Osmotic relations of the coelomic fluid and body wall tissues in Arenicola marina subjected to salinity change

1979 ◽  
Vol 13 (3-4) ◽  
pp. 536-546 ◽  
Author(s):  
R.E. Weber ◽  
D.H. Spaargaren
Keyword(s):  
Body Wall ◽  
Coelomic Fluid ◽  
Salinity Change ◽  
Arenicola Marina

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.

Ventilatory and metabolic responses to hypoxia and sulphide in the lugworm Arenicola marina (L.)

2000 ◽  
Vol 203 (20) ◽  
pp. 3177-3188 ◽  
Author(s):  
S.E. Wohlgemuth ◽  
A.C. Taylor ◽  
M.K. Grieshaber
Keyword(s):  
Body Wall ◽  
Oxygen Deficiency ◽  
Ventilation Rate ◽  
The Body ◽  
Coelomic Fluid ◽  
Moderate Hypoxia ◽  
Arenicola Marina ◽  
Sulphide Concentration ◽  
Aerobic Energy Metabolism ◽  
Ventilation Rates

We examined the effects of hypoxia and sulphide levels on the ventilatory activity of Arenicola marina and determined whether ventilation compensates for oxygen deficiency and affects the mode of energy provision. A. marina ventilated intermittently, irrespective of ambient P(O2) and sulphide concentration. The ventilation rate was 28.5+/−16 ml h(−1) g(−1) wet mass during normoxia, but increased to 175+/−60% of this value during moderate hypoxia, during which aerobic energy metabolism was maintained. Below a P(O2) of 6.2 kPa, A. marina reduced the ventilated volume to 54+/−16% of the normoxic value and became anaerobic, as indicated by the accumulation of succinate and strombine. Incubation with 27 micromol l(−1) ambient sulphide had no effect on the normoxic and hypoxic ventilation rates or on the P(O2) below which anaerobiosis started (P(cM)). Increased sulphide concentrations reduced the ventilation rate and shifted the P(cM) towards a higher P(O2) below 10.7 kPa. Sulphide diffused into the body and was at least partially detoxified to thiosulphate when oxygen was present. Under normoxia, sulphide accumulated in the body wall tissue and coelomic fluid when ambient sulphide levels exceeded 117 micromol l(−1) and 216 micromol l(−1), respectively. A decrease in P(O2) in the presence of 27 or 117 micromol l(−1) ambient sulphide had no significant effect on sulphide accumulation.

The Ligamentary System and the Segmental Musculature of Nephtys

1960 ◽  
Vol s3-101 (54) ◽  
pp. 149-176
Author(s):  
R. B. CLARK ◽  
M. E. CLARK
Keyword(s):  
Body Wall ◽  
The Body ◽  
Power Stroke ◽  
Coelomic Fluid ◽  
Unusual Structure ◽  
Shock Absorbers ◽  
Proximal Half ◽  
Unique System ◽  
Body Wall Muscles ◽  
The Impact

Nephtys lacks circular body-wall muscles. The chief antagonists of the longitudinal muscles are the dorso-ventral muscles of the intersegmental body-wall. The worm is restrained from widening when either set of muscles contracts by the combined influence of the ligaments, some of the extrinsic parapodial muscles, and possibly, to a limited extent, by the septal muscles. Although the septa are incomplete, they can and do form a barrier to the transmission of coelomic fluid from one segment to the next under certain conditions, particularly during eversion of the proboscis. Swimming is by undulatory movements of the body but the distal part of the parapodia execute a power-stroke produced chiefly by the contraction of the acicular muscles. It is suspected that the extrinsic parapodial muscles, all of which are inserted in the proximal half of the parapodium, serve to anchor the parapodial wall at the insertion of the acicular muscles and help to provide a rigid point of insertion for them. Burrowing is a cyclical process involving the violent eversion of the proboscis which makes a cavity in the sand. The worm is prevented from slipping backwards by the grip the widest segments have on the sides of the burrow. The proboscis is retracted and the worm crawls forward into the cavity it has made. The cycle is then repeated. Nephtys possesses a unique system of elastic ligaments of unusual structure. The anatomy of the system is described. The function of the ligaments appears to be to restrain the body-wall and parapodia from unnecessary and disadvantageous dilatations during changes of body-shape, and to serve as shock-absorbers against the high, transient, fluid pressures in the coelom, which are thought to accompany the impact of the proboscis against the sand when the worm is burrowing. From what is known of its habits, Nephtys is likely to undertake more burrowing than most other polychaetes.

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 A role for adenosine in metabolic depression in the marine invertebrate Sipunculus nudus

1997 ◽  
Vol 272 (1) ◽  
pp. R350-R356 ◽  
Author(s):  
A. Reipschlager ◽  
G. E. Nilsson ◽  
H. O. Portner
Keyword(s):  
Body Wall ◽  
Marine Invertebrate ◽  
Coelomic Fluid ◽  
Metabolic Depression ◽  
O2 Consumption ◽  
Experimental Conditions ◽  
Indwelling Catheter ◽  
Sipunculus Nudus ◽  
Body Wall Musculature ◽  
Concentration Changes

Involvement of neurotransmitters in metabolic depression under hypoxia and hypercapnia was examined in Sipunculus nudus. Concentration changes of several putative neurotransmitters in nervous tissue during anoxic or hypercapnic exposure or during combined anoxia and hypercapnia were determined. Among amino acids (gamma-aminobutyric acid, glutamate, glycine, taurine, serine, and aspartate) and monoamines (serotonin, dopamine, and norepinephrine), some changes were significant, but none were consistent with metabolic depression under all experimental conditions applied. Only the neuromodulator adenosine displayed concentration changes in accordance with metabolic depression under all experimental conditions. Levels increased during anoxia, during hypercapnia, and to an even greater extent during anoxic hypercapnia. Adenosine infusions into coelomic fluid via an indwelling catheter induced a significant depression of the normocapnic rate of O2 consumption from 0.36 +/- 0.04 to a minimum of 0.24 +/- 0.02 (SE) mumol.g-1.h-1 after 90 min (n = 6). Application of the adenosine antagonist theophylline caused a transient rise in O2 consumption 30 min after infusion during hypercapnia but not during normocapnia. Effects of adenosine and theophylline were observed in intact individuals but not in isolated body wall musculature. The results provide evidence for a role of adenosine in inducing metabolic depression in S. nudus, probably through the established effects of decreasing neuronal excitability and neurotransmitter release. In consideration of our previous finding that metabolic depression in isolated body wall musculature was elicited by extracellular acidosis, it is concluded that central and cellular mechanisms combine to contribute to the overall reduction in metabolic rate in S. nudus.

scholarly journals Estabilidade osmótica dos fluídos celômicos de um pepino do mar (Holothuria grisea) e de uma estrela-do-mar (Asterina stellifera) (Echinodermata) expostos ao ar durante a maré baixa: um estudo de campo

2002 ◽  
Vol 31 ◽  
Author(s):  
DENILTON VIDOLIN ◽  
IVONETE A. SANTOS GOUVEA ◽  
CAROLINA A. FREIRE
Keyword(s):  
Body Wall ◽  
Sea Water ◽  
Weather Conditions ◽  
Coelomic Fluid ◽  
Slight Reduction ◽  
Air Exposure ◽  
Water Influx ◽  
Sunny Weather ◽  
Wall Permeability ◽  
Water Gain

Animais de entre-marés podem ser expostos ao ar durante a maré baixa, por pelo menos 1-2 horas. Os animais expostos ao ar são susceptíveis a perda de sal e/ou entrada de água durante chuva intensa, ou perda de água pela ação de dessecação do sol. A osmolalidade de amostras de fluido celômico obtidas do pepino-do-mar Holothuria grisea e da estrela-do-mar Asterina stellifera expostas ao ar, ou de animais controles imersos na água do mar adjacente foi determinada. As amostras foram obtidas imediatamente após a exposição ao ar, e novamente após uma hora de exposição ao ar, durante a maré baixa no campo, em tempo nublado, chuvoso, ou ensolarado, na Praia rochosa do Quilombo, Penha, Sul do Brasil. Uma hora de exposição a qualquer das condições climáticas indicadas não alterou a osmolalidade dos fluidos celômicos. Houve pequena redução nas osmolalidades dos fluidos celômicos durante a exposição ao ar com precipitação de chuva. Sugere-se que estes equinodermas possam imediatamente detectar sua exposição ao ar, e possam então reduzir a permeabilidade osmótica de sua parede do corpo, para evitar perda de água para o ar ou entrada de água/saída de sal durante a chuva. ABSTRACT Intertidal animals can be exposed to the air during low tide, for at least 1-2 hours. Animals exposed to the air are subject to salt loss (or water gain) from heavy rains or volume loss from the desiccating action of the sun. Coelomic fluid samples obtained from the sea-cucumber Holothuria grisea and the starfish Asterina stellifera exposed to the air or from control animals submerged in surrounding sea water have been assayed for osmolality. Samples were obtained right after air exposure and again after 1 hour of exposure to the air during low tide in the field, either under cloudy, rainy or sunny weather conditions, in the rocky beach of Quilombo, Penha, Southern Brazil. One hour of exposure to any of the conditions did not change coelomic fluid osmolalities. There was a slight reduction in coelomic fluid osmolalities upon air exposure during rainfall. It is suggested that these echinoderms can somehow immediately detect air exposure and reduce their body wall permeability to avoid water loss or water influx/salt loss during rainfall. RÉSUMÉ Animaux d’entre-marées peuvent êtres exposés a l’air libre pendant le reflux de la marée, pour environ une ou deux heures seulement. Ces animaux, quand exposés a l’air libre, sont susceptibles de perdre du sel et d’absorber de l’eau pendant une période de pluie intense. Par contre, ils peuvent perdre de l’eau si soumis a l’action de dessèchement due a une éxposition au soleil. On a réussi a determiner l’osmolalité d’échantillons du fluide celomique obtenus du Pépin-de-mer Holothuria grisea et de l’Étoile-de-mer Asterina stellifera exposés a l’air libre, e d’animaux-controles immergés dans l’eau de mer voisin. Les échantillons ont été obtenus tout de suite après l’exposition à l’air et, une seconde fois, après une heure d’exposition à l’air libre, pendant la durée de la marée basse, soit sous la pluie, soit au soleil ou soit sous un ciel ombrageux, à la plage rocailleuse de Quilombo, Penha, au sud du Brésil. Une heure d’éxposition à n’importe quelles conditions climatiques indiquées, n’ont pas pu altérer l’osmolalité des fluides celomiques, ce que sugère la conclusion que ces échinodermes peuvent détecter immédiatement sa exposition à l’air libre et peuvent tout de suite réduire la permeabilité osmotique de la membrane que recouvre son corps pour éviter perdre d’eau et, de la même façon, reduire l’absortion de l’eau pendant la pluie. On a observé une petite réduction de fluides celomiques pendant l’exposition a l’air, avec ocurrence de pluie.

Observations in the Skin Pigment and Amoebocytes, and the Occurrence of Phenolases in the Coelomic Fluid of Holothuria Forskali Delle Chiaje

1953 ◽  
Vol 31 (3) ◽  
pp. 529-539 ◽  
Author(s):  
Norman Millott
Keyword(s):  
Body Wall ◽  
Black Body ◽  
The Body ◽  
Coelomic Fluid ◽  
Histological Evidence ◽  
Oxidase System ◽  
Complete Investigation ◽  
Skin Pigment

The black body-wall pigment of Holothuria forskali shows the characteristics of melanin.From histological evidence it appears that the pigment is formed in association with the amoebocytes of the coelomic fluid, which eliminate the pigment in the body wall.The amoebocytes contain a phenolase system, distinct from the cytochromecytochrome oxidase system, with the properties of tyrosinase.The relation of these findings to those of a preceding and more complete investigation into melanogenesis in Diadema is discussed.

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