Osmoregulation in the Lobster Homarus americanus

Lobsters took 72 hr to adapt to a salinity of 20‰, with urine becoming markedly hypoosmotic to the blood during the first 25 hr, then increasing in concentration over the next 48 hr, though remaining significantly hypoosmotic to the blood. Adaptation to a salinity of 37‰ took 24 hr: the urine became almost isosmotic with the blood: the gastric and rectal fluids became hyperosmotic to the blood. Blood freezing-point determinations showed that over the salinity range 20–37‰ the lobster is able to osmoregulate to a limited extent only towards the lower end of the range, being otherwise an "osmocon-former." Salt-loading experiments indicated that the excess salts were rapidly excreted into the gut. It is concluded that the antennal glands are at least partly responsible for elimination of excess water, but that the gut is the site of salt excretion, and that there is rapid adjustment of salt imbalance.

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Some Effects of Salinity on the Survival, Moulting, and Growth ofCorophium Volutator[Amphipoda]

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400035220 ◽

1967 ◽

Vol 47 (3) ◽

pp. 607-617 ◽

Cited By ~ 58

Author(s):

Donald S. Mclusky

Keyword(s):

Experimental Study ◽

Growth Rate ◽

Maximum Rate ◽

Freezing Point ◽

Salinity Range ◽

Substrate Selection ◽

Tolerance Range ◽

Muddy Sand ◽

Corophium Volutator ◽

Burrowing Behaviour

An experimental study of the effects of salinity on the mud-dwelling amphipod,Corophium volutator(Pallas), indicates that, if supplied with mud, it will survive the salinity range of 2.50 %0, and without mud the range 7.5-47–5 %0. Moulting occurred in salinities of 2.6–46 %0, but most frequently in the range 5–20 %0. Growth occurred at a maximum rate in 15.4 %0, and only slightly slower at 4.4 and 30.6 %0; but below 4.4 %0the growth rate was progressively reduced. Freezing point studies showC, volutatorto be a hyperosmotic regulator, having a tissue tolerance range of 13–50 %0. The importance of a supply of mud, and the significance of hyperosmotic regulation are briefly discussed.INTRODUCTIONThe amphipodCorophium volutator(Pallas) is an inhabitant of littoral muds, the populations often reaching high densities. It has been most commonly reported from shores of estuaries, although Zenkevitch (1963) has stated that it may also occur in muds submerged to a depth of 10 m. Segerstråle (1959) has summarized the data available on the occurrence and distribution ofC. volutator. Since that date, work has been done on substrate selection (Meadows 1964a–c), on burrowing behaviour (Meadows & Reid, 1966) and on rhythmical swimming activity under tidal control (Morgan, 1965). Many authors (Nicol, 1935; Thamdrup, 1935; Beanland, 1940; Spooner & Moore, 1940; Rees, 1940; Goodhart, 1941; Stopford, 1951; Rullier, 1959; Gee, 1961) have described the substrate in whichC. volutatoroccurs. They have agreed thatC. volutatoris found in mud or muddy sand, containing approximately 37 % silt or clay.

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Sublethal Effects of Petroleum Hydrocarbons on Adult American Lobsters (Homarus americanus)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f83-093 ◽

1983 ◽

Vol 40 (6) ◽

pp. 705-717 ◽

Cited By ~ 8

Author(s):

Jerry F. Payne ◽

J. Kiceniuk ◽

R. Misra ◽

Garth Fletcher ◽

R. Thompson

Keyword(s):

Amino Acid ◽

Petroleum Hydrocarbons ◽

Sublethal Effects ◽

Freezing Point ◽

Amino Nitrogen ◽

Biological Response ◽

Homarus Americanus ◽

Point Sources ◽

Monitoring Point ◽

Oil Exposure

A suite of 56 different parameters including biochemical, physiological, and morphological indices were investigated in lobsters chronically exposed to a low level of petroleum hydrocarbons. General condition indices were unaffected and no oil-induced differences were noted in serum values for most of the electrolytes, except calcium, which was elevated in both sexes. Serum freezing-point depression decreased in both sexes of the experimental group. Considering the four major serum parameters, protein, lipid, glucose, and amino nitrogen, oil exposure had a significant effect on plasma protein and lipid values in the females. Chronic exposure to oil also had a marked impact on blood hemocytes in which lipid values were reduced by approximately one-half in both sexes. Three different types of oil-induced effects were noted for the essential amino acids, including (a) change in one sex only, (b) change in both sexes, and (c) interaction between sex and oil exposure. The only nonessential amino acid significantly affected by oil exposure was alanine. The differences observed in amino acid analogs, namely the elevation of serum levels of methionine sulfoxide and methylhistidine, have been discussed on the basis of mammalian studies as possible stress-related effects. One of the most interesting effects observed at the organismal level was gill browning, which markedly increased in the oil-exposed animals. This particular sublethal effect, possibly more than any other, could be considered pathological in nature. Gill browning is readily measurable and provides one suitable biological response for monitoring point sources of petroleum pollution in lobster habitats.

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Salt excretion in the Australian pipit, Anthus novaeseelandiae (Aves : Motacillidae)

Australian Journal of Zoology ◽

10.1071/zo9700373 ◽

1970 ◽

Vol 18 (4) ◽

pp. 373 ◽

Cited By ~ 1

Author(s):

D Rounsevell

Keyword(s):

Inorganic Ions ◽

Nasal Secretion ◽

Sodium Ions ◽

Salt Loading ◽

Salt Excretion ◽

Nasal Glands

Salt loading and treatment with cortisol did not induce nasal secretion of inorganic ions in pipits, and the structure of the glands did not appear to change after three consecutive days of the treatment. Salt loading did show that pipits could excrete urine containing sodium ions at NaCl concentrations of up to 570 m-equiv/l. It is concluded that the nasal glands in A. novaeseelandiae are not important in the excretion of electrolytes.

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Salinity tolerance and osmoregulation of Taeniomembers microstomus (Gunther, 1861) (Pisces: Mugiliformes: Atherinidae) from Australian salt lakes

Marine and Freshwater Research ◽

10.1071/mf9690157 ◽

1969 ◽

Vol 20 (2) ◽

pp. 157 ◽

Cited By ~ 21

Author(s):

LC Lui

Keyword(s):

Salinity Tolerance ◽

Body Fluid ◽

Freezing Point ◽

Probit Analysis ◽

Salt Lakes ◽

Salinity Range ◽

Freezing Point Depression

Salinity tolerance and osmoregulation of a population of Taeniomembras microstomus were studied. Results indicated that this atherinid fish is extremely euryhaline. Probit analysis revealed that the upper and lower L.D.50 values for salinity were 108‰ and 3.3‰, respectively. Salinity tolerance was apparently independent of acclimation, Taeniomembras microstomus has remarkable hypo-osmoregulatory abilities. The freezing point depression of body fluid varied from 0.558� to 2.729� when fish were exposed to a salinity range of 5-120‰.

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THE INFLUENCE OF LESIONS IN THE POSTEROVENTRAL GREY MATTER OF THE MID-BRAINS OF RATS ON SALT EXCRETION

Journal of Endocrinology ◽

10.1677/joe.0.0500123 ◽

1971 ◽

Vol 50 (1) ◽

pp. 123-133

Author(s):

H. L. GWYNNE ◽

MARY F. LOCKETT ◽

J. F. MARWOOD

Keyword(s):

Growth Hormone ◽

Thyroid Function ◽

Grey Matter ◽

Salt Balance ◽

Salt Loading ◽

Behavioural Changes ◽

Salt Excretion ◽

Normal Speed

SUMMARY Lesions in the posteroventral grey matter of the mid-brain reduced the ability of rats to excrete single oral saline loads and to adapt at normal speed to salt loading. Rats with these lesions had normal adrenal and thyroid function but stores of growth hormone in the adenohypophysis were reduced. Typical behavioural changes were induced: these included hyperactivity, almost frenzied blind running when disturbed which converted to perimeter running when obstructed by any object; hyperphagia and obesity. Effects on ability to handle salt loads are attributed to section of fibres ascending to the diencephalic centre in the posterior nuclei of the hypothalamus which influences salt balance.

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Transmission electron microscope studies in special ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108489 ◽

1978 ◽

Vol 36 (1) ◽

pp. 268-269

Author(s):

A. Zangvil ◽

L.J. Gauckler ◽

G. Schneider ◽

M. Rühle

Keyword(s):

Phase Diagrams ◽

Crystal Structures ◽

Thin Foil ◽

Limited Extent ◽

Complex Materials ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Electron Microscopes ◽

Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

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Effects of compression during formation on the microstructure of composite hydroxylapatite/plaster implants for bone reconstruction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105813 ◽

1988 ◽

Vol 46 ◽

pp. 750-751

Author(s):

J. Hanker ◽

K. Cowden ◽

R. Noecker ◽

P. Yates ◽

N. Georgiade ◽

...

Keyword(s):

Cosmetic Surgery ◽

Glass Plate ◽

Surgical Reconstruction ◽

Equal Weight ◽

Sintered Ceramic ◽

Setting Times ◽

Excess Water ◽

Mixture Prior ◽

Mechanical Strengths ◽

Calcium Sulfate Hemihydrate

Composites of plaster of Paris (PP) and hydroxylapatite (HA) particles are being applied for the surgical reconstruction of craniofacial bone defects and for cosmetic surgery. Two types of HA particles are being employed, the dense sintered ceramic (DHA) and the porous, coralline hydroxylapatite (PHA) particles. Excess water is expressed out of the moistened HA/PP mixture prior to implantation and setting by pressing it in a non-tapered syringe against a glass plate. This results in implants with faster setting times and greater mechanical strengths. It was therefore of interest to compare samples of the compressed versus noncompressed mixtures to see whether or not any changes in their microstructure after setting could be related to these different properties.USG Medical Grade Calcium Sulfate Hemihydrate (which has the lowest mortar consistency of any known plaster) was mixed with an equal weight of Interpore 200 particles (a commercial form of PHA). After moistening with a minimum amount of water, disc-shaped noncompressed samples were made by filling small holes (0.339 in. diameter x 0.053 in. deep) in polypropylene molds with a microspatula.

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HVEM Cryomicroscopy of Frozen Hydrated PTK1 Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181257 ◽

1990 ◽

Vol 48 (1) ◽

pp. 500-501

Author(s):

E.T. O’Toole ◽

G.P. Wray ◽

J.R. Kremer ◽

J.R. Mcintosh

Keyword(s):

Liquid Nitrogen ◽

Phase Contrast ◽

Culture Medium ◽

Low Dose ◽

Ammonium Acetate ◽

Freezing Point ◽

Voltage Electron ◽

Cold Stage ◽

Humidity Chamber ◽

Coated Carbon

Ultrarapid freezing and cryomicroscopy of frozen hydrated material makes it possible to visualize samples that have never been exposed to chemical fixatives, dehydration, or stains. In principle, freezing and cryoimaging methods avoid artifacts associated with chemical fixation and processing and allow one to visualize the specimen in a condition that is close to its native state. Here we describe a way to use a high voltage electron microscope (HVEM) for the cryoimaging of frozen hydrated PTK1 cells.PTK1 cells were cultured on formvar-coated, carbon stabilized gold grids. After three days in culture, the grids were removed from the culture medium and blotted in a humidity chamber at 35° C. In some instances, the grids were rinsed briefly in 0.16 M ammonium acetate buffer (pH 7.2) prior to blotting. After blotting, the grids were transferred to a plunging apparatus and plunged into liquid ethane held directly above its freezing point. The plunging apparatus consists of a vertical slide rail that guides the fall of a mounted pair of forceps that clamp the specimen. The forceps are surrounded by a plexiglass humidity chamber mounted over a dewar of liquid nitrogen containing an ethane chamber. After freezing, the samples were transferred to liquid nitrogen and viewed in a JEOL JEM 1000 equipped with a top entry cold stage designed and built by Mr. George Wray (Univ. Colorado). The samples were routinely exposed to electron doses of 1 e/Å2/sec, and viewed at a temperature of −150° C. A GATAN video system was used to enhance contrast and to estimate the correct amount of underfocus needed to obtain phase contrast at various magnifications. Low dose micrographs were taken using two second exposures of Kodak 4463 film. The state of the solid water in the specimen was determined by diffraction using a 30/μm field limiting aperture and a camera length of 1 meter.

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The influence of different types of milking units on milk quality and safety

145 - Tehnologìâ virobnictva ì pererobki produktìv tvarinnictva ◽

10.33245/2310-9289-2019-147-1-118-125 ◽

2019 ◽

pp. 118-125

Author(s):

A. Vovkohon ◽

V. Nadtochiy ◽

G. Kalinina ◽

O. Hrebelnyk ◽

N. Fedoruk ◽

...

Keyword(s):

Mass Fraction ◽

Dry Matter ◽

Freezing Point ◽

Titratable Acidity ◽

Petri Dish ◽

Milk Quality ◽

Quality And Safety ◽

Protein Mass ◽

Seeding Method ◽

Conductivity Increase

The article highlights comparative research results of milk quality indices obtained from the milking in specialized milking halls with such milking units as «Parallel», «Carousel» or in stalls with the milking unit «Molokoprovid». The fat and protein mass fraction, dry matter and fat-free dry matter, density, titratable and active acidity, heat resistance and freezing point have been determined according to the accepted techniques. The electrical conductivity of milk has been determined by using the analytical device MD-20 MAS-D-TEC. The total amount of milk bacteria has been determined by reductase reduction test and by seeding method in Petri dish. The milk quality has been investigated by the fermentation and rennet fermentation tests. The higher indices of the fat mass fraction, the protein mass fraction and the dry substance concentration of milk, obtained in specialized milking halls, have been established. This is not statistically significant. Milk, obtained from the milking unit «Molokoprovid», has higher index of titratable acidity, lower thermal stability in comparison with milk, obtained from specialized milking halls with milking units «Parallel» and «Carousel». It has been determined that there is the bacteria insemination increase in milk received from milking cows in stalls in comparison with milk, obtained from milking in specialized halls. Milk, obtained from the milking unit «Carousel», indicates the subclinical form of mastitis in cows or «Carousel» operation violationif there is in 1,8 mS/cm conductivity increase above average index 4,6 mS/cm. Key words: technology, quality and safety of milk, milking, milking unit, milking hall, bacterial insemination.

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