scholarly journals On the issue of Australian crayfish cultivation in ponds to ensure sustainable aquaculture development

2021 ◽  
Vol 937 (3) ◽  
pp. 032030
Author(s):  
Lina Lagutkina ◽  
Polina Rozhkova ◽  
Elena Evgrafova ◽  
Yulia Grozesku ◽  
Sergey Ponomarev ◽  
...  

Abstract The authors of this article describe the experience of biotechnology for growing Australian crayfish in conditions of pond cultivation in a group of ponds, operating in an intensive mode, used in an isolated area close by a natural water source in the Astrakhan region. In the presented article, research is aimed to clarify the main biotechnological indicators that increase the efficiency of cultivation in pond conditions. The conditions of transportation, the duration of transportation, and the density of crayfish in ponds with an area of 1 hectare have been clarified. The presented food recipe with the specification of the percentage of nutrients as additional feeding, organized when growing in ponds according to the food recipe itself, increases not only the growth rate but also the hemolymph protein concentration, which indirectly proves the satisfactory conditions for keeping aquaculture objects. Monitoring for the biotechnology of growing Australian crayfish in pond conditions: own developed food recipe, biological and physiological testing of key indicators such as hydrochemical indicators of water, hydrobiological indicators of the concentration of, and physiological indicators for determining the so-called biotechnological norm, which will add additional missing information on this aquaculture object.

1987 ◽  
Vol 44 (11) ◽  
pp. 1995-2001 ◽  
Author(s):  
Stephen H. Bowen

It is widely believed that fishes require more dietary protein than other vertebrates. Many aspects of fish physiology, nutrition, and trophic ecology have been interpreted within the context of this high protein requirement. Here, fishes are compared with terrestrial homeotherms in terms of (1) protein requirement for maintenance, (2) relative protein concentration in the diet required for maximum growth rate, (3) protein intake rate required for maximum growth rate, (4) efficiency of protein retention in growth, and (5) weight of growth achieved per weight of protein ingested. The two animal groups compared differ only in relative protein concentration in the diet required for maximum growth rate. This difference is explained in terms of homeotherms' greater requirement for energy and does not reflect absolute differences in protein requirement. The remaining measures of protein requirement suggest that fishes and terrestrial homeotherms are remarkably similar in their use of protein as a nutritional resource. Reinterpretation of the role of protein in fish physiology, nutrition, and trophic ecology is perhaps in order.


2020 ◽  
Author(s):  
Katja Pulkkinen ◽  
Tarmo Ketola ◽  
Jouni Laakso ◽  
Johanna Mappes ◽  
Lotta-Riina Sundberg

SummaryPhenotypic variation allows adaptation of opportunistic pathogens to variable conditions in the outside-host environment with strong effects on their epidemiology and pathogenicity in hosts. Here we found that the isolates of an opportunistic fish pathogen Flavobacterium columnare from fish farming environment had higher phenotypic variation between two morphotypes in growth, as compared to the isolates from the natural water environment. The rough morphotypes had higher growth rate than the rhizoid morphotypes especially in the higher resource concentrations and in the higher temperature, but only if the isolate was originating from the fish farms. Rhizoid morphotype was more virulent than the rough type regardless of their origin. However, the virulence of the rough type increased sharply with the size of the fish, and the bacterial isolates from the gills of diseased fish were rhizoid type, indicating a reversal of the rough morphotype into rhizoid in contact with the fish. The high growth rate of the rough morphotype combined with the morphotype reversibility could increase the probability of columnaris epidemics at fish farms. Our findings suggest that intensive farming imposes different selection pressures on bacterial survival in the outside-host environment and its transmission compared to the natural water environment.


2020 ◽  
pp. 70-77
Author(s):  
L.A. Deryabkina ◽  
◽  
B.I. Marchenko ◽  
N.K. Plugotarenko ◽  
A.I. Yukhno ◽  
...  

In most Russian regions there is still a pressing issue related to providing population with high quality and safe drinking water. Up to now, chlorination has been the primary technique applied to disinfect drinking water as it is highly efficient, reliable, and relatively cheap. However, when chlorine is used to disinfect natural water that contains organic pollutants, it results in risks of by-products occurrence. These products are trihalomethanes, epigenetic carcinogenesis promoters that cause elevated carcinogenic risks under oral, inhalation, and subcutaneous exposure. Our research goal was to hygienically assess efficiency of pre-ammonization applied in water treatment procedures in order to prevent occurrence of carcinogenic organic chlorine compounds during chlorination and to minimize carcinogenic risks. We determined trihalomethanes and residual chlorine contents in model samples of natural water taken from a surface water source after chlorination with different doses of chlorine. We examined 52 pair parallel samples that had undergone pre-ammonization with ammonia sulfate and control ones. Trihalomethanes concentrations were determined in model water samples with gas-liquid chromatography. Basing on the results obtained via experiments on laboratory chlorination of river water, we determined quantitative characteristics and built regression models showing dependence between concentrations of organic chlorine compounds occurring due to chlorination (chloroform, dichlorobrommethane, dibromchloromethane) and chlorine doses and preammonization parameters. It was established that pre-ammonization was the most efficient in terms of preventing trihalomethanes occurrence under such disinfection modes when contents of residual active chlorine didn’t exceed recommended levels (0.8–1.2 mg/L). Basic ways to minimize carcinogenic risks caused by trihalomethanes are systemic control over their contents in drinking water during social and hygienic monitoring procedures; preliminary ammonization of water taken from surface water sources; prevention of unjustified hyper-chlorination; preliminary deep purification of initial water; disinfection with ultrasound radiation instead of preliminary chlorination; etc.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2630
Author(s):  
Sebastián Crespo ◽  
Céline Lavergne ◽  
Francisco Fernandoy ◽  
Ariel Muñoz ◽  
Leandro Cara ◽  
...  

The Aconcagua river basin (Chile, 32 °S) has suffered the effects of the megadrought over the last decade. The severe snowfall deficiency drastically modified the water supply to the catchment headwaters. Despite the recognized snowmelt contribution to the basin, an unknown streamflow buffering effect is produced by glacial, periglacial and groundwater inputs, especially in dry periods. Hence, each type of water source was characterized and quantified for each season, through the combination of stable isotope and ionic analyses as natural water tracers. The δ18O and electric conductivity were identified as the key parameters for the differentiation of each water source. The use of these parameters in the stable isotope mixing “simmr” model revealed that snowmelt input accounted 52% in spring and only 22–36% during the rest of the year in the headwaters. While glacial supply contributed up to 34%, both groundwater and periglacial exhibited a remarkable contribution around 20% with some seasonal variations. Downstream, glacial contribution averaged 15–20%, groundwater seasonally increased up to 46%, and periglacial input was surprisingly high (i.e., 14–21%). The different water sources contribution quantification over time for the Aconcagua River reported in this work provides key information for water security in this territory.


1988 ◽  
Vol 59 (1) ◽  
pp. 141-147 ◽  
Author(s):  
R. Ballard ◽  
R. G. Bardsley ◽  
P. J. Buttery

1. Two experiments are reported in which the effect of alteration in growth rate on the levels of avian skeletal muscle calcium-activated neutral proteinase (EC 3.4.22. 17) (CANP or calpain) and its specific inhibitor (calpastatin), a system thought to be implicated in myofibrillar catabolism, was studied by means of manipulation of dietary protein concentration.2. In Expt 1 broiler chicks were given free access to diets containing 105, 149, 197 and 212 g protein/kg for 20 d. In Expt 2 the four dietary treatments were 119, 141, 182 and 227 g protein/kg diet given for 16 d. Chick growth rate and total leg skeletal muscle weight significantly increased (P < 0·001) with increasing dietary protein concentration in both experiments. Total skeletal muscle protein increased with the level of dietary protein, the effect being significant (P < 0·01 and P < 0·001 in Expts 1 and 2 respectively).3. Minced leg muscle was homogenized in low-salt buffers, and the extract chromatographed on DEAE-cellulose to separate proteinase and inhibitor activity. The partially purified CANP enzyme and inhibitor proteins were present at a concentration broadly consistent with literature reports, and their elution characteristics and Ca2+ concentration dependence were not varied by dietary protein concentration.4. Both the muscle CANP and CANP inhibitor activities (units/kg muscle) exhibited upward trends with growth rate and increased muscle weight. However, these differences were not statistically significant (P > 0·05) and were not present at all when the results were expressed as units/g muscle protein.


1976 ◽  
Vol 86 (1) ◽  
pp. 7-16 ◽  
Author(s):  
M. F. Fuller ◽  
P. R. English ◽  
R. M. Livingstone ◽  
R. M. J. Crofts

SUMMARYDiets containing 10·5, 13, 15·5 or 18% protein were formulated by progressively replacing barley by a 2:1 mixture of soya-bean meal and fish meal. Each diet was given at three levels of intake proportional to (body weight) 0·73. A total of 144 pigs were used at two centres.Growth rate increased with food intake at each protein level, but to the greatest extent with the 13% crude protein (CP) diet. Growth rate also increased with protein level; the results suggested that there would be no further improvement above 18% CP. The effects of protein concentrationon food conversion generally reflected those on daily gain.Carcass fatness, estimated by both midline and introscope measurements of fat thickness and by specific gravity, increased significantly with the intake of all but the 18% protein diet. When theeffects of food intake were taken into account, carcass fatness increased steadily with reductions in protein level down to 13%; the reduction from 13 to 10·5% produced a much greaterincrease in fatness.The reductions in daily food intake necessary to achieve equal carcass fatness as protein level wasreduced were of the order of 0·1 kg per 1% CP from 18% to 13% CP, but ofthe order of 0·3 kg per 1% CP below 13%.Differences between the sexes were greatest at high protein concentration; significant differences between the centres were found only with the low protein diets.


1990 ◽  
Vol 51 (1) ◽  
pp. 189-199 ◽  
Author(s):  
I. Kyriazakis ◽  
G. C. Emmans ◽  
C. T. Whittemore

ABSTRACTTo test the proposition that growing pigs, when given a choice between two foods, are able to select a diet that meets their requirements, and to investigate the rules of diet selection, four foods (L, A, B and H) with similar energy yields, but different concentrations of crude protein (CP) (125, 174, 213 and 267 g CP per kg fresh food respectively) were formulated. The four foods were offeredad libitumeither singly, or as a two-way choice using all the six possible pairs, to 40 individually caged pigs from 12 to 30 kg live weight. On the single foods the rate of food intake fell from 1001 to 971 to 961 to 868 (s.e.d. 40) g/day (F < 0·05) as the protein concentration of the foods increased from L to H; the growth rate followed an opposite trend (492, 627, 743 and 693 (s.e.d. 31) g/day respectively;P< 0·01). When the pigs had to select between two foods limiting in protein (L and A) the less limiting one was preferred (710 (s.e. 200) g A per kg total food intake; the protein concentration of the selected diet was 160 (s.e. 10) g CP per kg). On the choice between B and H (a choice between a food with protein concentration close to requirements and a food with protein excess) the lower food was markedly preferred (928 (s.e. 4) g B per kg total food intake; the protein concentration of the selected diet was 218 (s.e. 1) g CP per kg). When the animals were given a choice between two foods, a combination of which was non-limiting (pairs LB, LH, AB and AH), the protein concentrations of the selected diets were not different between treatments (208, 204, 202 and 205 (s.e.d. 13) g CP per kg respectively) and they also declined systematically with time and weight. The growth rate of the animals on these pairs were 752, 768, 769 and 763 (s.e.d. 54) g/day (P > 0·05), which were not significantly different from the highest growth rate achieved on a single food. The results suggest that pigs, when given a choice between a suitable pair of foods, are able to choose a balanced diet and to change its composition to reflect their changing requirements. The choice-feeding method may well be useful as an effective and economic way of estimating and meeting requirements, and of measuring the growth potential of pigs.


1977 ◽  
Vol 55 (3) ◽  
pp. 543-552 ◽  
Author(s):  
F. Paré ◽  
L. Huot ◽  
J. M. Perron ◽  
M. Cloutier

Total protein contents of the hemolymph of Choristoneura fumiferana larvae, prepupae, and pupae were studied. These were electrophoretically separated into 14 bands, classified as slow moving and fast moving proteins. During the sixth instar, hemolymph protein contents increased eight to nine times in control larvae mainly owing to slow moving proteins. Protein concentration of slow moving proteins were less pronounced in larvae that were starved and treated with Bacillus thuringiensis, the treated larvae being more affected than the starved larvae. Larvae treated on day 1 of the 6th instar were more affected than those treated on day 4.


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