The Integration of Activity Cycles in the Behaviour of Arenicola Marina L

1951 ◽  
Vol 28 (1) ◽  
pp. 41-50
Author(s):  
G. P. WELLS ◽  
ELINOR B. ALBRECHT
Keyword(s):  
Body Wall ◽  
Sea Water ◽  
Rhythmic Activity ◽  
The Body ◽  
Neuromuscular System ◽  
Arenicola Marina ◽  
Cyclic Behaviour ◽  
Feeding Cycle ◽  
Activity Cycles ◽  
Set Up

1. Lugworms were dissected in such a way that the movements of the following parts could be simultaneously recorded: extrovert, body wall from the anterior three segments, body wall from the branchiate segments, tail. The preparations were set up in sea water and tracings were taken for many hours in each case. The preparations typically settled down to give cyclic behaviour patterns, remarkably similar to those which intact worms exhibit under favourable conditions, and in which two components were conspicuous. 2. The first, and most invariable, component is the feeding cycle (f cycle), of period 6-7 min. This rhythm originates in the oesophagus, and is transmitted to the muscles of the proboscis (where it causes outbursts of vigorous contraction) and body wall (where it causes correlated contractions in the first three segments, but periodic inhibition in the branchiate segments). 3. The second component was seen in two-thirds of the experiments. It consists of bursts of vigorous rhythmic activity in the body wall and tail, and can appear after their connexion with the extrovert has been severed. Under exceptional circumstances (exhaustion of the f cycle) it may spread to the extrovert trace. Its period is generally 20-60 min. It is apparently identical with the irrigation-defaecation cycle (i-d cycle) of intact worms. 4. Neither pacemaker directly affects the rhythm of the other. The integration of the activities which they determine probably depends on variation in the extent to which their influences spread through the neuromuscular system. They appear to compete for territory. If they happen to discharge outbursts simultaneously, the i-d pacemaker dominates over most of the body wall, and the f pacemaker over the proboscis and mouth region.

Excretion of thiosulphate, the main detoxification product of sulphide, by the lugworm arenicola marina L

1999 ◽  
Vol 202 (7) ◽  
pp. 855-866 ◽  
Author(s):  
K. Hauschild ◽  
W.M. Weber ◽  
W. Clauss ◽  
M.K. Grieshaber
Keyword(s):  
Body Wall ◽  
Sea Water ◽  
The Body ◽  
Cell Junctions ◽  
Metabolic Inhibitors ◽  
Coelomic Fluid ◽  
Arenicola Marina ◽  
Double Exponential ◽  
Electrophysiological Measurements ◽  
Double Exponential Function

Thiosulphate, the main sulphide detoxification product, is accumulated in the body fluids of the lugworm Arenicola marina. The aim of this study was to elucidate the fate of thiosulphate. Electrophysiological measurements revealed that the transepithelial resistance of body wall sections was 76+/−34 capomega cm2 (mean +/− s.d., N=14), indicating that the body wall of the lugworm is a leaky tissue in which mainly paracellular transport along cell junctions takes place. The body wall was equally permeable from both sides to thiosulphate, the permeability coefficient of which was 1. 31×10(−)3+/−0.37×10(−)3 cm h-1 (mean +/− s.d., N=30). No evidence was found for a significant contribution of the gills or the nephridia to thiosulphate permeation. Thiosulphate flux followed the concentration gradient, showing a linear correlation (r=0.997) between permeated and supplied (10–100 mmol l-1) thiosulphate. The permeability of thiosulphate was not sensitive to the presence of various metabolic inhibitors, implicating a permeation process independent of membrane proteins and showing that the lugworm does not need to use energy to dispose of the sulphide detoxification product. The present data suggest a passive permeation of thiosulphate across the body wall of A. marina. In live lugworms, thiosulphate levels in the coelomic fluid and body wall tissue decreased slowly and at similar rates during recovery from sulphide exposure. The decline in thiosulphate levels followed a decreasing double-exponential function. Thiosulphate was not further oxidized to sulphite or sulphate but was excreted into the sea water.

Heat transfer between fish and ambient water

1976 ◽  
Vol 65 (1) ◽  
pp. 131-145 ◽  
Author(s):  
E. D. Stevens ◽  
A. M. Sutterlin
Keyword(s):  
Body Wall ◽  
Sea Water ◽  
The Body ◽  
Direct Transfer ◽  
Major Fraction ◽  
Metabolic Heat ◽  
Sea Raven ◽  
Before And After ◽  
Ventral Aorta ◽  
Hemitripterus Americanus

1. The ability of fish gills to transfer heat was measured by applying a heat pulse to blood in the ventral aorta and measuring it before and after passing through the gills of a teleost, Hemitripterus americanus. 2. 80–90% of heat contained in the blood is lost during passage through the gills. 3. The fraction of heat not lost during passage through the gills is due to direct transfer of heat between the afferent and efferent artery within the gill bar. 4. The major fraction of metabolic heat (70 - 90%) is lost through the body wall and fins of the sea raven in sea water at 5 degrees C; the remainder is lost through the gills.

The Mechanism of Proboscis Movement in Arenicola

1954 ◽  
Vol s3-95 (30) ◽  
pp. 251-270
Author(s):  
G. P. WELLS
Keyword(s):  
Body Fluid ◽  
Body Wall ◽  
The Body ◽  
Stage I ◽  
Stage Iii ◽  
Forward Movement ◽  
Arenicola Marina ◽  
Buccal Mass ◽  
The Difference ◽  
Longitudinal Muscles

The mechanism of proboscis movement is analysed in detail in Arenicola marina L. and A. ecaudata Johnston, and discussed in relation to the properties of the hydrostatic skeleton. Proboscis activity is based on the following cycle of movements in both species. Stage I. The circular muscles of the body-wall and buccal mass contract; the head narrows and lengthens. Stage IIa. The circular muscles of the mouth and buccal mass relax; the gular membrane (or ‘first diaphragm’ of previous authors) contracts; the mouth opens and the buccal mass emerges. Stage IIb. The longitudinal muscles of the buccal mass and body-wall contract; the head shortens and widens and the pharynx emerges. Stage III. As Stage I. The two species differ anatomically and in their hydrostatic relationships. In ecaudata, the forward movement of body-fluid which extrudes and distends the proboscis is largely due to the contraction of the gular membrane and septal pouches. In marina, the essential mechanism is the relaxation of the oral region which allows the general coelomic pressure to extrude the proboscis. The gular membrane of marina contracts as that of ecaudata does, but its anatomy is different and it appears to be a degenerating structure as far as proboscis extrusion is concerned. Withdrawal of the proboscis may occur while the head is still shortening and widening in Stage IIb, or while it is lengthening and narrowing in Stage III. The proboscis is used both in feeding and in burrowing; in the latter case nothing enters through the mouth; the difference is largely caused by variation in the timing of withdrawal relative to the 3-stage cycle.

scholarly journals The Movements of the Proboscis in Glycera Dibranchiata Ehlers

1937 ◽  
Vol 14 (3) ◽  
pp. 290-301
Author(s):  
G. P. WELLS
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Wall ◽  
The Body ◽  
Inhibitory Influence ◽  
Spontaneous Movement ◽  
Arenicola Marina ◽  
Glycera Dibranchiata ◽  
The Central Nervous System ◽  
Nervous Conduction

1. The gut of Glycera consists of (a) the buccal tube, (b) the pharynx, containing the jaws with their associated muscles and glands and the principal stomatogastric ganglia, (c) the oesophagus, leading from the pharynx to (d) the intestine, in which digestion occurs. 2. An "isolated extrovert" preparation is described, consisting of the buccal tube, pharynx and oesophagus. The movements of the buccal tube and oesophagus are recorded separately. The preparation has the following properties: (a) The buccal tube shows vigorous, rapid contractions with a somewhat irregular rhythm. These contractions are due to impulses coming forwards from the pharynx, the buccal tube itself having little power of spontaneous movement. (b) The oesophagus shows tone-waves, on which more rapid contractions of small amplitude may be superposed. These contractions and tone-waves are due to impulses originating in the wall of the oesophagus itself. (c) In a few preparations only, synchronous movements of buccal tube and oesophagus were seen. The site of origin of this synchronous activity was not determined. 3. An "extrovert-body wall" preparation is described, in which the movements of the body wall and buccal tube are separately recorded while the normal nervous conduction paths between them remain intact. The preparation has the following properties: (a) In most cases the body wall shows slight movements only, and the buccal tube moves little or not at all. If, however, the buccal tube be cut across close to the mouth, it begins an irregular rhythm of vigorous contractions, due to impulses originating in the pharynx, which usually continues without diminution for hours. The quiescence of the buccal tube before this cut is made indicates that the central nervous system normally exerts an inhibitory influence on the pharynx. (b) In a few preparations, correlated outbursts of contraction in the body wall and buccal tube were seen. These outbursts, which possibly correspond to extrusion movements of the intact worm, are due to impulses originating in the central nervous system. 4. The results are compared with those previously obtained on Arenicola marina, and reported in an earlier paper.

scholarly journals Physiological Effects of a Hypotonic Environment

1940 ◽  
Vol 17 (3) ◽  
pp. 337-352
Author(s):  
G. P. WELLS ◽  
ISABEL C. LEDINGHAM
Keyword(s):  
Body Wall ◽  
Sea Water ◽  
Rapid Change ◽  
Natural Conditions ◽  
Bathing Medium ◽  
Nereis Diversicolor ◽  
Arenicola Marina ◽  
Lower Salinity ◽  
Hypotonic Fluid ◽  
Two Phases

1. The reactions of isolated rhythmic preparations from Arenicola marina, Nereis diversicolor and Perinereis cultrifera to hypotonic saliness are described. 2. The preparations used were (1) the "isolated extrovert" of all three species, (2) ventral longitudinal body-wall strips of the two last named. All these preparations are essentially alike in their reactions to dilution of the bathing medium. 3. On abruptly changing from sea water to a hypotonic fluid, responses of the following general type are seen: first, brief excitement; then a phase of more or less complete inhibition; finally, provide the hypotonic fluid is not below a lower salinity limit characteristic of the preparation, gradual return of activity as the preparation accommodates itself to the new medium. The first two phases are shock effects of sudden dilution. The inhibition phase may last for many hours. 4. Preparations were exposed to salinities which fell gradually at various speeds. From the results of these experiments it is inferred that shock effects of rapid change are unlikely to be evoked under natural conditions, at least in Arenicola and Nereis. 5. The lower salinity limits for spontaneous activity in the tissues of the various species are: Perinereis cultrifera, 20-25% sea water; Arenicola marina, 15-20%; Nereis diversicolor, 5-10%. The results are discussed with reference to the ability to live in brackish water. 6. On suddenly returning from a hypotonic fluid to normal the responses vary. There may be relatively slight excitation (Arenicola marina extrovert) or a cycle of excitation--inhibition--accommodation like that evoked by a sudden downward change (Nereis diversicolor body wall).

Survival of Anaerobic Periods By Two Intertidal Polychaetes, Arenicola Marina (L.) and Owenia Fusiformis Delle Chiaje

1958 ◽  
Vol 37 (2) ◽  
pp. 521-529 ◽  
Author(s):  
R. Phillips Dales
Keyword(s):  
Oil Content ◽  
Body Wall ◽  
Normal Activity ◽  
The Body ◽  
Oxygen Debt ◽  
Anaerobic Conditions ◽  
Arenicola Marina ◽  
Coelomic Cells ◽  
Lactate And Pyruvate ◽  
Glycogen Breakdown

Measurements of glycogen in the body wall of Arenicola indicate that glycogen is consumed during anaerobic conditions. Estimations of lactate and pyruvate show that neither is accumulated, accounting for the absence of an oxygen debt previously found by other workers, and suggesting that glycogen breakdown leads to other acids. In Owenia most of the glycogen is stored in coelomic cells and these deposits are not drawn upon during anaerobic periods, yet this species can survive long periods without oxygen, apparently by becoming quiescent. Oil content in both species has also been measured, and was found not to fall under anaerobic conditions. It is suggested that survival of anaerobic periods may be mainly due to an ability to suspend normal activity.

The spatial relationship between the musculature and the 5-HT and FMRFamide immunoreactivities in cercaria, metacercaria and adult Opisthorchis felineus (Digenea)

2010 ◽  
Vol 55 (2) ◽  
Author(s):  
Oleg Tolstenkov ◽  
Nadezhda Terenina ◽  
Elena Serbina ◽  
Margaretha Gustafsson
Keyword(s):  
Nervous System ◽  
Body Wall ◽  
General Pattern ◽  
Spatial Relationship ◽  
The Body ◽  
Muscle Fibres ◽  
Neuromuscular System ◽  
Opisthorchis Felineus ◽  
Larval Stages ◽  
The Individual

AbstractThe organisation of the neuromuscular system in cercariae, metacercariae and adult Opisthorchis felineus was studied. The patterns of nerves immunoreactive (IR) to antibodies towards serotonin (5-HT) and FMRFamide are described in relation to the musculature, stained with TRITC-conjugated phalloidin. The general organisation of the musculature in the body wall, suckers, pharynx, intestine and sphincter of the excretory pore remains the same from the larval stages to the adult worms. However, the diameter of the individual muscle fibres increases distinctly in the adult worms. The general pattern of 5-HT IR fibres in cercariae, metacercariae and adult O. felineus remains the same. Despite the large increase in body size, the number of 5-HT IR neurones remains almost the same in the cercariae and metacercariae and only a modest increase in number of neurones was observed in the adult worms. Thus the proportion of 5-HT IR neurones/body mass is greatest in the actively moving cercariae. Anti-FMRFamide stains the nervous system strongly.

scholarly journals Viscoelasticity of Holothurian Body Wall

1984 ◽  
Vol 109 (1) ◽  
pp. 63-75 ◽  
Author(s):  
TATSUO MOTOKAWA
Keyword(s):  
Mechanical Model ◽  
Body Wall ◽  
Sea Water ◽  
Elastic Stiffness ◽  
Chemical Stimulation ◽  
The Body ◽  
Connective Tissues ◽  
Creep Tests ◽  
Covalent Bonds ◽  
Viscosity Change

1. Stress-relaxation tests and creep tests were performed on the body-wall dermis of two sea cucumbers, Actinopyga echinites (Jäger) and Holothuria leucospilota Brandt. 2. These viscoelastic connective tissues had mechanical properties which agreed well with those of a four-element mechanical model composed of two Maxwell elements connected in parallel. 3. The elastic stiffness of the dermis of Actinopyga was 1.7 MPa and that of Holothuria was 042 MPa. 4. The viscosity of the dermis showed great variation of more than two orders. 5. Chemical stimulation with artificial sea water containing 100 mM potassium increased the viscosity but not elasticity. 6. The viscosity change is suggested to be caused by the change in weak (non-covalent) bonds between macromolecules which constitute the dermis.

scholarly journals Adaptation to Changes of Salinity in the Polychaetes

1937 ◽  
Vol 14 (1) ◽  
pp. 56-70
Author(s):  
L. C. BEADLE
Keyword(s):  
Hydrostatic Pressure ◽  
Body Wall ◽  
Sea Water ◽  
Calcium Deficiency ◽  
Body Fluids ◽  
The Body ◽  
Concentration Curve ◽  
Body Volume ◽  
Weight Curve ◽  
Body Wall Muscles

1. Nereis diversicolor collected from the same locality at different times showed smaller weight increases in dilute sea water (25 per cent) during the winter than during the summer months. 2. In spite of great variations in the weight curve, the body fluid concentration curve was very constant. 3. The maintenance of hypertonic body fluids and the regulation of body volume are largely unconnected. 4. The lowering of the weight curve below that theoretically expected from the concentration curve cannot be attributed to passive salt loss through the body surface. It is suggested that this is due to the removal of fluid through the nephridia under the hydrostatic pressure produced by the contraction of the body wall muscles. 5. Animals previously subjected to dilute sea water, when placed in water isotonic with the body fluids, will increase the concentration of the latter. This result is more marked when the internal hydrostatic pressure is high. 6. The results suggest that the osmotic regulatory mechanism involves the removal by the nephridia of fluid hypotonic to the body fluids. But no direct evidence for this is available. 7. Calcium deficiency and cyanide in dilute sea water cause an increase of weight and ultimately inhibit the maintenance of hypertonic body fluids. Both these effects are reversible. 8. The mechanism by which body fluids are maintained hypertonic to the external medium is not sufficiently developed to be of survival value in the locality in which the animals were found. 9. The control of body volume is probably of greater importance. 10. The majority of the extra oxygen consumption in dilute sea water is not the result of osmotic work. It is suggested that it may be due to work done by the body wall muscles in resisting swelling.

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