothrium (Trematoda: Paramphistomoidea)? An Experimental Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Mokgadi P. Malatji ◽  
Nkululeko Myende ◽  
Samson Mukaratirwa
Keyword(s):  
South Africa ◽  
Soft Tissues ◽  
Morphological Characters ◽  
Wide Distribution ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Experimental Conditions ◽  
Mpumalanga Province ◽  
Filial Generation ◽  
Tarebia Granifera

Prosobranch snails and adult Paramphistomoidea flukes were collected from water bodies and cattle abattoir located in Mpumalanga province of South Africa, respectively. The snails were identified based on morphological characters as well as the ITS-2 and 16S markers as Melanoides sp. and Tarebia granifera, respectively, and the Paramphistomoidea flukes were identified as Calicophoron microbothrium using the ITS-1/5.8S/ITS-2 marker. After confirming identification, the snails were bred to first filial generation (F1) under laboratory conditions. Ninety snails were randomly selected from the laboratory-bred F1 snails and 25 Melanoides sp. and 20 T. granifera were exposed to C. microbothrium miracidia, and the same numbers were maintained as non-exposed controls. Results showed that C. microbothrium successfully established in Melanoides sp. and produced cercariae, and the prepatent period recorded was 21 days. Three snails shed cercariae at day 21 postexposure (PE), and rediae and free cercariae were detected in the soft tissues of one snail on dissection at day 44 PE. The same fluke did not establish in T. granifera. Melanoides sp. started producing offspring at day 7 PE, and T. granifera at day 14 PE. In conclusion, our results showed that Melanoides sp. used in this study is a suitable intermediate host for C. microbothrium under experimental conditions, and given the wide distribution of this snail species, it is important to determine its role in the natural transmission of other Calicophoron species that have been reported in South Africa.

scholarly journals Survey of Fresh Water Snails in Vandeikya Local Government Area, Benue State Nigeria

2019 ◽  
pp. 1-8
Author(s):  
T. S. Atsuwe ◽  
J. I. Chikwendu ◽  
V. U. Obisike
Keyword(s):  
Local Government ◽  
Fresh Water ◽  
Freshwater Snail ◽  
Local Government Area ◽  
Freshwater Snails ◽  
Snail Species ◽  
Biomphalaria Pfeifferi ◽  
Factors Affecting ◽  
Water Ph ◽  
Bulinus Globosus

A survey was carried out in Vandeikya Local Government Area of Benue State, Nigeria from April-July 2017 to determine availability of freshwater snails of and their preferred habitats. A total of 289 fresh water snails of four different genera were collected across 27 streams in the 7 districts in Vandeikya LGA. Water pH, water temperature and water velocity were also measured. Lenistislibycuswas found to be the most abundant freshwater snail species accounting for 40.83% of the total freshwater snails. Melanoidestuberculata was the second most abundant accounting for 29.411% of the total snails population sampled, Biomphalaria pfeifferi accounted for 17.99% while Bulinus globosus was significantly lower in abundance than the other snails, accounting for only 11.77%. By location, Mbaduku district had highest abundance of snails 84 (29.1%). The effect of the nature of the substratum on the availability of freshwater snails revealed that habitats with rocky substratum favoured the presence of snails accounting for 181(62.7%) freshwater snail collected.Our understanding of factors affecting the availability and abundance of freshwater snails in nature can prove useful in snail control which is integral for the control of the diseases for which they serve as intermediate host.

The influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum

1999 ◽  
Vol 73 (2) ◽  
pp. 143-145 ◽  
Author(s):  
A.M. McCarthy
Keyword(s):  
Intermediate Host ◽  
Definitive Host ◽  
Host Species ◽  
Post Infection ◽  
Rana Temporaria ◽  
Biomphalaria Glabrata ◽  
Reproductive Status ◽  
Intermediate Hosts ◽  
Potential Influence ◽  
Second Intermediate Host

The potential influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum to the definitive host Anas platyrhynchos was examined experimentally. Echinoparyphium recurvatum metacercarial cysts were obtained from the following experimentally infected second intermediate hosts 14 days post expsoure to cercariae: Lymnaea peregra; Physa fontinalis; L. stagnalis;Planorbis planorbis; Biomphalaria glabrata; tadpoles of the amphibian Rana temporaria. Metacercarial cysts from each of these hosts were fed, in doses of 50 cysts per individual, to separate groups composed of between four and eight, 3-day-old A. platyrhynchos ducklings. All A. platyrhynchos were necropsied 15 days post-infection and the number, size, and reproductive status of E. recurvatum worms in the intestine was recorded. Analyses of variance on the number (transformed log (x + 1)) and size of worms revealed no significant differences in worms originating from metacercariae formed in the different second intermediate hosts (worm number P > 0.05, and worm size P > 0.05). All worms recovered were found to be gravid. It is therefore concluded that the species of second intermediate host utilized does not influence the infectivity of the metacercarial cyst of E. recurvatum, nor the subsequent establishment and reproductive status of the parasite in A. platyrhynchos.

Larval development of ovine Neostrongylus linearis in four experimentally infected mollusc species

1994 ◽  
Vol 68 (3) ◽  
pp. 207-210 ◽  
Author(s):  
M.Y. Manga-González ◽  
M.P. Morrondo-Pelayo
Keyword(s):  
Post Infection ◽  
The Other ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Cepaea Nemoralis ◽  
In Series ◽  
Mollusc Species ◽  
Higher Temperature ◽  
The One ◽  
First Time

AbstractDevelopment of Neostrongylus linearis larvae was studied in the snail intermediate hosts Oestophora (Oestophora) barbula, Oestophorella buvinieri, Cepaea nemoralis and Helix (Cryptomphalus) aspersa. The molluscs of each species, all adults, were divided into groups of 40 for infection purposes. The infection doses for the first two snail species were 90 and 50 first stage larvae (L1) of N. linearis, respectively. For C. nemoralis two batches were tested: one with 200 L1 kept at 19°C and the other with 250 L1 at a temperature of 21°C. The same was done with Helix (C.) aspersa with 200 L1 at a temperature of 21°C, on the one hand and 300 L1 at 24°C on the other. One or two molluscs of each species were killed in series from the 6th day post-infection (p.i.) until the 44th. Percentage values for total larvae (1, 2 and 3) and L3 were higher with the lower dose for C. nemoralis, whilst the same was true with the higher dose in Helix (C.) aspersa. In both cases, the higher temperature appeared to contribute to cycle acceleration. Using one way analysis of variance, statistically significant differences were detected between the species of molluscs tested concerning percentages of L1 which penetrated, total larvae and L3. According to our results, the decreasing order of susceptibility of these species of molluscs as experimental intermediate hosts of N. linearis is: O. buvinieri, Oestophora (O.) barbula, C. nemoralis and Helix (C.) aspersa. It is the first time that Oestophora (O.) barbula and Oestophorella buvinieri have been named as experimental intermediate hosts of N. linearis.

scholarly journals MALDI-TOF mass spectrometry for the identification of freshwater snails from Senegal, including intermediate hosts of schistosomes

2021 ◽  
Vol 15 (9) ◽  
pp. e0009725
Author(s):  
Fatima Zohra Hamlili ◽  
Fatou Thiam ◽  
Maureen Laroche ◽  
Adama Zan Diarra ◽  
Souleymane Doucouré ◽  
...  
Keyword(s):  
Neglected Diseases ◽  
Freshwater Snails ◽  
Snail Species ◽  
Correct Identification ◽  
Intermediate Hosts ◽  
Biomphalaria Pfeifferi ◽  
Bulinus Truncatus ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Freshwater snails of the genera Biomphalaria, Bulinus, and Oncomelania are intermediate hosts of schistosomes that cause human schistosomiasis, one of the most significant infectious neglected diseases in the world. Identification of freshwater snails is usually based on morphology and, potentially, DNA-based methods, but these have many drawbacks that hamper their use. MALDI-TOF MS has revolutionised clinical microbiology and has emerged in the medical entomology field. This study aims to evaluate MALDI-TOF MS profiling for the identification of both frozen and ethanol-stored snail species using protein extracts from different body parts. A total of 530 field specimens belonging to nine species (Biomphalaria pfeifferi, Bulinus forskalii, Bulinus senegalensis, Bulinus truncatus, Bulinus globosus, Bellamya unicolor, Cleopatra bulimoides, Lymnaea natalensis, Melanoides tuberculata) and 89 laboratory-reared specimens, including three species (Bi. pfeifferi, Bu. forskalii, Bu. truncatus) were used for this study. For frozen snails, the feet of 127 field and 74 laboratory-reared specimens were used to validate the optimised MALDI-TOF MS protocol. The spectral analysis yielded intra-species reproducibility and inter-species specificity which resulted in the correct identification of all the specimens in blind queries, with log-score values greater than 1.7. In a second step, we demonstrated that MALDI-TOF MS could also be used to identify ethanol-stored snails using proteins extracted from the foot using a specific database including a large number of ethanol preserved specimens. This study shows for the first time that MALDI-TOF MS is a reliable tool for the rapid identification of frozen and ethanol-stored freshwater snails without any malacological expertise.

scholarly journals Do self-fertilization and genetic drift promote a very low genetic variability in the allotetraploid Bulinus truncatus (Gastropoda: Planorbidae) populations?

1993 ◽  
Vol 62 (2) ◽  
pp. 89-100 ◽  
Author(s):  
Flobert Njiokou ◽  
Christian Bellec ◽  
Patrick Berrebi ◽  
Bernard Delay ◽  
Philippe Jarne
Keyword(s):  
Genetic Drift ◽  
Freshwater Snail ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Bulinus Truncatus ◽  
Genetic Structure Of Populations ◽  
Self Fertilization ◽  
High Gene ◽  
Almost All

SummaryBulinus truncatus, one of the intermediate hosts of the genus Schistosoma is an hermaphrodite freshwater snail species occupying a variety of environments over almost all Africa. These environments are subjected to large variations in water availability. B. truncatus is allotetraploid and its populations exhibit various frequencies of aphallic individuals (unable to reproduce as male). Both traits probably favour a reproduction by self-fertilization. Here we investigate the genetic structure of populations of B. truncatus of Niger and Ivory Coast using protein electrophoresis to analyse the influence of the environment and of both the last traits. To obtain an estimate of the true heterozygosity in this allotetraploid species, we analyse independently the two diploid loci at each tetraploid locus. Our study indicates (i) an extremely low intrapopulation polymorphism with most alleles fixed and the total absence of heterozygotes and (ii) low differentiation between populations. These results indicate high gene flow between populations. However, the existence of private alleles sometimes at high frequency, the low polymorphism and the lack of heterozygotes point to the role of both genetic drift and self-fertilization, the second amplifying the genetic consequences of the first.

scholarly journals Annotated and Updated Checklist of Land and Freshwater Molluscs from Asturias (Northern Spain) with Emphasis on Parasite Transmitters and Exotic Species

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 415
Author(s):  
Omar Sánchez ◽  
Jairo Robla ◽  
Andrés Arias
Keyword(s):  
Exotic Species ◽  
Animal Health ◽  
Freshwater Snail ◽  
Parasitic Infections ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Northern Spain ◽  
Current Increase ◽  
Freshwater Molluscs ◽  
Local Diversity

Land and freshwater molluscs are the most abundant non-arthropod invertebrates from inland habitats worldwide, playing important ecological roles and some being important pests in agriculture. However, despite their ecological, and even economic and sanitary importance, their local diversity in many European regions is not perfectly understood, with a particularly notableknowledge gap in the northern Iberian malacofauna. This work aims at providing a revised checklist of continental gastropods and bivalves from the Asturias (northern Spain), based on the examination of newly collected and deposited material and on the critical analysis of published and gray literature. A total of 165 molluscan species are recognized. Ten species constitute new records from Asturias and seven from northern Iberian Peninsula. Seventeen species are introduced or invasive, evidencing the current increase of the bioinvasion rate in continental molluscs. Furthermore, all these exotic species are parasite transmitters or trematode intermediate hosts, and thus represent a potential bio-sanitary risk for human and other animal health. The provided data strongly suggest that the increase of invasive freshwater snail species can lead to an increase in parasitic infections, and this is a crucial point that transcends the merely scientific to the political-social sphere.

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