Results 201 to 210 of about 31,696 (245)

The maintenance of hybrids by parasitism in a freshwater snail

International Journal for Parasitology, 2014
Hybrids have often been labelled evolutionary dead-ends due to their lower fertility and viability. However, there is growing awareness that hybridisation between different species may play a constructive role in animal evolution as a means to create variability.
Yonathan, Guttel, Frida, Ben-Ami
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Haemoglobin producing cells in freshwater snails

Zeitschrift f�r Zellforschung und Mikroskopische Anatomie, 1972
One of the cell types occurring in the connective tissue of gastropods and bivalves is thepore cell. Cells of this type have a characteristic morphology in that their plasmamembrane has many invaginations bridged by cytoplasmic tongues. In the well developed granular endoplasmic reticulum and in these invaginations fine granular material, sometimes ...
T, Sminia, H H, Boer, A, Niemantsverdriet   +2 more
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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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Monoamines and their metabolites in the freshwater snail Biomphalaria glabrata

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2000
Metabolism of the major monoamines and their functions were studied in the freshwater snail Biomphalaria glabrata. In both juvenile and adult snails, the plasma (cell-free hemolymph) appears to act as a reservoir for most of these monoamines and their metabolites including among others, L-dopa and dopamine as major constituents.
V, Santhanagopalan, T P, Yoshino
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Biological methods for the control of freshwater snails

Parasitology Today, 1990
As a result of the advent of new drugs and diagnostic techniques, the emphasis in the control of schistosomiasis has changed from snail control to chemotherapy for infected individuals. However, chemotherapy does not prevent reinfection and there remains a need to reduce snail densities in human water supplies. In the past, treatment with molluscicides
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Freshwater Snails Of Anwai River

2019
The Nigerian Field, 70 (1), 51 ...
Okonta, A A, Ogunbor, A O
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Comparative bioenergetics of freshwater snail populations

Die Naturwissenschaften, 1976
exaly   +2 more sources

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.
R T, Dillon, A R, Wethington
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The Land and Freshwater Snails of Campeche

Bulletin of the Florida Museum of Natural History, 1967
This review of the land and freshwater snails of Campeche, Mexico, records 59 species and subspecies of snails including 47 terrestrial and 12 acquatic forms; 21 are recorded for the first time from the state. Miradiscops haplocochlion is described as new; 11 previously recognized taxa are placed in synonymy.
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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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