SEEDING DENSITY OF DIFFERENT FISH SPECIES IN POLYCULTURE

2017 ◽  
pp. 74-79
Author(s):  
Yuriy Borisovich Lvov
Keyword(s):  
Fish Species ◽  
Silver Carp ◽  
Seeding Density ◽  
Habitat Conditions ◽  
Method Of Calculation ◽  
Fish Breeding ◽  
Trophic Preferences ◽  
Breeding Zone ◽  
Practical Progress

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.

Results of a comparative study of the use of fodder worms of two breeds for pool growing of young tilapy and clary catfish in the conditions of the Almaty

2020 ◽  
pp. 73-80
Author(s):  
Z. Bolatbekova ◽  
S. Assylbekova ◽  
B. Kulatayev ◽  
S. Koishybayeva ◽  
N. Bulavina
Keyword(s):  
Comparative Study ◽  
Biochemical Composition ◽  
Nutritional Value ◽  
Fish Farming ◽  
Biological Indicators ◽  
Comprehensive Analysis ◽  
Fish Feed ◽  
Fish Breeding ◽  
Breeding Zone ◽  
Improved Methods

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.

scholarly journals Characteristics of Liparis loeselii (L.) Rich. populations in selected Natura 2000 areas in eastern Poland

2020 ◽  
Vol 55 (3) ◽  
pp. 151-162
Author(s):  
Danuta Urban ◽  
Joanna Sender ◽  
Ewelina Tokarz ◽  
Andrzej Różycki
Keyword(s):  
Natura 2000 ◽  
Total Carbon ◽  
Habitat Conditions ◽  
Total Carbon Content ◽  
Poor Fen ◽  
Calcareous Fen ◽  
Liparis Loeselii ◽  
The Individual ◽  
Insight Into

AbstractIn view of the sensitivity of Liparis loeselii to changes in habitat conditions, we carried out a study with the aim to monitor population numbers, identify the individual features of the Liparis loeselii population, analyse habitat conditions, identify threats and propose conservation measures to preserve the species. The investigations were conducted in seven unmanaged objects located in three Natura 2000 areas in eastern Poland. The results of this study provide a new insight into Liparis loeselii ecology. The analysed populations inhabited some habitat types: extremely poor fen, transitional mire, rich fen, calcareous fen, spring-fed fen. The content of nutrients was similar in all the habitats. A CCA analysis revealed that the total carbon content, pH, and redox potential of the substrate determine differences between the habitats analysed. Juvenile individuals represented a maximum of 12% of the analysed populations and were the least abundant group of these plants. The flowering was primarily influenced by hydrological conditions. Based on the long-term observations reported in this article, it can be assumed that the species stands a chance of surviving at the localities analysed, provided that the habitat conditions do not change dramatically.

Analysis of SINR for Unitary and Non-Unitary Precoded MIMO Systems

2011 ◽  
Vol 460-461 ◽  
pp. 414-419
Author(s):  
Xin Lu ◽  
Xiong Xu ◽  
Jian Hu Wang
Keyword(s):  
Computational Complexity ◽  
Mimo Systems ◽  
Original Method ◽  
Coding System ◽  
Simple Method ◽  
Method Of Calculation ◽  
Term Evolution ◽  
3Gpp Long Term Evolution ◽  
Output Sinr

Pre-coding type can be grouped into two approaches, unitary or non-unitary for 3GPP Long Term Evolution(LTE). Output SINR of unitary Pre-coding for MU-MIMO is investigated in this paper. A more simple method of calculation for SINR is presented, which Leads to the computational complexity down to 18% compared with original method, while calculating MIMO Pre-coding system with 4 matrices (i.e. 8 vectors). In addition, we also analyzed the loss of SINR when using unitary or non-unitary Pre-coding. Corresponding simulations show that output SINR of non-unitary pre-coding system is inferior to the unitary pre-coding case and such losses can been described using statistical linear approximation.

Modelling the effects of establishing a marine reserve for mobile fish species

2002 ◽  
Vol 59 (3) ◽  
pp. 405-415 ◽  
Author(s):  
P Apostolaki ◽  
E J Milner-Gulland ◽  
M K McAllister ◽  
G P Kirkwood
Keyword(s):  
Fish Species ◽  
Marine Reserve ◽  
High Mobility ◽  
Merluccius Merluccius ◽  
Seasonal Movements ◽  
Stock Biomass ◽  
Spawning Stock ◽  
Short And Long Term ◽  
Immature Fish

We present a model of the effects of a marine reserve on spawning stock biomass (SSB) and short- and long-term yield for a size-structured species that exhibits seasonal movements. The model considers the effects of protecting nursery and (or) spawning grounds under a range of fishing mortalities and fish mobility rates. We consider two extremes of effort redistribution following reserve establishment and analyze the effects of a reserve when the fishery targets either mature or immature fish. We apply the model to the Mediterranean hake (Merluccius merluccius) and show that a marine reserve could be highly beneficial for this species. We demonstrate benefits from reserves not just for overexploited stocks of low-mobility species, but also (to a lesser extent) for underexploited stocks and high-mobility species. Greatly increased resilience to overfishing is also found in the majority of cases. We show that a reserve provides benefits additional to those obtained from simple effort control. Benefits from reserves depend to a major extent on the amount of effort redistribution following reserve establishment and on fishing selectivity; hence, these factors should be key components of any evaluation of reserve effectiveness.

The issue of assessment of efficiency of works on land reclamation fisheries in inland waters of Russia

2021 ◽  
pp. 8-20
Author(s):  
Andrey Dmitrievich Bykov ◽  
Svetlana Yuryevna Brazhnik
Keyword(s):  
Fish Species ◽  
Land Reclamation ◽  
Long Term Results ◽  
Predatory Fish ◽  
Federal State ◽  
Inland Waters ◽  
Ecological Group ◽  
Spawning Grounds ◽  
Commercial Fish

The article considers the issue of assessing the long-term results of work on fisheries reclamation in inland waters of fisheries significance in Russia, carried out by the branches of the Federal State Budgetary Institution “Glavrybvod” on the state task in terms of their effectiveness. The relationship between dredging and clearing of watercourse beds and the dynamics of the number of producers of semi-navigable and non-aquatic fish in these rivers during spawning migrations has not been established. With long-term mowing of wetland vegetation in the shallow waters of reservoirs, deltas of large rivers and estuaries, there is no increase in their commercial fish productivity. A number of examples show the opposite effect of this type of work, which leads to a local deterioration of the ecological state of these reservoirs. At the same time, the repeatedly proven method of combating higher aquatic vegetation in the reservoirs of the south of Russia in low water conditions as biomelioration, based on the introduction of fish, consumers of autotrophic products by regional branches of the Federal State Budgetary Institution “Glavrybvod” is practically not used. When installing artificial spawning grounds in the littoral zone of reservoirs, regular ichthyological monitoring of the effectiveness of spawning on them is not carried out. There are no reliable data confirming the significant positive impact of artificial spawning grounds on the population dynamics of commercial fish species of the limnophilic ecological group under conditions of significant spring water level depletion in Russian reservoirs. When catching predatory and low-value fish species in water bodies, legal obstacles arise due to the fact that the volume of seizure of predatory fish includes commercial objects for which the ODE is established annually and their catch is already carried out according to industrial quotas.

scholarly journals Bioproductivity of ponds of VI fish breeding zone

2019 ◽  
Vol 2019 (4) ◽  
pp. 87-94
Author(s):  
Lina Yurievna Lagutkina ◽  
Evgeniia Kuzmina ◽  
Maria Georgievna Biryukova ◽  
Elena Pershina
Keyword(s):  
Limited Area ◽  
Freshwater Shrimps ◽  
Fish Breeding ◽  
Close Study ◽  
Nutritional Needs ◽  
Cultivated Species ◽  
Breeding Zone ◽  
Forage Base ◽  
Zooplankton Consumption ◽  
The Individual

Abstract. The paper highlights the prospects of cultivating heat-loving species, such as Australian crayfish and freshwater shrimps in the VI fish breeding zone. Australian crayfish and freshwater shrimps breeding is considered economically attractive for entrepreneurs, having a limited area for farming facilities. At the same time, pond ecosystems require the individual approach and close study in terms of the environmental conditions for the cultivated species upkeeping and the natural forage base that determine the pond biological productivity. Today, there are no clear recommendations on the summer keeping warmwater aquaculture species, in particular, Australian crayfish and freshwater shrimp in the Astrakhan region. To cultivate the new objects of warmwater aquaculture in 2017-2019 the small innovative enterprise Modern Sharapovskiy Fish Breeding Complex researched the production potential of ponds of various categories for receiving marketable products; there was studied the forage base, biomass of zooplankton and zoobenthos satisfying the nutritional needs of farmed objects. As a result of experimental work, it was found that in pond No.2, where freshwater shrimps were grown, there were registered 5 species of Cladocera and 1species of Rotifera, while in pond No.1 used for breeding Australian crayfish there were registered 4 species of Rotifera and only 1 species of Cladocera. Presumably, the observed species composition of the studied ponds is specified by the selectivity of the cultivated objects in zooplankton consumption. The possibility of increasing the bio-productivity of ponds by alternate growing aquaculture and agricultural products has been considered.

Change in the rocky reef fish fauna of the iconic Poor Knights Islands Marine Reserve in north-eastern New Zealand over 4 decades

2018 ◽  
Vol 69 (10) ◽  
pp. 1496
Author(s):  
David R. Schiel ◽  
Tony Ayling ◽  
Michael J. Kingsford ◽  
Christopher N. Battershill ◽  
J. Howard Choat ◽  
...  
Keyword(s):  
Reef Fish ◽  
Fish Species ◽  
Marine Reserve ◽  
Fish Fauna ◽  
Rocky Reef ◽  
Long Term Effects ◽  
Before And After ◽  
Negative Effect ◽  
Reef Fish Species

Marine reserves exhibit increases in targeted fish species, but long-term effects on biodiversity are poorly understood. Factors other than reserve status may affect decadal changes, including environmental change. We examined the fish fauna at the iconic Poor Knights Islands over 4 decades (1974–2016) before and after implementation of a no-take marine reserve in 1998. We document a substantial increase in commercially and recreationally targeted Chrysophrys auratus, which was virtually absent before 1994 but by 2016 had reached up to 11 fish per 500m2 (220 per hectare). There were also large changes to the fish community, including the decline of subtropical and coastal wrasses, some species with no change and others that increased significantly. Many declines occurred >20 years before the arrival of abundant C. auratus, suggesting the changes do not represent a trophic cascade. Furthermore, this normally benthic-feeding fish has adopted a mid-water foraging behaviour targeting planktivorous fish. The increase in C. auratus appears to be linked both to reserve status and catch regulations in the wider region. Overall, the data point to long-term environmental fluctuations from the late 1970s having a negative effect on the abundance of more than half the reef fish species at these islands.

Polyculture in fish farming as a method of preventing fish diseases

2021 ◽  
pp. 30-40
Author(s):  
Grigory Emelyanovich Servetnik
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Fish Farming ◽  
Natural Food ◽  
Total Biomass ◽  
Fish Farms ◽  
Fish Diseases ◽  
Host Body ◽  
Contagious Diseases

Methods of prevention of fish diseases are aimed at destroying parasites in the host body and in the fish habitat — in the reservoir (chemoprophylaxis, increasing fish resistance), at preventing parasites from entering the reservoir (limiting the import of fish, import of healthy fish, quarantine measures, etc.), as well as preventing their spread and entry into the host body. It is shown that polyculture is not only the most effective method of using the natural forage base of the reservoir and, as a result, increasing fish productivity, but also a means of preventing mass infectious and other fish diseases. To prevent mass infectious diseases of fish and death from them both in safe and unfavorable ponds of carp fish farms, it is advisable to grow other fish species together with carp that do not suffer from diseases peculiar to carp. As a result, so-called sparse species plantings of fish are created in the ponds, while the total biomass remains high. At the same time, the natural food supply of ponds is most fully used and a kind of biological buffer is created that prevents the emergence and spread of contagious diseases. Polyculture can play a particularly important role in pond farms that already have certain problems with rubella, filometroidosis, botryocephalosis, carp pox, etc. Long-term studies of breeding herds in pond farms have shown that most of them have single foci of diseases, which, if there are optimal conditions for the pathogen, are ready to immediately respond with an outbreak of the disease or are generally quarantined for a particular fish disease. When determining the objects of polyculture, it is necessary to reduce the proportion of fish species that have a significant number of common diseases.

Sign in / Sign up

Export Citation Format

Share Document