Vast fish breeding colony is more than twice the size of Paris

Nature ◽  
2022 ◽  
Yuriy Borisovich Lvov

The article touches upon the principles, biological basics and practical progress of introduction of specific and age polyculture of fishes. Using the results of the analysis of literary and long-term native data, there has been offered the gradation of 12 fish species from different families by resistance to habitat conditions. Crucian ( Carassius gibelio ) has been chosen as the most sustainable object of cultivation. There has been taken an attempt to calculate the number of seeding different fish species in polyculture taking into account their physiological features is made. Subject to specific physiological features of the studied species, there was carried out recalculation of their natural reproductive performance in different fish-breeding zones, which is traditionally carried out for a carp ( Cyprinus carpio ). In particular, in the second fish-breeding zone with area of 1 hectare it is possible to breed 120 kg of carp, or 150 kg of crucian, or 75 kg of silver carp ( Hypophthalmichthys ). Overall productivity is made up of a share of fishes in polyculture, but taking into account tolerance of species, it can be lower than productivity calculated for carp. The method of calculation and formulas which give the chance to determine seeding density of fish species for breeding in polyculture have been offered. This technique makes it possible to use trophic preferences and consider tolerance of each species to the conditions of breeding areas.

Ekaterina Grinberg

In two parts of the article, more than 70 errors and violations of the Biotechnics of artificial breeding of Pacific salmon in salmon hatcheries are collected and summarized, which lead to an immediate or delayed deterioration of the quality of reared fry and a decrease in their survival rate. Deviations from the biological basis of fish farming are shown and possible consequences of such errors or violations are predicted. In the first part of the article (#7,2020) there were General errors (throughout the entire fish-breeding process), as well as violations of Biotechnics during the work with producers, collecting eggs and preparing them for incubation, in the second part-violations of Biotechnics during the incubation of eggs, holding pre-larvae, rearing and release of young. Their correction, prevention or minimization of consequences will significantly improve the quality of sexual products and offspring from producers, increase the linear and weight gain of juveniles during rearing, improve the coefficient of feed payment, reduce the time of rearing, improve the epizootic situation by developing immunity in fry and mobilizing other protective reactions of their body, significantly reduce waste at all stages of the production process, increasing survival by 10–15%. In conclusion, it is noted that the first and most important condition for an efficient salmon hatchery is the creation of optimal environmental conditions at each stage of the production process. The second condition is strict compliance with the Biotechnics of artificial salmon breeding and the complex of veterinary and sanitary, fish-breeding and meliorative and therapeutic and preventive measures. The third is the availability of competent specialists who regularly improve their skills in accredited Universities to implement, control and manage the first two conditions.

Z. Bolatbekova ◽  
S. Assylbekova ◽  
B. Kulatayev ◽  
S. Koishybayeva ◽  
N. Bulavina

The aryicle presents the results of a comparative study of the biochemical composition of earthworms of dendrobene and prospector rocks, the peculiarities of their cultivation and their use for feeding when growing juvenile tilapia and clary catfish. The experience of cultivating earthworms of two breeds using the improved methods of foreign authors is described. The results of a study of the biochemical composition of cultivated objects that determine their nutritional value for feeding fish are presented. The fish-breeding and biological indicators of juvenile tilapia and clary catfish, obtained during the cultivation of dendrobene and prospector in fish farming in the Almaty region (VI fish-breeding zone) during worm feeding, are analyzed. A comprehensive analysis of the studied indicators made it possible to assign a certain rating place to each worm breed in relation to its use as fish feed.

2001 ◽  
Vol 35 (2) ◽  
pp. 140-146 ◽  
R. H. Foote ◽  
E. Hare

Rabbit seminal plasma catalase is much higher than in the semen of other mammals, and differences appear to be inherited. Because of the scarcity of information on rabbit blood catalase and haematocrit in Dutch-belted rabbits, an investigation of possible effects of gender, age and genetics on these variables was undertaken. There were 191 rabbits sampled at 2-3 months, 130 at 12 months and 61 at 18-24 months of age. There was no age effect on the haematocrit values and on blood catalase activity. At 12 months of age males had an average haematocrit value of 44% compared with 40% for females ( P < 0.05). Corresponding average catalase values were 431 and 356 units/ml of blood ( P < 0.05). Also catalase was measured in the semen and blood of 34 males, and males differed in both their blood and semen catalase activity ( P < 0.05). The correlation between the two traits was r = 0.44. Heritability ( h2) estimates, based on 231 rabbits were 0.40 for blood catalase activity, and 0.26 for haematocrit. The genetic correlation between the two variables was 0.83 ( P < 0.05). These studies are consistent with the literature in that female rabbits have a slightly lower haematocrit value than males, and this is associated with a lower catalase activity. This appears to be the first report of a study that compares rabbit blood catalase in males and females of different ages. Preliminary evidence that differences may have a heritable basis is consistent with previous studies on rabbit semen catalase.

2021 ◽  
David A. Ehlers Smith ◽  
Brent Coverdale ◽  
Ben Hoffman ◽  
Christopher Kelly ◽  
Yvette C. Ehlers Smith ◽  

1972 ◽  
Vol 1 (1) ◽  
pp. 3-28 ◽  
G. Van Wagenen

2016 ◽  
Vol 27 (1) ◽  
pp. 140-152 ◽  

SummaryThe number of vultures is declining in many parts of the world due to numerous threats, such as poisoning and collisions with power-lines as well as the lack of adequate food sources. Vulture restaurants, i.e. supplementary feeding stations, have become a widespread conservation tool aimed at supporting vulture colonies. However, it is poorly understood how vulture restaurants influence population dynamics and whether they affect breeding success of vulture populations. We used a 12-year dataset from a breeding colony of the Cape Vulture Gyps coprotheres and a nearby vulture restaurant in South Africa to investigate the effect of supplementary food on population dynamics and breeding success. We found a significantly positive effect of supplementary food during the nest-building stage on the number of breeding pairs. However, breeding success, i.e. the proportion of successful nests, did not depend on supplementary food during the incubation and rearing stage. Especially during the critical rearing stage, the amount of food supplied might not have been sufficient to meet food demands of the colony. Still, our results indicate that carefully managed vulture restaurants might stabilise vulture colonies and can therefore aid vulture conservation.

2010 ◽  
Vol 139 (2) ◽  
pp. 362-381 ◽  
Christina J. Maranto ◽  
Thomas P. Good ◽  
Francis K. Wiese ◽  
Julia K. Parrish

Aquaculture ◽  
2011 ◽  
Vol 311 (1-4) ◽  
pp. 110-114 ◽  
Anders Skaarud ◽  
John Arthur Woolliams ◽  
Hans Magnus Gjøen

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