Cage fish culture in lakes of Pokhara Valley, Nepal.

2020 ◽  
Author(s):  
Madhav Shrestha
Keyword(s):  
Silver Carp ◽  
Water Bodies ◽  
Bighead Carp ◽  
Ctenopharyngodon Idella ◽  
Small Scale ◽  
Hypophthalmichthys Molitrix ◽  
Support Programme ◽  
Steady Rate ◽  
Cage Aquaculture ◽  
Pokhara Valley

Abstract Pokhara valley is situated at the southwestern part of Kaski district in west Nepal. Although the valley is comprised of eight large and small lakes, cage culture is predominant in Begnas, Phewa and Rupa Lakes. A vulnerable fisher community known as pode or jalari living around the lakes of Pokhara Valley is among several ethnic groups whose livelihood is entirely dependent on fishing in these water bodies. A livelihood support programme for rehabilitation through creation of employment and income generation for this deprived community through subsistence cage aquaculture was initiated in 1972 in the lakes of the valley. Since then cage aquaculture has grown at a steady rate and at present 21,650 m3 of cages exist in these water bodies which produced an estimated 88.4 t of fish in 2004 to support the livelihoods of the 109 fisher families. Floating cages using four bamboo poles in a square as a float are popular in the fishers group. Mainly two species of carp are popular for culture in cages: bighead carp (Aristichthys nobilis) and silver carp (Hypophthalmichthys molitrix). Occasionally, other species are also stocked with bighead and silver carp such as rohu (Labeo rohita) as a biological cleaning agent to reduce fouling of the cage. The grass carp (Ctenopharyngodon idella) is also cultured in Lake Phewa on a small scale and is fed with grass. Average production of cages in Begnas, Phewa and Rupa Lakes is 3, 4.2 and 3.2 kg m-3 year-1, respectively.

Modern features of aquaculture of cyprinids in the republic of Iraq

2020 ◽  
pp. 6-14
Author(s):  
Farhan Yasin Hamed ◽  
Adelia Zakirovna Anokhina ◽  
Natalia Viktorovna Sudakova ◽  
Damelya Kazhigalievna Magzanova
Keyword(s):  
Silver Carp ◽  
Stocking Density ◽  
Fish Farming ◽  
Pond Water ◽  
Government Support ◽  
Bighead Carp ◽  
Ctenopharyngodon Idella ◽  
Natural Food ◽  
Hypophthalmichthys Molitrix ◽  
Fish Farms

It is shown that the leading role in the aquaculture of Iraq belongs to Cyprinids, which account for over 80 % of all fish farming production. The most widespread in the country are four main world species of carp aquaculture: common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). Basically, the traditional technology of growing Cyprinids in ponds is used, which includes the main fish farming processes: care of broodstock to prepare them for spawning, collecting eggs and milt, eggs fertilization and incubation of embryos, raising juveniles and marketable fish. Currently, there are about 2 thousand private fish farms, which have ponds of various sizes from 4 to 100 hectares. Cultivation of Cyprinids in Iraq is carried out mainly by extensive methods: the use of the natural food base of reservoirs with low fish stocking density in polyculture. The fish productivity of ponds varies greatly in different fish farms from 1,5 to 6 t/ha, which is due to economic reasons. The data on changes in the temperature of pond water during the year and hydrochemical indicators are given, which shows favorable conditions for Cyprinids rearing. Information on the use of compound feeds for growing carp in ponds is provided, and data on the composition and nutritional value of the feed used. The fish culture indicators for the main biotechnical processes of the rearing of four Cyprinid species in Iraq are described in detail. In the conclusion, it is indicated that for the effective development of aquaculture in Iraq, government support is needed in the form of a developed long-term program and legislative acts.

scholarly journals Status of Chinese Carp Fisheries in Tunisian Freshwater Reservoirs: Threats and Opportunities

2021 ◽  
Vol 2 (10) ◽  
pp. 945-953
Author(s):  
Sami Mili ◽  
Rim Ennouri ◽  
Manel Fatnassi ◽  
Tahani Chargui ◽  
Hajer Zarrouk ◽  
...  
Keyword(s):  
Native Species ◽  
Aquatic Vegetation ◽  
Silver Carp ◽  
Bighead Carp ◽  
Ctenopharyngodon Idella ◽  
Hypophthalmichthys Molitrix ◽  
Artificial Breeding ◽  
Canal Systems ◽  
The Impact ◽  
Technical Centre

The current paper aims to diagnose the state of fisheries of three Chinese carp species whish have been introduced in Tunisian reservoirs since 1981: (silver carp Hypophthalmichthys molitrix, herbivorous carp Ctenopharyngodon idella and bighead carp Aristichthys nobilis) and seeks to study the benefits and risks associated with their introduction. Chinese carps cannot reproduce naturally in freshwater reservoirs. Eventually, artificial breeding operations and seeding of the dams with farm-produced fry are carried out by the Technical Centre of Aquaculture every year. Statistical analyses have shown a strong correlation between the landed quantity and the number of fries stocked each year. The impact assessment showed that the risks and benefits associated with the introduction of the three species are variable. Regarding their benefits, it was clear that the herbivorous carp has provided effective and sustainable control of the extensive development of aquatic vegetation in the eutrophic reservoirs and canal systems. The value of the other two species, though, remains less obvious, particularly for the bighead carp. The consequences of their introduction on ecosystems and native species seem to be negligible, especially when the densities are low. Eventually, it seems judicious to increase the stocking of the herbivorous carp, silver carp and bighead carp in Tunisian reservoirs.

scholarly journals Induced Breeding of Freshwater Fishes and Cost Benefit Analysis of a Selected Fish Hatchery in Jashore, Bangladesh

2021 ◽  
pp. 15-25
Author(s):  
Anusree Biswas ◽  
Moumita Choudhury ◽  
Md. Almamun Farid ◽  
M. Aminur Rahman ◽  
M. Anisur Rahman
Keyword(s):  
Cost Benefit Analysis ◽  
Silver Carp ◽  
Cost Benefit ◽  
Bighead Carp ◽  
Ctenopharyngodon Idella ◽  
Catla Catla ◽  
Benefit Analysis ◽  
Hypophthalmichthys Molitrix ◽  
Fish Hatchery ◽  
Breeding Techniques

An investigation was carried out to know the induced breeding techniques of some firewater fish species such as rui (Labeo rohita), catla (Catla catla), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio), bighead carp (Hypophthalmichthys nobilis), sharpunti (Puntius sarana) and bata (Labeo bata) at Ma Fatima Fish Hatchery in Chanchra, Jashore, Bangladesh. The cost-benefit analysis was also performed on this hatchery for three months from May to July, 2016. The brood fishes purchased from different local sources were used for spawning. The hatchery mainly practiced induced breeding by maintaining proper age and weight of brood stock during spawning. The ranges of fertilization and hatching rates of the experimental fishes were 80.04±1.44 % to 94.35±0.54% and 75.34±3.49% to 88.68±2.76%, respectively. Total spawn production was 960, 862 and 734 kg, and the total revenue income from spawn sell was BDT 2,883,500, 2,355,100 and 1,844,800 (BDT 85 = 1 US$) in May, June and July, respectively. Estimated capital cost was BDT 87,90,000, while the operating costs were BDT 1,810,650; 1,555,105 and 1,267,680 in May, June and July, respectively. The calculated cost-benefit ratios in May, June and July were 1.59, 1.51 and 1.46, respectively. The hatchery got the highest net profit of BDT (Bangladeshi Taka) 1,041,906 in May due to the highest production and higher price of spawn, and the lowest profit of BDT 546,176 was obtained in July. So, May was found to be the peak breeding month of Ma Fatima Hatchery. The estimated cost-benefit ratio indicated that the spawn production through induced breeding techniques was profitable for the hatchery owners.

scholarly journals Hydrology controls recruitment of two invasive cyprinids: bigheaded carp reproduction in a navigable large river

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3641 ◽  
Author(s):  
Daniel K. Gibson-Reinemer ◽  
Levi E. Solomon ◽  
Richard M. Pendleton ◽  
John H. Chick ◽  
Andrew F. Casper
Keyword(s):  
Mississippi River ◽  
Silver Carp ◽  
Monitoring Program ◽  
Large River ◽  
Asian Carp ◽  
Bighead Carp ◽  
Illinois River ◽  
Hypophthalmichthys Molitrix ◽  
The Past ◽  
Causative Factors

In the Mississippi River Basin of North America, invasive bigheaded carp (silver carpHypophthalmichthys molitrixand bighead carpH. nobilis, also referred to as Asian carp) have spread rapidly over the past several decades. In the Illinois River, an important tributary of the Upper Mississippi River, reproduction appears to be sporadic and frequently unsuccessful, yet bigheaded carp densities in this river are among the highest recorded on the continent. Understanding the causative factors behind erratic recruitment in this commercially-harvested invasive species is important for both limiting their spread and managing their harvest. We analyzed weekly catch records from 15 years of a standardized monitoring program to document the emergence of age-0 bigheaded carp in relation to environmental conditions. The appearance of age-0 fish was generally linked to hydrographic attributes, which probably serve as a cue for spawning. However, we found profound differences in the number of age-0 fish among years, which varied by as much as five orders of magnitude in successive years. The strong link between summer flooding and age-0 fish production we observed emphasizes the importance of understanding the hydrologic context in which sustained invasions occur. Despite evidence of sporadic recruitment, bigheaded carp populations in the Illinois River appear to be consistent or increasing because of particularly strong, episodic year classes.

Invasive Asian Carps in North America

2011 ◽  
Keyword(s):  
Great Lakes ◽  
Mississippi River ◽  
Silver Carp ◽  
Bighead Carp ◽  
Ctenopharyngodon Idella ◽  
Great Lakes Basin ◽  
Black Carp ◽  
Federal Department ◽  
In The Wild ◽  
Asian Carps

<em>Abstract</em>.—There are four species collectively known as the Asian carps: grass carp <em>Ctenopharyngodon idella</em>, bighead carp <em>Hypophthalmichthys nobilis</em>, silver carp <em>H. molitrix</em>, and black carp <em>Mylopharyngodon piceus</em>. These species have been introduced worldwide for aquaculture purposes. Subsequent to introduction into the southern United States, three species have become well-established in the wild (grass, bighead, and silver carps). Two of these species, bighead and silver carps, have been dispersing rapidly up the Mississippi River basin, wreaking ecological havoc along the way. As there are numerous connections between the Mississippi basin and Canadian watersheds, including the Great Lakes, there is considerable concern about their potential ecological impacts if introduced and established in Canada. In addition to natural dispersal, these species may also be introduced into the Canadian wild through the live food fish trade. In 2004, the Canadian federal department of Fisheries and Oceans Canada conducted a risk assessment to determine the ecological risk of Asian carps to Canada. This assessment included evaluating the risk of survival, reproduction and spread of these species, as well as their pathogens, parasites, or fellow travelers (e.g. other invasive species), should they be introduced into Canada. These components were assessed in an expert workshop using best available information on their biology, potential vectors of introduction, and impacts in both native and introduced ranges. The assessment concluded that the risk of impact was high in, at least, some parts of Canada, including the southern Great Lakes basin by all four Asian carp species.

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