This document provides information on common freshwater fish species in India, definitions of phytoplankton and zooplankton, objectives of polyculture fish farming systems, advantages of rice-fish culture and suitable fish species. It also discusses stocking densities for polyculture and rice-fish systems.

1. 1.listdown15 freshwatercommoncultural fishname withtheirscientificname
Ans:Local name: Scientificname:
Rui Labeo rohita
Katol Catlacatla
Darkina Rasbora rasbora
Shoul Channastriata
Taki Channapunctatus
Kalibaus Labeo calbasu
Bata Labeo-bata
Mrigal Cirrhinuscirrhosus
Commoncarp Cyprinuscarpio
Mirror carp Cyprinussp.
Shorputi Puntiussarana
Tita-punti Puntiusticto
Pangas Pangasiuspangasius
Ilish Tenualosailisha
Gozar Channamarulius
2.Define phytoplanktonandzooplankton.Writefivephytoplanktonandfivezooplanktonscientific
name
Ans:Phytoplankton: Planktoncomes from the Greek word “planktos” whichmeansdrifter.
Phytoplankton
Aquatic microscopic or macroscopic drifting plants such as Diatoms, Dinoflagellates etc.
1. Diatoms 2.Volvox3. Anabaena4. Pinnularia5. Navicula

2. • Zooplankton: Microcopicanimalsarecalled zooplankton.
Some of the zooplanktonareherbivorus,meaningthey eat phytoplankton
1. Amphlipod2. Daphnia3. Copepod4. Rotifera5. Diaptomus
3.What are the main objectivesfor polyculturesystem?Illustratethe pondpolyculturesystem
 Ans:Objectives: Polycultureis the practice of culturingmore thanone species of fishinthe
same pond.
 The basic principal ofpolycultureis that the cultivation ofvariousfishspecies having
differentfood habitsto maximizethe total productionper unit area with the proper utilization
of availablefoodina pond.
 There shouldbe a compatiblecombinationofspecieswithdiversifiedfeedinghabitthat should
include surface/columnfeedersto bottom feeders as well as omnivoroustomacrovegetation
feedingfishspecies.
4.
5.Write the advantagesof rice –fish culture,stockingdensity, suitablefishspeciesname
Ans:Advantagesofrice –fish culture: Advantages
i. We get fishesas a extra crop with rice.
ii. Pondis not needed for fishculture.
iii. Fisheseat insects,weeds etc. fromthe rice field,thus reduce the rice productioncosts.
iv. Fishexcreta act as fertilizer.
v. Increased mineralizationoftheorganic matter andincreased aerationof the soil.
Rice yield is increasedup to 10% of total production
stockingdensity: 3000-4000 fishfingerlingsarestocked for 1ha rice field.
Time of stocking
Fishfingerlingsare stocked after 10-15 days of rice transplantingor 1 month ofsowingseeds in
direct cropping.
[N.B:make sure that rice plantshave been establishedinthe field]
suitablefishspecies name:

3. Fish species
Catla
Rui
Mrigal
Common carp
Silver carp
Grass carp
Fish species Species ratio Number o
fingerlings/
Nilotica 75 – 85% 2250 – 300
Common carp 10 – 15% 300 -- 400
Magur or shing 5 – 10% 150 - 200
density
3000-4000 fish fingerlings are stocked for 1ha rice field.
6.Write the advantagesof chicken cumfishes?How manychicken birdsare allocatedforone hector
ponds. what will be the housesize?

4.  Ans: advantagesofchicken cum fishes :We can get fish,eggs andmeat or fish andmeat from
the same place.
 Chicken manureproduces enoughnatural fishfeed organismswithoutthe use of any
additional manure/fertilizer.
 No supplementaryfeed isneeded for the fish.
 No extra space isrequired for chicken farming.Chickensheds canbe constructedover the
pondwater or on the dyke.
How many :It is foundthat 500- 600 chickens/ ha water spreadarea is sufficientto produce
manure to fertilizea pondof 1 hector water spreadarea underfish culture.
 House size: Floorspace, nests,ventilation,temperature regulatingdevice,dryness, lightand
sanitationare the mainfeatures to be considered duringshed construction.
 Size ofthe housedepends on the number ofbirds to be kept.
 Normally2–3 sq. ft. area is required fora layer chicken and 1–1.5 sq.ft for a broiler.
 A chicken houseover the pondwater, the hole sizeof the floor shouldbe around 1-1.5 cm2
.
7. Writethe advantagesofDuck cumfishes?How manyDucks are allocatedforone hector ponds.
what will be the housesize?
1. Ans: advantagesofDuck cumfishes: Fromthe same placesat the sametime duck meat &
eggs andalso the fishcan be produced.
2. Duck get 50- 75% of their total feed requirement fromthe ponditself.So only50-25% feed is
suppliedto the ducks.
3. Fishutilizesthe feed spilledby ducks andeat their droppingsdirectlyby somefishes.
4. Ducks keep water plants/ weeds incheck.
5. Dick droppingact as a goodfertilizer whichhelpsin producingfishfeed i.e. phytoplankton&
zooplanktoninfishpond.
6. This cuts the cost of fishproductionby60%
7. Ducks increases the pondproductivityby releasingthe nutrients from the pondbottom soil
throughdabblingthe pondbottommud.
 How many: It is foundthat 200- 300 ducks/ hawater spread area issufficientto produce
manure to fertilizea pondof 1 hector water spreadarea underfish culture.

5.  House size: 3- 4 monthsaged ducklingsare introducedintothe duck houseafter 1 monthof
stockingthe pond withfishseed.
 The duckhouse andthe materialsthat are goingto use shouldbe disinfected
 Ducklingsare not allowedthe free range in the pondwater till the cultured fishattaina
fingerlingsizeor 10- 15 cm in length.
8.Describe Turbidityanddraw the Secchi disk
Ans:
Turbidity
 Turbidity result fromdue to suspendedinorganic substances suchas silt
and clay, or due toplanktonic organisms.
 Ponds with clay bottoms are likely to have high turbidity.
 Ponds with sand, gravel and humus predominate are likely to have low
turbidity.
 Turbidity restricts the penetration of sunlight and thus reduces
photosynthesis rate as a result reduce phytoplankton in the pond.
9.Fill in the Blanks:
1. Foodchaindescribe a singlepath way of…………….transfer
2.Rice fishculture enhance………%riceproduction Ans: 10%

6. 3.Optimumtemperature for fishgrowthis……..Ans: 20-33°C
4.Gill cloggingdiseaseforfishdue to turbidityupto……..Ans: 175g/L to 225 g/L
 5. Optimumlevel for Dissolvedoxygen is……..forfishcultureAns: 3-5 mg/Lor ppm.
6.Draw Scenedesmus…….
7.Predatory fishconsumed……..gof fishfor ……..ggrowth Ans: 5 to 7g 1g.
8.Pond fertilizationratefor polyculture,Urea………kg/ha,cowdung…….kh/ha Ans: 10 400
9.Stockingdensity for polyculturesystem………fingerlings/ha Ans: 700–900
10.polyculture beganin chinamore than……..yearsago Ans: 1000
11. Ecology is the scientific study of ……Ans: the relationship among living organisms and their
natural environment.
Q.1.What do you mean by phytophagous?
Ans: (especially of an insect or other invertebrate) feeding on plants.

7. Feeding on plants, including shrubs and trees. Used especially of certain
insects.
2.Define phytoplankton and zooplankton.
Phytoplankton
Aquatic microscopic or macroscopic drifting plants such as Diatoms, Dinoflagellates etc.
• zooplankton.
• Microcopic animals are called zooplankton.
• Some of the zooplankton are herbivorus, meaning they eat phytoplankton.
3.Why rice fish farming is an intrigated process
 Ans: Usuallyfertilizersare not neededforrice because fishexcretaact as organic fertilizer.
 Fishes eat weeds as feed therefore weeding is not also needed.
 In rice cum fish culture is an integrated pest management is practiced to control
insects.
 If the insects infestation is much more then pesticide is used.
 Before applying pesticide, all fishes are taken into the big drain.
 After applying pesticide, irrigation to be supplied.
 8-10 days of irrigation fishes are releasedfrom the drain.
4.Write two poultry names for poultry cum fish culture practice
Ans:
Leghorn Layer hybrid
Rhode Island Red Layer hybrid
Bard Ploumouth Rock
(BPR)
Broiler hybrid
5. whatis pisciculture?

8. Ans: Pisciculture: The breeding, rearing, and transplantation of fish by artificial means is called
pisciculture.
6.What doyou mean by aquaculture?
Ans: Aquaculture/Aquafarming: It is the farming of aquatic organisms such as fish, mollusc
and aquatic plants. It involves cultivating freshwater and saltwater populations under controlled
conditions.
7.Write CO2 effects as water qualitywith chemical reactions
 Ans: Carbondioxide(CO2):
 CO2 is derived in natural waters from varioussources,viz;
a). Fromatmosphere
b). Respirationofanimalsandplants
c). Bacterial decompositionoforganicmatter
 Rain water contains0.6 mg/LdissolvedCO2.
 The reactionbetween CO2 and H2O results inthe formationofH2CO3 (carbonicacid) which
displaysitsweak acid character through dissociationintoH+
and HCO3-
(bicarbonate).
Chemical Characteristics
 As rain water react withsoil containingCO2 due to decomposition.
Suitablerange for dissolvedCO2 is0.5 to 1.0 mg/Lfor maximumfishproduction
8.Write alkalinityeffectsas water qualitywith chemical reactions
 Ans: Alkalinity
 Alkalinityisa measure of the acid-combiningcapacityofthewater , it is alsocalled the
bufferingability.
 Alkalinitymeasurethe amountsof the carbonates andbicarbonatesin the water.
 Alkalinityof50 - 200ppm are the more productivefor fish.
 Like pH andhardness,it can be corrected and controlledby addinglimeto the pond.
Low alkalinity=lowpH=Low Hardness

9. Or, High alkalinity=highpH=highhardness
9.Write pH effects aswater quality
Ans: pH is the negative logarithmofhydrogen ion concentrationi.e., –Log.[H+]
ii). pH value= 7 is the neutral point.
iii).When pH <7 then it isacidic innature.
iv).When pH > 7 then it isalkalinein nature.
iv).pH scaleis pH = 0~14.
Water with a pH between 6.5 and 8 are best for aquaculture