Frm Flashcards
(135 cards)
1
Q
How long does it take to produce block ice using sodium or calcium chloride solution?
A
12-24 hours may be taken to produce ice.
2
Q
What is the advantage of modern rapid ice making systems?
A
Ice blocks are produced in a few hours by improving the manufacturing process.
3
Q
How are ice blocks formed in a rapid block ice plant?
A
Several tubes through which the refrigerant is passed are arranged in a tank of water.
4
Q
What happens as ice builds up in the rapid block ice plant?
A
It fuses with the ice on the adjacent tubes to form a block with a number of hollow cores.
5
Q
How are blocks released from the tubes in a rapid block ice plant?
A
Blocks are released from the tubes by a hot gas defrost.
6
Q
What is another method for producing block ice?
A
The refrigerant is circulated through a jacket around each can of water and through pipes running through the centre of the can.
7
Q
How are blocks removed in the second method of block ice production?
A
Blocks are removed by gravity after a hot gas defrost.
8
Q
What is flake ice?
A
Ice with smooth contours and in the shape of very thin flakes, usually 100 to 1000 mm² in area and 2-3 mm in thickness.
9
Q
Why is flake ice preferred over block ice?
A
Flake ice has a very high area per unit mass and can cover.
10
Q
What is the FAO definition of aquaculture?
A
Farming of Aquatic Organisms including fish, mollusks, crustaceans and aquatic plants.
Farming implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc.
11
Q
What are the two essential factors that differentiate aquaculture from capture fisheries?
A
- Intervention to enhance production
- Ownership of the stock
12
Q
List some activities considered as aquaculture.
A
- Rearing of fry, spat, post larvae in hatcheries
- Stocking of ponds, cages, tanks, raceways
- Culture in private tidal ponds
- Rearing molluscs to market size
- Stocked fish culture in paddy fields
- Harvesting planted or suspended seaweed
- Valliculture
13
Q
When did agriculture first develop and where?
A
Agriculture first developed 10,000 years ago in the Middle East.
14
Q
What were some early crops cultivated in agriculture?
A
- Wheat
- Barley
- Rice
- Sorghum
- Millet
- Maize
15
Q
When did common carp culture develop and where?
A
Common carp culture developed some hundreds of years BC in China.
16
Q
What are some aquatic parameters that affect aquatic organisms?
A
- Very low solubility of O2
- High solubility of CO2
- pH
- Salinity
- Buffering capacity
- Dissolved nutrients
- Toxic nitrogenous wastes
- Turbidity
- Heavy metals
- Photo and zooplankton concentration
- Current velocity
17
Q
True or False: Most aquaculture is based on domesticated species.
A
False
18
Q
Name a few fish species that have been domesticated for aquaculture.
A
- Common carp
- Atlantic salmon
- Rainbow trout
- Tilapia species
- Channel catfish
19
Q
What was the global aquaculture production in 2009?
A
55.7 million tons valued at 105.3 billion USD.
20
Q
What was the annual growth rate of aquaculture from 2001 to 2009?
A
6.1%
21
Q
Fill in the blank: Aquaculture production of plants in 2009 was ______.
A
17.3 million MT valued at 4.8 billion US dollars.
22
Q
Which region produced the highest percentage of total aquaculture production in 2008?
A
Asia produced 88.8% of the total aquaculture production by quantity.
23
Q
What percentage of world aquaculture production did China contribute in 2008?
A
62.3% by quantity and 51.4% by value.
24
Q
What environment dominated aquaculture production in 2009?
A
Freshwater environment.
25
What is the percentage contribution of carps to total world aquaculture production?
39.9%
26
List the types of freshwater resources.
* Surface waters
* Ground water
* Ice and glaciers
* Soil moisture
27
Name the top three countries with the highest percentage of freshwater resources.
* Brazil - 14.9%
* Russia - 8.1%
* Canada - 6.0%
28
What is the area of ponds and tanks suitable for fish culture in India?
2.25 million ha.
29
What percentage of ponds and tanks in India are currently utilized for fish culture?
45%
30
Name the three major Indian carps cultivated in freshwater aquaculture.
* Catla
* Rohu
* Mrigal
31
What are air breathing fishes and give examples.
Fish that can survive in poor water quality. Examples: Giant murrel, striped murrel, spotted murrel.
32
What is the contribution of carps to freshwater aquaculture production in India?
90%
33
Fill in the blank: Freshwater aquaculture accounts for ______ of the total inland production.
70%
34
What are nursery ponds?
Ponds where spawn are reared to fry stage.
35
What is the desirable pH range for pond soil?
6.5 – 7.00
36
What is the purpose of liming in pond management?
Improves the quality of the pond soil and enhances productivity.
37
What is the role of draining and drying in pre-stocking management?
Facilitates oxidation of organic matter, degassing of toxic gases, and kills pathogenic microorganisms.
38
What factors influence the productivity of fish ponds?
Factors include:
* Texture
* Water retention
* pH
* Organic carbon
* Available nitrogen
* Available phosphorous
## Footnote
These factors determine the soil quality and overall health of the pond ecosystem.
39
What is the desirable pH range for pond soil?
6.5 – 7.00
## Footnote
This pH range is optimal for enhancing fish productivity.
40
What materials are commonly used for liming in ponds?
Common liming materials include:
* Agricultural lime or calcite (CaCO3)
* Dolomite [CaMg(CO3)]
* Calcium hydroxide/slaked lime (Ca(OH)2)
* Calcium oxide/quicklime (CaO)
## Footnote
Liming materials help to improve soil quality and correct pH.
41
What is the typical application rate of lime to pond soil?
200-500 kg/ha
## Footnote
The dose varies based on the effectiveness of the lime and the soil pH.
42
What role does liming play in fish pond management?
Liming helps in:
* Correcting soil pH
* Mineralization of organic matter
* Release of soil-bound phosphorous to water
* Disinfection of the pond bottom
## Footnote
These factors contribute to improved water quality and fish health.
43
What is the primary food source for fry and fingerlings of most fish?
Zooplankton
## Footnote
Sustained zooplankton production relies on good phytoplankton and bacterial base.
44
Why is nutrient addition necessary in fish ponds?
Natural availability of nutrients is often inadequate, necessitating external sources for sustained plankton growth.
## Footnote
Key nutrients include nitrogen, phosphorus, carbon, and micronutrients.
45
What types of manures are commonly used in fish pond fertilization?
Common organic manures include:
* Cow dung
* Poultry litter
* Pig dung
* Horse dung
## Footnote
Cow dung and poultry manure are the most frequently used.
46
How is raw cow dung typically applied to fish ponds?
Applied at a rate of 5-10 tons/ha, generally 15 days before stocking
## Footnote
It can also be applied in phases for better nutrient release.
47
What are the characteristics of inorganic fertilizers used in fish ponds?
Inorganic fertilizers are:
* Concentrated forms of nutrients
* Promote phytoplankton production
* Require cautious use to avoid excessive algae blooms
## Footnote
Common sources include urea or ammonium sulfate for nitrogen and super phosphates for phosphorus.
48
What problems do aquatic weeds cause in fish ponds?
Aquatic weeds can:
* Compete for nutrients
* Prevent light penetration
* Cause oxygen fluctuations
* Harbor pests
* Hinder fish movement
* Cause harvesting issues
* Increase siltation
## Footnote
Effective management of aquatic weeds is essential for maintaining pond health.
49
What methods can be used to control aquatic weeds?
Methods include:
* Manual
* Mechanical
* Chemical
* Biological
## Footnote
The choice of method depends on pond size, extent of infestation, available time, and cost.
50
What are common predatory fish that threaten stocked fish?
Common predatory fish include:
* Murrels (Snakeheads)
* Catfishes (e.g., Wallago attu, Clarias batrachus)
* Heteropneustis fossilis
* Ompak sp.
## Footnote
These fish can significantly reduce the survival of stocked fish.
51
What is the most effective method for eradicating predatory and weed fish?
Dewatering followed by sun drying
## Footnote
In ponds that cannot be dewatered, piscicides are an alternative.
52
What characteristics should a suitable piscicide have?
A suitable piscicide should be:
* Effective at low doses
* Non-injurious to humans and animals
* Safe for human consumption of fish
* Quick to detoxify
* Economical
## Footnote
These characteristics ensure safe and effective use in aquaculture.
53
What is the active ingredient in Derris root powder used as a piscicide?
Rotenone
## Footnote
It acts as a contact poison lethal to various aquatic organisms.
54
What is the recommended dosage for Mahua oilcake as a piscicide?
250 ppm
## Footnote
This substance causes lysis of red blood cells and can affect multiple aquatic species.
55
What is the ideal stocking density for carp spawn in earthen nursery ponds?
300 to 500 numbers per m²
## Footnote
Stocking density varies based on management level.
56
What is the typical feeding rate for spawn in fish ponds?
8-10% of the biomass
## Footnote
Adjustments are made based on growth and biomass estimations.
57
What are the key water quality parameters for fish culture?
Key parameters include:
* Dissolved oxygen (should be above 5 mg/L)
* Ammonia levels
* Overall water quality
## Footnote
Maintaining these parameters is crucial for fish health and growth.
58
What is the significance of the family Cyprinidae in aquaculture?
It is the largest family of fish, with 1600 species, and includes major sources of animal protein, particularly carps
## Footnote
Only 29 species are cultured globally, with six being the most prominent.
59
What are the major Indian carps commonly cultured?
Major Indian carps include:
* Catla
* Rohu
* Mrigal
## Footnote
These species are significant for aquaculture in India.
60
What is the primary feeding habit of the Silver carp?
Zoo- and phytoplankton feeder, surface feeder
## Footnote
This species prefers phytoplankton and plays a crucial role in pond ecosystems.
61
What is polyculture in carp farming?
Polyculture is the farming of two or more compatible species with different feeding habits in the same pond
## Footnote
It maximizes resource utilization and enhances production.
62
How is the yield affected in polyculture systems compared to monoculture systems?
Production is generally higher in polyculture systems
## Footnote
This is due to better utilization of food and space.
63
What is the yield per hectare achieved in Indian composite polyculture systems?
Nearly 9 MT/ha/yr
## Footnote
This yield is achieved when ponds are fertilized and provided with supplementary feed.
64
What are the common supplementary feeds used in high stocking density fish farming?
Common supplementary feeds include:
* Mixture of rice bran or wheat bran
* Oil cakes (groundnut, mustard, cotton seed)
## Footnote
Additional ingredients like fish meal and vitamins can improve feed quality.
65
What is the ideal feeding rate for grow-out ponds?
Initial feeding rate is 5%, decreasing to 2-3% biomass until harvest
## Footnote
Regular biomass sampling is necessary to adjust feeding rates.
66
What is rohu known as in China?
Silver carp
## Footnote
Rohu is a significant species in Indian carp farming.
67
What species of Indian major carps are cultured in Andhra Pradesh?
Rohu and catla
## Footnote
Rohu is the dominant species in polyculture.
68
What is the stocking density of rohu in Andhra Pradesh ponds?
80%
## Footnote
Catla is stocked at 20%.
69
What is the average production of fish in Andhra Pradesh?
8000 kg/ha
## Footnote
The range is between 5300-14620 kg/ha.
70
What are the main stages of carp culture?
Nursery Phase, Rearing Phase, Grow-out Phase
## Footnote
Each phase has specific management practices.
71
What is the optimal stocking density for nursery ponds?
3-5 million/ha
## Footnote
Higher densities can be used in cement tanks.
72
What is the rearing period for carp fry in the nursery phase?
15-20 days
## Footnote
Fry are reared up to a size of 25mm.
73
What type of feed is given to carp fry in the nursery phase?
Finely powdered mixture of oilcake and rice bran in 1:1 ratio
## Footnote
This is supplemented with natural food.
74
How are fry harvested in the nursery phase?
By repeated dragging with a fry net of 1/8 inch mesh
## Footnote
Harvesting quantity is measured in perforated cups.
75
What is the survival rate of fry from June to September?
40-50%
## Footnote
2-3 crops of fry can be raised in earthen ponds.
76
What is the recommended stocking density for rearing carp fry to fingerling stage?
2-3 lakh/ha
## Footnote
Monoculture or polyculture can be followed.
77
What is the primary feed during the grow-out phase for carp?
Rice bran and oil cakes
## Footnote
This can be supplemented with fishmeal and soybean meal.
78
What is the average national carp culture productivity in India?
2 tons/ha/yr
## Footnote
The potential production is 3-4 tons under semi-intensive culture.
79
What is the recommended stocking density for grow-out ponds?
5000 fingerlings/ha
## Footnote
This can be raised to 8000-10,000 fingerlings/ha.
80
How long do carps take to reach marketable size?
10-12 months
## Footnote
This is when fingerlings of 8-10g are stocked.
81
What is the role of aquatic weeds in carp culture?
Provide shelter and aid in ecological balance
## Footnote
Grass carp should be stocked if terrestrial grasses are available.
82
What are the key aquatic insect control methods in carp nursery ponds?
Application of soap oil emulsion
## Footnote
This method effectively controls insect populations.
83
What is the importance of fingerling harvesting?
Essential for ensuring good quality seed production
## Footnote
Poor management can lead to low survival rates.
84
What should be done before stocking carp culture ponds?
Control aquatic weeds, eradicate predators, apply lime
## Footnote
This prepares the pond for optimal conditions.
85
How are fingerlings transported for long distances?
Packed in sealed polyethylene bags filled with water and pure oxygen
## Footnote
The ratio of water to oxygen is typically 1:2 to 1:3.
86
What is the survival rate of fingerlings with good management?
70-80%
## Footnote
This can vary based on conditions and practices.
87
What is the significance of catfish farming in India?
Identified as a national priority for aquaculture diversification
## Footnote
Includes both native and exotic species.
88
What type of feed is provided to fry in the initial stage?
Formulated crumbled feed pellets of 35% protein or a mixture of finely mined trash fish/molluscan meat and rice bran in a 1:1 ratio
## Footnote
The fry are fed at 5-10% of the biomass.
89
What is the size of fry after 30 days of growth?
3-4 cm (0.8-1g)
90
What is the stocking density for magur in grow-out culture?
50,000 – 70,000 fingerlings/ha
91
What type of feed is used for magur in grow-out culture?
Mixtures of groundnut oil cake, rice bran, fish meal/trash fish
## Footnote
Fed at 3-5% biomass.
92
How long does it take for magur to reach marketable size?
7-8 months
93
How is harvesting of magur typically conducted?
By draining the ponds and handpicking the fish.
94
What is the average production of magur from the grow-out culture system?
3-4 tons/ha/7-8 months
95
What is the common name of Heteropneustis fossilis?
Singhi
96
What are the optimal water conditions for singhi larvae?
DO: 5-6 ppm, pH: 6.5-7.5, Temperature: 26-28°C
97
What is the initial feed for singhi larvae?
Mixed zooplankton, Artemia nauplii, and tubifex worms
98
At what size are singhi stocked in small cement tanks?
12-15 mm
99
What is the estimated production potential of singhi?
4-15 tons/ha in 4-12 months
100
Name some other species of catfish mentioned.
* Pangasius sp.
* Wallago attu
* Ompak sp.
* Mystus sp.
* Rita rita
* Bagarius bagarius
101
What is the common name of Macrobrachium rosenbergii?
Giant freshwater prawn
102
What type of water do freshwater prawn larvae require?
Brackish water
103
What is the primary dietary behavior of freshwater prawns?
Omnivorous and cannibalistic
104
What is the main obstacle to freshwater prawn culture?
Size variation in the population
105
What are the three male morphotypes of Macrobrachium rosenbergii?
* Small male (SM)
* Orange claw male (OC)
* Blue claw male (BC)
106
What is the continuous system in prawn culture?
Regular stocking of post larvae and selective harvesting of prawns
107
What is the batch system in prawn culture?
Stocking the pond once and allowing individuals to grow to market size before total harvest
108
What does the combined system in prawn culture involve?
Stocking once, cull-harvesting fast-growing prawns, and final drain-harvesting
109
What is extensive prawn culture?
Rearing prawns in ponds with production less than 500 Kg/ha/yr
110
What defines semi-intensive prawn culture?
Stocking density of 4-20/m2, use of fertilization, and balanced feeds
111
What is an intensive prawn culture system characterized by?
High water exchange, continuous aeration, and stocking at 20/m2
112
What is the recommended lime application for pond preparation?
1000 kg/ha
113
What is the impact of introducing exotic species?
Depletion of biodiversity, endangering native species, introduction of new diseases
114
What is a significant case study of exotic species introduction?
Introduction of Nile perch in Lake Victoria led to extinction of endemic fish
115
What are some recommended measures to contain escapements of introduced species?
* Regular inspection of pond walls
* Secondary back-up containment facilities
* Predator deterrence
116
True or False: Freshwater ecosystems contain 40% of the total fish species on Earth.
True
117
What is the main concern regarding the introduction of Clarias gariepinus?
It is highly predatory and threatens native species.
118
What measures should be taken to contain escapements in aquaculture facilities?
Regular inspection of pond walls, secondary back-up containment facilities, predator deterrence, underwater predatory netting around net cages, site surveys prior to farm construction, and conducting fish handling operations within a controlled area.
## Footnote
Escapements refer to the unintended release of fish from aquaculture facilities.
119
What is sewage fed fish culture?
Fish production in ponds fertilized with waste water, common in some parts of Asia, perceived as more attractive than intensive farming.
## Footnote
Sewage fed aquaculture integrates fish culture technology with sanitation engineering.
120
What is the average net fish production from waste fed aquaculture in Germany?
500 kg/ha/7 months, with loading rates equivalent to waste water generated by 2000 persons/ha/yr.
## Footnote
The German system averages lower yields due to lower stocking densities compared to tropical systems.
121
What are the main fish species used in sewage fed aquaculture in Germany?
* Common carp (Cyprinus carpio)
* Tench (Tinca tinca)
## Footnote
These species are adapted to the conditions of the aquaculture system in Germany.
122
What was the production level achieved in the Indian Aquaculture Sewage Treatment Plant?
3-4 metric tons/ha/yr.
## Footnote
This was achieved using a combination of duckweed and fish culture.
123
What percentage of water does sewage typically contain?
90-99% water.
## Footnote
Sewage also contains organic matter, bacteria, and protozoa.
124
What are the common characteristics of sewage?
* Cloudy liquid
* Contains minerals and organic matter
* High BOD and COD
* Contains traces of heavy metals
## Footnote
BOD stands for Biochemical Oxygen Demand, and COD stands for Chemical Oxygen Demand.
125
What problems are associated with sewage fed culture systems?
* Accumulation of silt and high organic matter at the pond bottom
* Incidence of parasites and fish diseases
* Possibility of pathogens being transferred to humans
* Accumulation of heavy metals
## Footnote
These issues can negatively impact both fish health and human health.
126
What solutions are suggested for problems related to sewage fed culture systems?
* Regulation of treated sewage intake into ponds
* Dilution with freshwater and use of prophylactics
* Depuration of fish in freshwater before marketing
## Footnote
These measures aim to mitigate health risks and environmental impacts.
127
What are the three steps involved in the treatment of raw sewage?
* Mechanical treatment
* Chemical treatment
* Biological treatment
## Footnote
These steps help prepare sewage for safe use in fish culture.
128
What is the primary method of mechanical treatment for sewage?
Removal of suspended and floating solids using screens, skimming, and sedimentation.
## Footnote
Mechanical treatment is the first step in the sewage treatment process.
129
What does chemical treatment of raw sewage involve?
* Coagulation/chemical precipitation
* Deodorization
* Disinfection
* Sterilization
## Footnote
Chemical treatment aims to eliminate harmful substances from the sewage.
130
How is sewage treated biologically?
Using natural bacterial activity for the oxidation of organic matter.
## Footnote
This step is crucial for breaking down waste in sewage.
131
What is the ratio of sewage to water used in West Bengal's Bheries?
1:4, sewage to water.
## Footnote
This mixture allows for the settling of solids and the growth of plankton.
132
When does harvesting begin and end for fish in West Bengal's sewage fed culture?
Begins in September and ends in February.
## Footnote
This timeframe allows for optimal growth and yield of the fish.
133
What is the final yield from the sewage fed fish culture system in West Bengal?
About 3000 kg/ha/year.
## Footnote
This yield reflects the productivity of the Bheries using raw sewage.
134
True or False: Only treated sewage should be used for fish culture due to potential health hazards.
True.
## Footnote
Raw sewage poses significant health risks, necessitating treatment before use.
135
In which regions is treated sewage used for fish culture, aside from India?
* Far East
* Middle East
* Germany
* Hungary
* Israel
## Footnote
These regions have established practices for using treated sewage in aquaculture.
