Control of feeding movements in the freshwater snail Planorbis corneus

1988 ◽  
Vol 70 (2) ◽  
pp. 310-322 ◽  
Author(s):  
Yu. I. Arshavsky ◽  
T. G. Deliagina ◽  
E. S. Meizerov ◽  
G. N. Orlovsky ◽  
Yu. V. Panchin
Keyword(s):  
Freshwater Snail ◽  
Planorbis Corneus

Control of feeding movements in the freshwater snail Planorbis corneus

1988 ◽  
Vol 70 (2) ◽  
pp. 332-341 ◽  
Author(s):  
Yu. I. Arshavsky ◽  
T. G. Deliagina ◽  
G. N. Orlovsky ◽  
Yu. V. Panchin
Keyword(s):  
Freshwater Snail ◽  
Planorbis Corneus

Control of Locomotion in the Freshwater Snail Planorbis Corneus: I. Locomotory Repertoire of the Snail

1990 ◽  
Vol 152 (1) ◽  
pp. 389-404
Author(s):  
T. G. DELIAGINA ◽  
G. N. ORLOVSKY
Keyword(s):  
Nervous System ◽  
Water Surface ◽  
Anterior Part ◽  
Vertical Wall ◽  
Freshwater Snail ◽  
Diurnal Changes ◽  
Vertical Orientation ◽  
Planorbis Corneus ◽  
Food Particles ◽  
Sole Of The Foot

The freshwater snail Planorbis corneas moves as a result of the beating of cilia covering the sole of the foot. The tracks of snails crawling on the walls and on the bottom of an aquarium were recorded visually under various conditions of snail feeding. The following results were obtained. 1. In the absence of food, the snails exhibited diurnal changes in locomotor activity, with a maximum during the day. Horizontal tracks on the aquarium walls were commonest during the day and vertical ones at night. When crawling on the aquarium wall, the snail actively stabilized its horizontal or vertical orientation: when encountering an obstacle or after a forced turn, the snail re-established the initial direction of locomotion. 2. When fed on the water surface, the snail decreased its locomotor speed if food particles entered its mouth. The decrease in speed resulted from the slowing down of ciliary beating in the anterior part of the sole of the foot. This finding demonstrates that motor activity in different parts of the ciliated epithelium can be controlled independently by the nervous system. 3. When searching for food particles, the snail exhibited very sinuous tracks, the turns occurring spontaneously at irregular intervals. This finding shows that there is a programme of ‘looping’ in the nervous system. 4. When the snail was fed on the bottom near a vertical wall, it used the wall to climb to the water surface for lung ventilation. After ventilation, the snail performed a standard 180° turn and then returned to the food along the original outward track. Motion along a track was performed with high accuracy. 5. The locomotor apparatus of a snail allowed it to crawl not only on a flat surface but also along the very thin mucus thread that it makes.

Control of feeding movements in the freshwater snail Planorbis corneus

1988 ◽  
Vol 70 (2) ◽  
pp. 323-331 ◽  
Author(s):  
Yu. I. Arshavsky ◽  
T. G. Deliagina ◽  
G. N. Orlovsky ◽  
Yu. V. Panchin
Keyword(s):  
Freshwater Snail ◽  
Planorbis Corneus

scholarly journals Control of Locomotion in the Freshwater Snail Planorbis Corneus: II. Differential Control of Various Zones of the Ciliated Epithelium

1990 ◽  
Vol 152 (1) ◽  
pp. 405-423
Author(s):  
T. G. DELIAGINA ◽  
G. N. ORLOVSKY
Keyword(s):  
Locomotor Activity ◽  
Freshwater Snail ◽  
Ciliated Epithelium ◽  
Small Disk ◽  
Ciliary Beating ◽  
Tactile Stimuli ◽  
Neuronal Mechanisms ◽  
Planorbis Corneus ◽  
Differential Control ◽  
Spontaneous Fluctuations

In the freshwater snail Planorbis corneus, the neuronal mechanisms of the pedal ganglia that control ciliary locomotion were studied. The foot was attached to the bottom of a recording chamber with the ciliated epithelium facing upwards. To record the total motor effect produced by ciliary beating, a small disk with its edge lying on the sole of the foot was used. The ciliary beating forced the disk to rotate. In the pedal ganglia, efferent locomotor neurones (ELNs) were found, which control the locomotor activity of the ciliated epithelium. This locomotor activity increased with excitation of an ELN, and decreased with its inhibition. Axons of the ELNs, controlling the anterior, middle and posterior zones, traverse the corresponding pedal nerves. For the anterior zone, two ELNs were found. For the middle and posterior zones, only one ELN per zone was found. The activity of ELNs correlated with the intensity of ciliary beating during the following central and reflex influences upon the locomotor mechanisms: (1) spontaneous fluctuations of the locomotor activity, (2) changes of temperature, (3) transections of central connections (interganglionic connectives), (4) defensive reactions evoked by tactile stimuli or switching off the light, and (5) activation of feeding behaviour by natural stimuli. The data strongly suggest that ELNs are responsible for the differential control of locomotor activity in various zones of the ciliated epithelium during different behavioural acts.

Regeneration of Floodplain Biotopes on the Upper Rhine – The “Polder Altenheim” Case

1994 ◽  
Vol 29 (3) ◽  
pp. 281-288 ◽  
Author(s):  
A. Siepe
Keyword(s):  
Large Scale ◽  
Freshwater Snail ◽  
Red Alga ◽  
Flood Protection ◽  
Flooding Regime ◽  
Theodoxus Fluviatilis ◽  
The Creation ◽  
Early Succession ◽  
Upper Rhine

The floodplain of the Upper Rhine and its biocoenoses have, through different river-regulatory activities over the last 175 years, undergone large scale degradation. At the same time flood protection for the downstream inhabitants has been greatly reduced. For reasons of flood protection, the “Polder Altenheim” in Baden-Württemberg, Germany southwest of Strasbourg, France, with so called retention flooding, was put into operation in 1987. The original floodplain had been diked for the previous 17 years, during which no flooding occurred. Since 1989 “ecological flooding” also is carried out. This has assisted in the regeneration of floodplain biotopes and promoted the floodplain biotic communities and the readaption of the bioceonosis to a regular flooding regime. The creation of new floodplain biotopes of early succession stages, particularly through geomorphodynamic processes, has followed the more than ten flood ocassions and typical biotic communities have colonised these sites. This will be presented together with selected examples of terrestrial and limnical species and communities. The following species and communities will be discussed: kingfisher Alcedo atthis, carabid communities (Coleoptera), the red alga Hildenbrandia rivularis (Rhodophyceae), the freshwater snail Theodoxus fluviatilis (Neritacea) and the freshwater bug Aphelocheirus aestivalis (Hydrocorisae).

Pflanzenabwehrstoffe XXXI [1] Molluskizide Eigenschaften von Chinonen

1987 ◽  
Vol 42 (1-2) ◽  
pp. 31-32 ◽  
Author(s):  
Hermann Schildknecht ◽  
Johannes Lubosch
Keyword(s):  
Planorbis Corneus ◽  
Molluscicidal Activity

Abstract The quinone 2-methoxy-6-n-pentyl-2,5-cyclohexadien-1,4-dion (Primin) was found to possess molluscicidal activity against the snail Planorbis corneus. The synthesis of homologous and isomers and the results in the biotests are reported.

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