Nitrogenous Excretion of Amphipods and Isopods

1950 ◽  
Vol 27 (2) ◽  
pp. 210-225
Author(s):  
ELISABETH I. B. DRESEL ◽  
VIVIEN MOYLE
Keyword(s):  
Uric Acid ◽  
Nitrogen Metabolism ◽  
Fresh Water ◽  
Gammarus Pulex ◽  
Nitrogen Excretion ◽  
Physiological Adaptation ◽  
Asellus Aquaticus ◽  
Terrestrial Species ◽  
Water Species ◽  
Eleven Species

1. The nitrogen excretion of eleven species of amphipods and isopods, including marine, fresh-water and terrestrial forms, has been studied. 2. All species are essentially ammonotelic, since more than 50% of the total soluble N.P.N. of the excreta was present in the form of ammonia throughout. 3. The level of nitrogen excretion is appreciably lower in the terrestrial species than in any of the others, indicating that, in this group, adaptation to terrestrial conditions has been attended by a general suppression of nitrogen metabolism rather than by a transformation of ammonia to other, less toxic products. 4. Some 5-10% of the total soluble N.P.N. was present as urea in the case of the fresh-water amphipod, Gammarus pulex, and as uric acid in the terrestrial isopods as well as the fresh-water isopod, Asellus aquaticus. It is suggested that these minor excretory components might originate from purines as a result of the loss of one or more of the uricolytic enzymes. 5. In association with the excretion of uric acid some retention of this insoluble compound usually occurs, and it was found that among the terrestrial species the amount so stored parallels the degree of morphological and physiological adaptation to terrestrial conditions. The greatest accumulation of uric acid was, however, observed in the fresh-water species, A. aquaticus, and although such a storage cannot necessarily be taken as evidence for a partially uricogenic metabolism, this possibility must be borne in mind.

Nitrogen Excretion in Developing Chick Embryos

Development ◽  
1957 ◽  
Vol 5 (3) ◽  
pp. 215-224
Author(s):  
James R. Fisher ◽  
Robert E. Eakin
Keyword(s):  
Uric Acid ◽  
Experimental Evidence ◽  
Nitrogen Metabolism ◽  
Metabolic Changes ◽  
Nitrogen Excretion ◽  
Chick Embryos ◽  
The Many

Of the many examples of metabolic changes occurring during development, the most widely cited is that in developing chicks wherein the end product of nitrogen metabolism has been assumed to shift from ammonia to urea and finally to uric acid (Needham, 1931). This system appeared to be ideal for a proposed study of the mechanisms bringing about such changes in metabolism, providing the occurrence of these changes could be further substantiated. The experimental evidence upon which this pattern had been postulated consisted entirely of measurements of the total amounts of ammonia, urea, and uric acid in the allantois and the ratio of their total weights to the weight of the embryo. Nothing was reported concerning the changes in concentration of these substances nor their presence outside the allantois. Lack of this information makes it impossible to conclude that net synthesis occurs, particularly in the cases of ammonia and urea where the total amounts present are quite small.

scholarly journals Nitrogenous metabolism in Thoroughbred and Arabian foals from birth to five months of age

2006 ◽  
Vol 58 (4) ◽  
pp. 525-529 ◽  
Author(s):  
G. Piccione ◽  
A. Costa ◽  
F. Fazio ◽  
F. Grasso ◽  
G. Caola
Keyword(s):  
Uric Acid ◽  
Serum Concentration ◽  
Nitrogen Metabolism ◽  
Rectal Temperature ◽  
Total Protein ◽  
Critical Period ◽  
Critical Period Of Development ◽  
Over Time ◽  
Time Point ◽  
Nitrogenous Metabolism

The maturation of nitrogen metabolism was studied in six Thoroughbred and six Arabian foals. Rectal temperature, heart and respiratory rates and serum concentration of several hematochemical parameters (total protein, urea, uric acid, creatinine, and albumine) were monitored from birth to 5 months of age. In both breeds, all the parameters except albumine showed significant differences over time (P<0.05). The two breeds did not differ from each other at any time point. Statistically significant decreases in urea and creatinine concentrations were related to the growth needs of foals during this critical period of development.

Nitrogen Excretion in Ascidiacea II. Storage Excretion and the Uricolytic Enzyme System

1965 ◽  
Vol 42 (2) ◽  
pp. 299-305
Author(s):  
IVAN GOODBODY
Keyword(s):  
Uric Acid ◽  
Calcium Carbonate ◽  
Protein Metabolism ◽  
Enzyme System ◽  
Purine Metabolism ◽  
Nitrogen Excretion ◽  
Purine Base ◽  
Purine Bases ◽  
Ascidiella Aspersa

1. The evidence for the occurrence of storage excretion in ascidians is reviewed. Most species probably store uric acid or purine bases in some form. 2. The renal concretions of Ascidia nigra and Phallusia mammillata contain 50-60% uric acid, the remainder of the concretion is unidentified but is non-nitrogenous and is not calcium carbonate. In Ascidiella aspersa the concretion is predominantly composed of calcium carbonate and there is no significant quantity of uric acid or purine base. 3. Uric acid is also identified in Molgula manhattensis, Polycarpa obtecta, Pyura vittata and Herdmania momus. 4. Storage excretion probably results from a deficiency in the uricolytic enzyme system. It is concluded that while protein metabolism is ammonotelic, purine metabolism is uricotelic or xanthotelic.

Nitrogen excretion in germ-free and conventional chickens: effects of an alkali load

1978 ◽  
Vol 39 (1) ◽  
pp. 99-104 ◽  
Author(s):  
J. Okumura ◽  
D. Hewitt ◽  
Marie E. Coates
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Ammonia Excretion ◽  
Nitrogen Excretion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Total N ◽  
Germ Free ◽  
Base Balance ◽  
Micro Organisms

1. Groups of three colostomized germ-free (GF) and conventional (CV) chickens aged 4 months were maintained for successive periods of 8 d on a diet containing 200 g casein/kg without and with sodium bicarbonate at the rate of 20 mmol/d and a nitrogen-free diet without and with NaHCO3at 9 mmol/d. Urine and faeces were collected during the last 3 d of each period.2. Total N, uric acid- and ammonia-N were determined in urine and total N in faeces. Amino acids were measured in hydrolysates of faeces collected during the periods when no NaHCO3was included in the diets.3. The CV birds excreted more N on the casein diets but less on the N-free diets than did their GF counterparts, the differences being mainly shown in the urine.4. On both diets hydrolysates of the faeces of CV birds contained smaller amounts of amino acids. On the N-free diet the proportions (g/160 g N) of serine, proline and threonine were reduced, suggesting some conservation of endogenous N by micro-organisms, and the proportions of histidine, alanine, lysine and methionine increased, possibly through microbial synthesis; on the casein diet, proportions of most amino acids were less, probably because bacterial deamination had occurred.5. Urinary excretion of total N, uric acid and ammonia was much greater on the casein than on the N-free diets. Inclusion of NaHCO3caused a sharp fall in urinary ammonia on both diets and in both environments.6. It was concluded that the level of dietary protein and the regulation of acid-base balance have more effect than microbial activity on the urinary ammonia excretion.

scholarly journals The Distribution of Gammarus Species in Estuaries. Part I

1947 ◽  
Vol 27 (1) ◽  
pp. 1-52 ◽  
Author(s):  
G. M. Spooner
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Field Work ◽  
Bottom Fauna ◽  
Qualitative Composition ◽  
British Isles ◽  
Free Swimming ◽  
The Status ◽  
Brackish Water Species ◽  
Water Species

The work of which an account is here given was largely carried out from the autumn of 1937 to the spring of 1940, when it was interrupted by the war. In taking it up again (in July 1945) while, facilities for field work are still limited, the author feels it useful to publish results as they stand and indicate where further work is considered advisable.In examinations of the free-swimming bottom fauna of the Tamar and other estuaries, attention was inevitably drawn to the populations of Gammarus species, which make up the greater bulk of it. Before quantitative observations were planned, some interesting points came to light with regard to the qualitative composition of populations. This aspect lent itself more readily to study and, though byno means a new field for exploration, soon proved worth examining ingreater detail than previous workers had attempted.The broad fact of a replacement of one Gammarus species by another in passing up an estuary was well enough known, though exact knowledge for the British Isles only starts from the time when G. zaddachi Sexton was recognized as a regular member of the upper estuarine fauna of the Tay (Bassindale, 1933; Alexander, Southgate & Bassindale, 1935) and of the Deben (Serventy, 1935). This species proved to be the main brackish-water species overlapping with the marine G. locusta (L.) near the seaward end, and with the fresh-water G. pulex (L.) at the river end (or ‘head’) of the estuary. The status in estuaries of two other brackish-water species, G. duebeni Lillj. and G. chevreuxi Sexton, remained obscure.

scholarly journals Dietary Preference ofGammarus pulexandAsellus aquaticusduring a Laboratory Breeding Programme for Ecotoxicological Studies

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
M. C. Bloor
Keyword(s):  
Food Preference ◽  
Alnus Glutinosa ◽  
Gammarus Pulex ◽  
The Other ◽  
Ex Situ ◽  
Breeding Programme ◽  
Asellus Aquaticus ◽  
Leaf Material ◽  
Dietary Preference ◽  
Laboratory Breeding

An investigation was undertaken to establish ifGammarus pulexandAsellus aquaticuspreferred a diet of unconditioned, artificially or naturally conditioned alder leaves (Alnus glutinosa). Standardised, 24 hourex situfeeding assays were undertaken with both species to determine their food preference. The results showed thatA. aquaticusate more leaf material compared toG. pulex(Z 23.909,P0.001) when exposed to all three test variables. Also, bothG. pulexandA. aquaticusdemonstrated a preference for naturally conditioned leaves compared to the other two variables, with unconditioned leaves proving the least popular food option for both macroinvertebrates (Z 18.803, ). However, both species ate varying amounts of all the leaf treatments (Z 136.399, ). Subsequently, the author outlined a feeding methodology for natural alder leaf conditioning that could be used during a laboratory breeding programme.

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