Forgetting may allow an animal to react more appropriately to current conditions, rather than continuing to exhibit a previously learned, possibly maladaptive behaviour based on previous experience. One theory is that forgetting is an active process, whereby the previously learnt response is replaced by new learning that interferes with the older memory. Hence, we hypothesized that an appropria...

The 18S rDNA sequences of the six most common European Lymnaeidae species (Mollusca:Gastropoda:Basommatophora) have been obtained by direct PCR cycle sequencing and silver staining methods. The sequence alignment and secondary structures of the 18S rRNA gene of Lymnaea stagnalis, L. auricularia, L. peregra, L. palustris, L. glabra, and L. truncatula are analyzed. This gene proves to be a good m...

Environmental calcium is a major factor affecting the distribution of freshwater gastropods. Whilst the effects on growth and morphology are fairly well understood, little is known about how calcium availability affects other aspects of gastropod biology. Lymnaea stagnalis (L.) is considered a calciphile and exhibits reduced growth and survival in environments containing less than 20 mg l(-1) C...

Spilanthus acemella Murr. also known as toothache plant is investigated for its preliminary phytochemical analysis and molluscicidal activity. The water extract found maximum extractive value (3.730%) than other solvents used. All the tested metabolites were qualitatively present in ethanolic extract and aqueous extract. Different concentrations of plant parts (root stem, leaf) were used for mo...

Evolutionary Aspects of Neuropeptides and their Genes Structure and evolution of insulin and insulin-like growth factors in chordates p. 15 Relationships among the FMRFamide-like peptides p. 25 Molecular evolution of neurohypophysial hormone precursors p. 39 A vasopressin-related peptide in the mollusc Lymnaea stagnalis: Peptide structure, prohormone organization, evolutionary and functional as...

The pond snail Lymnaea stagnalis is an intermediate vector for the liver fluke Fasciola hepatica, a common parasite of ruminants and humans. Yet, despite being a disease of medical and economic importance, as well as a potentially useful comparative tool, the genetics of the relationship between Lymnaea and Fasciola has barely been investigated. As a complement to forthcomingF. hepatica express...

The paper presents a study leading to a new acute toxicity test on embryonic and juvenile organisms of the great pond snail (Lymnaea stagnalis Linnaeus). Sulfuric acid, nitric acid, and ammonium hydroxide were used as waterborne toxicants in laboratory experiments. The exposure time was 24 h. Tests were conducted in 5–10 replications for each toxicant. The toxicity of the substances was classif...