Observations on the Effects of Changes of Hydrostatic Pressure on the Behaviour of Some Marine Animals

1964 ◽  
Vol 44 (1) ◽  
pp. 163-175 ◽  
Author(s):  
A. L. Rice
Keyword(s):  
Hydrostatic Pressure ◽  
Experimental Method ◽  
Relative Importance ◽  
Marine Plankton ◽  
Marine Animals ◽  
The Hours ◽  
Gravity Receptors ◽  
Pressure Changes ◽  
Increased Activity ◽  
Increased Pressure

An apparatus and experimental method for the investigation of the effects of changes of pressure on the behaviour of marine animals is described.In 43 of a total of 53 species examined in this apparatus definite responses to abrupt pressure changes of 1000 millibars or less have been observed, increased pressure generally causing increased activity and movement upwards or towards the light, and decreased pressure causing decreased activity and movement downwards or away from the light. The relative importance of light and gravity in the orientation of these movements is generally correlated with the degree of development of the light and gravity receptors in the species concerned.The possible significance of these pressure responses in nature is discussed and it is suggested that pressure may be an important factor affecting the distribution of marine plankton, particularly during the hours of darkness.

The Effect of Hydrostatic Pressure Cycles on the Activity of Young Plaice Pleuronectes Platessa

1982 ◽  
Vol 62 (3) ◽  
pp. 621-635 ◽  
Author(s):  
R. N. Gibson
Keyword(s):  
Hydrostatic Pressure ◽  
Recent Work ◽  
Marine Animals ◽  
Pleuronectes Platessa ◽  
Pressure Changes ◽  
Effect Of Hydrostatic Pressure ◽  
Gradual Pressure

The responses of marine animals to changes in hydrostatic pressure have been widely studied (see reviews by Knight-Jones & Morgan, 1966; Fliigel, 1972; Nay lor & Atkinson, 1972). Most of these studies, however, have been concerned with invertebrates, particularly Crustacea, and few deal with fish (Gordon, 1970). Blaxter's (1978) review of baroreception summarizes recent work in this field and points out that a limitation of many experiments has been the use of sudden, rather than gradual, pressure changes. The limitation is especially true with respect to fish. This paper describes the results of experiments in which young plaice (Pleuronectes platessa L.) were subjected to hydrostatic pressure cycles of varying amplitude and frequency in order to describe the response to such pressure cycles, to determine the threshold of the response and to relate the response to the fish's behaviour in the sea.

Implosion of living Nautilus under increased pressure

Paleobiology ◽  
1980 ◽  
Vol 6 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Yasumitsu Kanie ◽  
Yoshio Fukuda ◽  
Hideaki Nakayama ◽  
Kunihiro Seki ◽  
Mutsuo Hattori
Keyword(s):  
Hydrostatic Pressure ◽  
Hyperbaric Chamber ◽  
Depth Limit ◽  
Mature Specimen ◽  
Nautilus Pompilius ◽  
Increased Pressure

In a hyperbaric chamber, a living mature specimen of Nautilus pompilius withstood a hydrostatic pressure of 8.05 MPa (80.5 kg/cm2) equivalent to 785 m deep in the sea. Thereafter it was killed instantly by implosion of the shell. Before implosion, the animal reacted physiologically to increasing pressure. Therefore, the depth of 785 m can be assigned the depth limit of N. pompilius. The result bears on critical interpretations on the paleoecology and paleobiology of extinct nautiloids and ammonoids with similar shells.

The Distribution of P O2 and Hydrostatic Pressure Changes Within the Branchial Chambers in Relation to GILL VENTILATION OF THE SHORE CRAB CARCINUS MAENAS L

1969 ◽  
Vol 51 (1) ◽  
pp. 203-220
Author(s):  
G. M. HUGHES ◽  
B. KNIGHTS ◽  
C. A. SCAMMELL
Keyword(s):  
Hydrostatic Pressure ◽  
Ventilation System ◽  
Carcinus Maenas ◽  
Pressure Change ◽  
Shore Crab ◽  
Positive Pressure ◽  
Transparent Plastic ◽  
Gill Lamellae ◽  
Minimum Disturbance ◽  
Pressure Changes

1. A technique is described for replacing part of the branchiostegite of Carcinus maenas by a transparent plastic ‘window’ for direct observation of the gills in situ with minimum disturbance. 2. Observation of dye streams shows that most water enters the hypobranchial space through the Milne-Edwards openings above the chelae, flowing anteriorly and/or posteriorly to ventilate most of gills 3-8. Water also enters above the pereiopods to ventilate the rest of the gills. Water passes from the hypobranchial to the epibranchial space, confirming that there is a counterflow with respect to the circulation of blood through the gill lamellae. 3. By sampling water at different points in the branchial system, patterns of oxygen removal were studied. The gradients confirmed the direction of water flow observed by the use of dyes. 4. Rhythmic changes in hydrostatic pressure in normal forward-pumping of 3-12 mm. H2O were recorded from the branchial cavities, superimposed on a maintained negative pressure relative to that outside the crab of 0-10 mm. H2O. Reversals produced a brief positive pressure change of 0-22 mm. H2O. 5. The possible relationships of the rhythmic pressure changes to scaphognathite movements are discussed. 6. The role of reversals is discussed and it is concluded that their primary function during ventilation is in helping to clean the ventrally facing gill surfaces. But they are also important in respiration under certain special conditions which arise during the normal life of the animal. 7. The utilization of O2 during its passage over the gills is low (7-23%) in spite of the counterflow. Possible explanations of this are discussed in relation to a model of the whole ventilation system.

Changes of Internal Hydrostatic Pressure and Body Shape in Acanthocephalus Ranae

1966 ◽  
Vol 45 (2) ◽  
pp. 197-202
Author(s):  
R. A. HAMMOND
Keyword(s):  
Hydrostatic Pressure ◽  
Internal Pressure ◽  
Body Length ◽  
Body Shape ◽  
Muscular Activity ◽  
The Body ◽  
Trunk Muscles ◽  
Rapid Rise ◽  
Indirect Methods ◽  
Pressure Changes

1. Two indirect methods for recording changes of hydrostatic pressure within the trunk of Acanthocephalus ranae have been described. 2. Internal pressure has been shown to be lowest when the trunk is fully contracted and the proboscis invaginated, and highest when the trunk is fully elongated. 3. A rapid rise of internal pressure occurs when the circular trunk muscles contract. 4. Overall internal pressure changes of up to 0.5 cm. Hg have been shown to occur in active specimens. 5. The body length when fully extended is only 40-50% greater than when contracted. 6. The correlation between muscular activity, body shape, and internal hydrostatic pressure in A. ranae is discussed

Hematologic response of fish to changes in gas or hydrostatic pressure

1980 ◽  
Vol 239 (1) ◽  
pp. R161-R167 ◽  
Author(s):  
E. Casillas ◽  
L. S. Smith ◽  
J. J. Woodward ◽  
B. G. D'Aoust
Keyword(s):  
Hydrostatic Pressure ◽  
Plasma Proteins ◽  
Fibrinolytic Activity ◽  
Coagulation System ◽  
Related Phenomenon ◽  
Protein Levels ◽  
Diffuse Intravascular Coagulation ◽  
Rapid Decompression ◽  
Increased Pressure ◽  
Increased Susceptibility

Hematologic changes were studied in fingering salmon after rapid decompression from combined or independent exposure to gas and hydrostatic pressure. After decompression, fingerling salmon saturated with excess gas under pressure (10.1-40.6 m of seawater) suffered a decrease in thrombocyte counts and fibrinogen, prolonged prothrombin (PT) times, and increased fibrinolytic activity, plasma proteins, and erythrocyte counts in proportion to severity of the dive. After decompression, fingerling salmon exposed to increased pressure experienced an increase in thrombocyte counts and available fibrinogen, shortened PT times, increased erythrocyte counts, and decreased plasma protein levels. It appeared that pressure causes activation of the blood coagulation system of fish. This activation may predispose the fish to increased susceptibility to bubble-induced diffuse intravascular coagulation after rapid decompression. Furthermore, hemoconcentration after decompression may be a pressure-related phenomenon and not a response to bubble-induced anoxia.

Clinical study: Changes in interface pressure and stump shape over time: Preliminary results from a transtibial amputee subject

2000 ◽  
Vol 24 (2) ◽  
pp. 163-168 ◽  
Author(s):  
J. E. Sanders ◽  
J. M. Greve ◽  
C. Clinton ◽  
B. J. Hafner
Keyword(s):  
Clinical Study ◽  
Soft Tissue ◽  
Interface Pressure ◽  
Preliminary Results ◽  
Tissue Identification ◽  
Pressure Changes ◽  
Interface Pressures ◽  
Changes Over Time ◽  
Over Time ◽  
Increased Pressure

Interface stresses and stump shape were measured during sessions over a twomonth interval on a transtibial amputee subject. Results from thirteen transducer sites monitored during four sessions showed greater interface pressure changes over time at anterior sites than at lateral or posterior locations. There was a trend of decreased pressure with stump swelling and increased pressure for stump atrophy. During one session in which stump shape was monitored over a 23.1 min interval after ambulation, stump swelling was localised. Swelling tended to increase in the regions of initial enlargement, as opposed to redistributing through different areas over time. Regions of swelling were anterior lateral and posterior proximal, areas of thick underlying soft tissue. Identification of localised areas of swelling and atrophy and understanding of their effects on interface pressures could be used to improve individual socket design.

Integration of Hydrostatic Pressure Information by Identified Interneurones in the Crab Carcinus maenas (L.); Long-Term Recordings

2001 ◽  
Vol 54 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. J. Fraser ◽  
A. G. Macdonald ◽  
S. F. Cruickshank ◽  
M. P. Schraner
Keyword(s):  
Hydrostatic Pressure ◽  
Gas Phase ◽  
Progress Monitoring ◽  
Carcinus Maenas ◽  
Shore Crab ◽  
Pressure Sensitive ◽  
Animal Navigation ◽  
Tidal Changes ◽  
Pressure Changes

This paper was first presented at the RIN97 Conference held in Oxford under the auspices of the Animal Navigation Special Interest Group, April 1997.Migrating species may utilise hydrostatic pressure. In the aquatic environment, hydrostatic pressure changes much more rapidly than in air. In shallow water, tidal changes will impose larger percentage changes on organisms than those experienced in deep water. Small changes in pressure often cause locomotion (barokinesis) accompanied by orientation to light or gravity, often partially compensating for the equivalent depth change. Until recently, identification of hydrostatic pressure receptors without a gas phase has proved elusive, but it is now known that thread hair receptors in the statocyst of the shore crab Carcinus maenas respond to small changes in hydrostatic pressure. Using a tide machine, the responses of thread hairs to sinusoidally changing pressure cycles have been examined, and this paper reports progress monitoring this receptor and making long-term recordings from hydrostatic pressure sensitive pathways in the crab's nervous system.

A field method for measurement of gas diffusion into soils

Soil Research ◽  
1964 ◽  
Vol 2 (2) ◽  
pp. 133 ◽  
Author(s):  
DS McIntyre ◽  
JR Philip
Keyword(s):  
Theoretical Analysis ◽  
Experimental Method ◽  
Diffusion Coefficients ◽  
Field Measurement ◽  
Field Method ◽  
Gas Diffusion ◽  
Relative Importance ◽  
Transient Method ◽  
Apparatus Design ◽  
Laboratory Conditions

A transient method for field measurement of gas diffusion into soil is presented. The theory of the method and the results of preliminary tests are given. Diffusion takes place from a reservoir mounted on a tube driven into the soil. The theoretical analysis is used in the design of the experimental method, the relative importance of the various parameters involved in apparatus design and in measurement being evaluated. The apparatus is described and sample calculations of parameters given. When porosity is uniform with depth, diffusion coefficients obtained in the field agree well with results of diffusion measurements of other workers made under better controlled (laboratory) conditions.

Effect of High Hydrostatic Pressure on the Permeability of Elastomers to Water

1966 ◽  
Vol 39 (4) ◽  
pp. 1298-1307 ◽  
Author(s):  
Alexander Lebovits
Keyword(s):  
Hydrostatic Pressure ◽  
Thermodynamic Analysis ◽  
Atmospheric Pressure ◽  
High Hydrostatic Pressure ◽  
Polymeric Materials ◽  
Butyl Rubber ◽  
Pressurized Water ◽  
Simple Method ◽  
Increased Pressure

Abstract The permeability of butyl rubber to pressurized water was measured at 10,000 psi hydrostatic pressure using a relatively simple method which consisted of constructing pouches from rubber, filling these with desiccant and exposing them to pressurized water. At this high hydrostatic pressure the permeability was found to be smaller than at atmospheric pressure which suggests the suitability of butyl rubber for the construction of hydrophone boots used at great depths. Similar results found by other investigators for other polymeric materials are cited. A thermodynamic analysis of the process of permeation by activated diffusion was made and a mechanism was discussed which explains the decrease in permeability of butyl rubber to water with increased pressure.

The Responses of Nephtys (Polychaeta: Annelida) to Changes in Hydrostatic Pressure

1969 ◽  
Vol 50 (2) ◽  
pp. 501-513
Author(s):  
ELFED MORGAN
Keyword(s):  
Hydrostatic Pressure ◽  
Phase Angle ◽  
Pressure Change ◽  
Stimulus Level ◽  
Rate Of Change ◽  
Swimming Activity ◽  
Sine Function ◽  
Pressure Changes

1. An increase in pressure elicited swimming in Nephtys, the number of worms induced to swim being related to the amplitude of the pressure change within the range of stimuli investigated. A decrease in pressure inhibited swimming. 2. The latency of the response to both an increase and a decrease also appears to be related to the magnitude of the stimulus, the worms responding more rapidly to the bigger pressure changes. 3. Brief pulses of pressure lasting 1 sec. elicited neither increase nor decrease in the level of swimming, but pulses of 5 sec. duration induced some individuals to swim. Releasing the pressure at the end of the 5 sec. period resulted in a decrease in the swimming activity below the pre-stimulus level. It is suggested that the different responses may be mediated via separate receptor mechanisms. 4. Phase-angle analysis of the responses to cyclical changes in pressure suggested that the worms were responding primarily to the rate of change of pressure, but the response did not appear to be a simple sine-function of the stimulus. The worms also seemed to be responding in part to some component occurring at twice the basic cycle.

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