Results 191 to 200 of about 8,626 (212)

Chromosomes of Gyraulus circumstratius, a Freshwater Snail

Nature, 1960
POLYPLOIDY is relatively scarce in the animal kingdom, and is apparently almost entirely confined to those species in which reproduction is partheno-genetic, hermaphroditic or clonal1. Such animals usually do not have a heterogametous sex-determining mechanism to be disturbed by polyploidy.
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Freshwater snails in brackish water

1929
(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
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Fixed phagocytes in the freshwater snail Lymnaea stagnalis

Cell and Tissue Research, 1979
Morphological and histochemical examination of the blood and connective tissue of the freshwater snail Lymnaea stagnalis injected with various types of foreign particulate materials has shown the existence of free as well as fixed phagocytic cells. The morphology of the fixed phagocytes is described, and the phagocytic system of the snail is compared ...
W. P. W. van der Knaap, F. G. M. Kroese, Taede Sminia   +2 more
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On the underwater weights of freshwater snails

Zeitschrift f�r Vergleichende Physiologie, 1963
1. Under laboratory conditions, the mantle cavities of Lymnaea stagnalis and Planorbarius corneus immediately after ventilation at the surface, contain enough air to make the animals buoyant. 2. Both species lose this buoyancy over the first three hours of submersion by a process reducing the gas volume. 3. The gas is used as
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Bioconcentration ratio of diazinon by freshwater fish and snail [PDF]

Bulletin of Environmental Contamination and Toxicology, 1978
The bioconcentration ratios of diazinon from water by freshwater fishes were generally larger than that of crayfish and snails. Among fishes, the bioconcentration ratio of diazinon by topmouth gudgeon was the highest value, 152 being average. However, elimination of diazinon from fish body was linearly rapid.
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The Inheritance of Albinism in a Freshwater Snail, Physa heterostropha

Journal of Heredity, 1992
Complementation tests revealed that albinism in four laboratory strains of Physa (Physella) heterostropha pomilia resulted from two recessive, nonallelic genes. F2 dihybrid progeny displayed the 9:7 ratio classically associated with reciprocal recessive epistasis between unlinked loci.
Robert T. Dillon, Amy R. Wethington
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Habituation in a freshwater snail (Limnaea stagnalis)

Animal Behaviour, 1971
Abstract Withdrawal responses were elicited by mechanical or visual stimuli and recorded both automatically and by observation. With stimulus repetition both response amplitude and frequency decline but the latency remains about the same: these effects are short lived.
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Checklist of the freshwater snails (Mollusca: Gastropoda) of Mongolia

Zootaxa, 2017
The paper is the first illustrated check-list of the freshwater Gastropoda of the state of Mongolia. The authors examined their own samplings made in 2009–2012 as well as collections of other explorers and zoological museums (mostly those of Russia). In total, 35 nominal species of four families (Valvatidae, Lymnaeidae, Physidae, and Planorbidae) have ...
Vadim V. Marinskiy, Maxim V. Vinarski, Dmitry M. Palatov   +2 more
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The transfer of lead by freshwater snails in Ullswater, Cumbria

Environmental Pollution Series A, Ecological and Biological, 1984
Abstract The cycling of lead by freshwater snails from primary producers and detritus, through the snails and snail-predators, and back into the sediments was investigated. The concentrations of lead in snails collected from Ullswater, Cumbria, correlated with the degree of contamination at particular sites. When snails were fed on lead-enriched food
Mark Everard, Patrick Denny
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Short communication. Pipelines as a refuge for freshwater snails

Regulated Rivers: Research & Management, 1993
AbstractIn the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences.
Keith F. Walker, Fran Sheldon
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