scholarly journals A strong colonizer rules the trematode guild in an intertidal snail host

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Pilar Alda ◽  
Nicolás Bonel ◽  
Néstor J. Cazzaniga ◽  
Sergio R. Martorelli ◽  
Kevin D. Lafferty
Keyword(s):  
Snail Host ◽  
Intertidal Snail

A strong colonizer rules the trematode guild in an intertidal snail host

Ecology ◽  
2019 ◽  
pp. e02696 ◽  
Author(s):  
Pilar Alda ◽  
Nicolás Bonel ◽  
Néstor J. Cazzaniga ◽  
Sergio R. Martorelli ◽  
Kevin D. Lafferty
Keyword(s):  
Snail Host ◽  
Intertidal Snail

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

scholarly journals High parasite diversity in a neglected host: larval trematodes of Bithynia tentaculata in Central Europe

2020 ◽  
Vol 94 ◽  
Author(s):  
J. Schwelm ◽  
O. Kudlai ◽  
N.J. Smit ◽  
C. Selbach ◽  
B. Sures
Keyword(s):  
Central Europe ◽  
Phylogenetic Analyses ◽  
Snail Host ◽  
Morphological Data ◽  
Curonian Lagoon ◽  
Parasite Communities ◽  
Bithynia Tentaculata ◽  
Host Parasite ◽  
Host Families ◽  
High Parasite

Abstract Bithynids snails are a widespread group of molluscs in European freshwater systems. However, not much information is available on trematode communities from molluscs of this family. Here, we investigate the trematode diversity of Bithynia tentaculata, based on molecular and morphological data. A total of 682 snails from the rivers Lippe and Rhine in North Rhine-Westphalia, Germany, and 121 B. tentaculata from Curonian Lagoon, Lithuania were screened for infections with digeneans. In total, B. tentaculata showed a trematode prevalence of 12.9% and 14%, respectively. The phylogenetic analyses based on 55 novel sequences for 36 isolates demonstrated a high diversity of digeneans. Analyses of the molecular and morphological data revealed a species-rich trematode fauna, comprising 20 species, belonging to ten families. Interestingly, the larval trematode community of B. tentaculata shows little overlap with the well-studied trematode fauna of lymnaeids and planorbids, and some of the detected species (Echinochasmus beleocephalus and E. coaxatus) constitute first records for B. tentaculata in Central Europe. Our study revealed an abundant, diverse and distinct trematode fauna in B. tentaculata, which highlights the need for further research on this so far understudied host–parasite system. Therefore, we might currently be underestimating the ecological roles of several parasite communities of non-pulmonate snail host families in European fresh waters.

Studies of the relationships between Schistosoma nasale and S. spindale and their snail host Indoplanorbis exustus

1991 ◽  
Vol 65 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. de Bont ◽  
J. Vercruysse ◽  
D. van Aken ◽  
V. R. Southgate ◽  
D. Rollinson
Keyword(s):  
Sri Lanka ◽  
Intermediate Host ◽  
Snail Host ◽  
Infection Rates ◽  
Death Rates ◽  
Cercarial Production ◽  
Indoplanorbis Exustus ◽  
Level 1 ◽  
Host Parasite ◽  
Opposite Tendency

ABSTRACTInfectivity and cercarial production of Indoplanorbis exustus related to variation of miracidial dose (1, 4, 10 or 20) with Schistosoma nasale and S. spindale from Sri Lanka were studied. The intermediate host-parasite relationships of the two schistosome species showed marked differences under the conditions of observation recorded in this study. Prepatent death rates (PDR) were on average higher for S. spindale (30%) than for S. nasale (10%). The size of the miracidial dose to which snails had been exposed had no effect on PDR. The infection rates (IR) were on average higher for S. nasale (41%) compared with S. spindale (27%). Highest IR occurred after exposure to 4 miracidia in S. nasale infections (79%) and after exposure to 10 miracidia in S. spindale infections (6O%). The highest daily average cercarial production per snail was recorded for S. nasale at a level of 4 miracidia (1311), and for S. spindale at a level of 10 miracidia (1615). At low level (1 or 4 miracidia) of exposure, I. exustus showed a better compatibility with S. nasale than with S. spindale. An opposite tendency was observed at higher levels (10 or 20 miracidia) of exposure. Unsuccessful infections of Lymnaea luteola with either S. nasale or S. spindale indicate that this species is not involved in transmission.

Energy constraint exerted by the parasite Schistosoma mansoni on the locomotion of its snail host, Biomphalaria glabrata

1996 ◽  
Vol 74 (4) ◽  
pp. 594-598 ◽  
Author(s):  
Claudia Gérard
Keyword(s):  
Resource Allocation ◽  
Schistosoma Mansoni ◽  
Biomphalaria Glabrata ◽  
Snail Host ◽  
Locomotory Activity ◽  
Patent Period ◽  
Energy Constraint

The consequences of the constraint caused by the parasite Schistosoma mansoni on the locomotory activity of its snail host, Biomphalaria glabrata, were studied during the patent period. Rates of locomotion were determined 6 times per 24-h period for juvenile and adult snails with single-miracidium infections, then compared with those of healthy snails of the same age. The locomotory activity of infected snails was the same during the day and at night, whereas control snails moved less at night than during the day. The locomotion of snails infected when immature was similar to that of the controls during the day and superior at night. The locomotion of snails infected when mature decreased regularly during patency and clearly decreased in comparison with that of healthy snails. The results are interpreted in terms of energy constraint on the mode of resource allocation of the host due to the parasite.

scholarly journals Structural and Population Polymorphism of RT-Like Sequences in Avian SchistosomesTrichobilharzia szidati(Platyhelminthes: Digenea: Schistosomatidae)

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
S. K. Semyenova ◽  
G. G. Chrisanfova ◽  
A. S. Guliaev ◽  
A. P. Yesakova ◽  
A. P. Ryskov
Keyword(s):  
Host Specificity ◽  
Lymnaea Stagnalis ◽  
Strong Association ◽  
Snail Host ◽  
New Members ◽  
East Europe ◽  
Causative Agents ◽  
History Of ◽  
Avian Schistosomes ◽  
Parasite Evolution

Recently we developed the genus-specific markers of the avian schistosomes of the genusTrichobilharzia, the causative agents of human cercarial dermatitis. The 7 novel genome sequences ofT. franki, T. regenti, andT. szidatirevealed similarity with genome repeat region of African schistosomeSchistosoma mansoni. In the present work we analyzed the 37 newT. szidatisequences to study intragenome variability and host specificity for the parasite from three localities of East Europe. DNAs were isolated from cercariae or single sporocysts obtained from 6 lymnaeid snailsLymnaea stagnalisandL. palustrisfrom Belarus and Russia. All sequences formed three diverged groups, one of which consists of the sequences with multiple deletions; other groups involved two paralogous copies with stop codons and frameshift mutations. Strong association between geographical distribution and snail host specificity cannot be established. All studied sequences have homology with the reverse transcriptase domain (RT) of Penelope-like elements (PLE) ofS. mansoniandS. japonicumand new members of RT family were identified. We proposed that three diverged groups RT sequences ofT. szidatiare results of duplication or transposition of PLE during parasite evolution. Implications of the retroelement dynamics in the life history of avian schistosomes are discussed.

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