Search results for "snail"

Trematode cercariae as prey for zooplankton: effect on fitness traits of predators.

2019

AbstractRemoval of parasite free-living stages by predators has previously been suggested an important factor controlling parasite transmission in aquatic habitats. Experimental studies of zooplankton predation on macroparasite larvae are, however, scarce. We tested whether trematode cercariae, which are often numerous in shallow waters, are suitable prey for syntopic zooplankters. Feeding rates and survival of freshwater cyclopoids (Megacyclops viridis, Macrocyclops distinctus), calanoids (Arctodiaptomus paulseni), cladocerans (Sida crystallina) and rotifers Asplanchna spp., fed with cercariae of Diplostomum pseudospathaceum, a common fish trematode, were studied. In additional long-term e…

Furcocercous cercariae (Trematoda) from freshwater snails in Central Finland

2007

AbstractA total of eight species of furcocercous cercariae of four families (Strigeidae, Diplostomidae, Schistosomatidae and Sanguinicolidae), were found in 2005 in Lake Konnevesi in Central Finland in four snail species (Valvata macrostoma, Lymnaea stagnalis, Bathyomphalus contortus and Planorbarius corneus). Australapatemon burti (Miller, 1923), Australapatemon sp., Cotylurus brevis Dubois et Rausch, 1950, Cercaria spinulosa Ginetsinskaya, 1959 and Sanguinicola sp. are new species records for Finland. Ichthyocotylurus variegatus (Creplin, 1825) and Bilharziella polonica (Kowalewski, 1895) were first recorded as cercariae in Finland. The most common cercariae were A. burti (prevalence 13.3…

2019

Global changes promote the spread of infectious diseases worldwide. In this context, tropical urogenital schistosomiasis is now permanently established in Corsica since its first emergence in 2013. The local persistence of the tropical pathogens (schistosomes) responsible for urogenital schistosomiasis at such latitudes might be explained by (i) the presence of its intermediate host, the snail Bulinus truncatus, (ii) the recurrent local reseeding of schistosomes by their vertebrate hosts (either human or animal) every summer, and/or (iii) the maintenance and survival of schistosomes within their snail hosts over winter. In this study we conducted an ecological experiment to assess the abili…

The transcription factor ZEB1 (deltaEF1) promotes tumour cell dedifferentiation by repressing master regulators of epithelial polarity.

2007

Epithelial to mesenchymal transition (EMT) is implicated in the progression of primary tumours towards metastasis and is likely caused by a pathological activation of transcription factors regulating EMT in embryonic development. To analyse EMT-causing pathways in tumouri-genesis, we identified transcriptional targets of the E-cadherin repressor ZEB1 in invasive human cancer cells. We show that ZEB1 repressed multiple key determinants of epithelial differentiation and cell–cell adhesion, including the cell polarity genes Crumbs3, HUGL2 and Pals1-associated tight junction protein. ZEB1 associated with their endogenous promoters in vivo, and strongly repressed promotor activities in reporter …

CAN HELICICULTURE ACT AS A TOOL FOR EDIBLE LAND SNAILS’ NATURAL POPULATIONS’ MANAGEMENT IN ROMANIA?

2013

ABSTRACT Edible land snails are intensively exploited and the management of natural populations is a complex issue due the variety of factors involved. Two species of the genus Helix are present in our country, Helix pomatia and Helix lucorum, both of them collected since 1956. Although current legislation regulates the exploited amount and the dimension of collected snails, the exploitable amount is not assessed using appropriate ecological studies. The farming of edible snails has evolved in Romania especially during the period 2004-2008, the first farms being financed by the SAPARD Project. The inappropriate documentation on the matter of snail farming had lead to a quick failure of this…

Antigens of <i>Euparipha pisana</i> (Snail)

1988

The data obtained in this study suggest that eating <i>Euparipha pisana</i> (snail), a common food in Mediterranean countries, could give serious allergic reaction such as asthma. We describe here the identification and partial characterization of allergenic molecules form this new source. An aqueous extract of snail was obtained by homogenization in distilled water, centrifugation, dialysis and defatting with ethyl ether. Skin prick test (SPT) performed with the snail extract on 70 subjects allergic to the more common allergens of the Mediterranean area gave a SPT positivity in 61% of the subjects tested, with a mean value of histamine-equivalent prick (HEP) equal to 0.81 ± 0.2…

Schistosomes in the north: a unique finding from a prosobranch snail using molecular tools.

2009

article i nfo Samples of schistosome cercariae from three different snail species (Lymnaea stagnalis, Radix auricularia and Valvata (Tropidina) macrostoma) collected from lakes in Central Finland were analyzed using molecular techniques. Based on sequences of ITS region of rDNA, the parasite isolates from L. stagnalis and R. auricularia belong to Trichobilharzia szidati and T. franki, respectively. This confirms a wide distribution of these two species in Europe. On the other hand, the isolates from V. macrostoma represent a unique finding — they belong to yet unknown schistosome species falling into the bird schistosome clade. Therefore, identification of natural final hosts and morphologi…

QUALITATIVE AND QUANTITATIVE BEHAVIORAL TRAITS IN A COMMUNITY OF FURCOCERCARIAE TREMATODES: TOOLS FOR SPECIES SEPARATION?

2008

Many trematode cercariae show distinct behavioral features, which have commonly been used in species identification in combination with morphological characteristics. However, information regarding cercariae behavior has often not been quantified in detail, or it is scattered in the literature, which is why the appropriate level of precision in behavioral identity, particularly in groups of cercariae species showing considerable morphological overlap, has not been properly established. In this study, we investigated one such group, the furcocercariae trematodes, by studying their behavior in a community consisting of 8 species (Diplostomum pseudospathaceum, Ichthyocotylurus variegatus, Coty…

Biogenic habitat shifts under long-term ocean acidification show nonlinear community responses and unbalanced functions of associated invertebrates

2019

Este artículo contiene 8 páginas, 4 figuras.

Insights into the relationships of Palearctic and Nearctic lymnaeids (Mollusca : Gastropoda) by rDNA ITS-2 sequencing and phylogeny of stagnicoline i…

2003

Fascioliasis by Fasciola hepatica is the vector-borne disease presenting the widest latitudinal, longitudinal and altitudinal distribution known. F. hepatica shows a great adaptation power to new environmental conditions which is the consequence of its own capacities together with the adaptation and colonization abilities of its specific vector hosts, freshwater snails of the family Lymnaeidae. Several lymnaeid species only considered as secondary contributors to the liver fluke transmission have, however, played a very important role in the geographic expansion of this disease. Many of them belong to the so-called "stagnicoline" type group. Stagnicolines have, therefore, a very important a…