Trigger mechanism of increased urea production by the crayfish, Orconectes rusticus under osmotic stress

Sharma, Moti L.

doi:10.1016/0010-406x(69)90813-5

Cited by 13 publications

(5 citation statements)

References 13 publications

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“…Certain authors have reported greater proportions of amino acids in excreted nitrogen, 2 0 % in Copepods (Johannes & Webb, 1965;Webb & Johannes, 1967 and 10-25 o/ o in Euphausiids (Jawed, I 969). The high urea excretion reported for the crayfish Orconectes rusticus (Sharma, 1966(Sharma, , 1968(Sharma, , 1969 or the specific uric acid excretion of the land crab Cardisoma guanhumi (Gifford, 1-2 1968) seem to be exceptions to the rule rather than a general feature. Indeed, more recent studies suggest that amino-acid excretion is rather low, especially in Natantia.…”

Section: End-products Of Nitrogen Metabolismmentioning

confidence: 92%

“…According to Sharma (1969), the shift to ureotelism would result from an increase of inorganic ions in the internal medium. Sharma (1966) did not observe any significant change in the ammonia excretion rate of a crayfish after acclimation to 50 yo sea water.…”

Section: (B) Salinitymentioning

confidence: 99%

“…However, in some terrestrial Isopods, ammonia can diffuse from the body in the gaseous form (Wieser, Schweizer & Hartenstein, 1969). Ammonia makes up from 70% to 87% of the total excreted nitrogen in marine (Corner & Newell, 1967) and Tigriopus brevicornis (Harris, 1973), 72 yo in the spiny 1obsterJasus edwardsi (Binns & Peterson, 1969), 86 in the crab Carcinus maenas (Needham, 1957) and around 95% in the shrimps Palaemonetes varians (Snow & Williams, 1971) and Crangon crangon (Regnault, (Sharma, 1966(Sharma, , 1968(Sharma, , 1969 or the specific uric acid excretion of the land crab Cardisoma guanhumi (Gifford, 1-2 1968) seem to be exceptions to the rule rather than a general feature. However, recent observations by Quarmby (1985) on the shrimp Pandalus platyceros suggest that we re-examine the question.…”

Section: End-products Of Nitrogen Metabolismmentioning

confidence: 99%

“…So the author concluded that a 'shift' from ammonotelism to ureotelism had occurred. According to Sharma (1969), the shift to ureotelism would result from an increase of inorganic ions in the internal medium. A similar shift was reported by Krishnamoorthy & Srihari (1973) for the fresh-water crab Paratelphusa hydrodromus after acclimation to sea water.…”

Section: (B) Salinitymentioning

confidence: 99%

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Nitrogen Excretion in Marine and Fresh‐water Crustacea

1987

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Summary 1. The major characteristic of aquatic Crustacea is ammonotelism as shown by the relative importance of various nitrogenous end‐products of their nitrogen metabolism. 2. In contrast to urico‐ and ureo‐genesis pathways, ammoniogenesis pathways have received recent attention; some specific enzymes such as glutamate dehydrogenase, AMP‐deaminase and glutaminase are now admitted to play a possible key role in ammoniogenesis of various crustacean species. 3. Processes involved in ammonia output through the gill epithelium (diffusion and/or ionic exchanges) are discussed though few data related to Crustacea are as yet available compared to those obtained in ammonotelic fishes. 4. The effects of some environmental factors as well as the physiological state of animals on nitrogen excretion of Crustacea are envisaged. The effects of temperature, salinity and NH4 concentration in the external medium are discussed first, followed by the changes in nitrogen excretion associated with the moult cycle, the nutritional state of animals and possible neuroendocrine control. It is demonstrated that the response of the excretion rate to these factors presents various patterns according to the species, its osmoregulatory abilities and its body reserves. Changes can also occur in the requisite metabolic pathways, thus increasing the difficulty of generalization. 5. In spite of the great diversity encountered within Crustacea an attempt to bring out general trends of their nitrogen excretion is proposed. 6. The present review is focused on metabolic and physiological aspects of crustacean nitrogen excretion but the significance of nitrogen release in nutrient regeneration in marine and fresh‐water ecosystems is foreseen.

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Section: End-products Of Nitrogen Metabolismmentioning

confidence: 92%

Section: (B) Salinitymentioning

confidence: 99%

Section: End-products Of Nitrogen Metabolismmentioning

confidence: 99%

Section: (B) Salinitymentioning

confidence: 99%

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Nitrogen Excretion in Marine and Fresh‐water Crustacea

1987

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“…start to degrade soft tissues and produce microbial enzymes, such as ureases and proteases and the bacterial metabolism switches to decomposition of amino acids and urea, leading to an increase of the pH value and an alkalization of the carcass (Skopp, 2010;Socks-Fischer et al, 1999). Urea is present in the haemolymph of crayfish as a detoxification product (Sharma, 1969) and is hydrolysed to ammonia and carbamate, which spontaneously decompose into a second molecule of ammonia and carbonic acid. In water, the products react to bicarbonate, ammonium and hydroxide ions, which results in an increase of the pH value.…”

Section: Figurementioning

confidence: 99%

Calcite precipitation forms crystal clusters and muscle mineralization during the decomposition of Cambarellus diminutus (Decapoda: Cambaridae) in freshwater

Mähler¹,

Janssen²,

Menneken³

et al. 2020

Palaeontol Electron

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The fossilization of soft tissues is generally the replacement of organic structures by pseudomorphs in which muscle tissue is mostly replaced by minerals (i.e., phosphate, carbonate or pyrite). Micro-CT observations of decomposing crayfish in tank and distilled water, show a precipitation of crystal clusters over time. In addition, a mineralized muscle was found by SEM analyses. Raman spectroscopy (CRS) revealed that crystal clusters and the muscle consist of well-ordered calcite. Inductively coupled plasma mass spectrometry (ICPMS) of the distilled water showed a calcium content below the detection limit at the beginning of the experiments, which indicates that most of the calcium ions needed for the precipitation were provided by the decomposing carcasses themselves. Volume measurements of 3D-reconstructed calcite clusters and gastroliths showed a general increase of the volume of calcite clusters and simultaneously volume reduction of gastroliths with progressive decay. Specimens that were in the postmoult phase showed a smaller total volume of precipitated calcite, compared to specimens, which were in the intermoult or premoult phase. In addition, measurements of the total amount of body calcium of Cambarellus diminutus by atomic absorption spectrophotometry (AAS) revealed a higher amount of calcium in individuals without gastroliths than in individuals with gastroliths. It is assumed, that the higher the body size, the higher the volume of precipitated calcite, if the individuals were in the intermoult phase at the time of death. If the individuals were in the postmoult or premoult phase, the phase itself seems to be important.

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A Functional Role for Amino Acids in the Adaptation of Tissues from the Nervous System to Alterations in Environmental Osmolality

Baxter

Baldwin

1978

Amino Acids as Chemical Transmitters

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Trigger mechanism of increased urea production by the crayfish, Orconectes rusticus under osmotic stress

Cited by 13 publications

References 13 publications

Nitrogen Excretion in Marine and Fresh‐water Crustacea

Nitrogen Excretion in Marine and Fresh‐water Crustacea

Calcite precipitation forms crystal clusters and muscle mineralization during the decomposition of Cambarellus diminutus (Decapoda: Cambaridae) in freshwater

A Functional Role for Amino Acids in the Adaptation of Tissues from the Nervous System to Alterations in Environmental Osmolality

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