Fish aquaculture (2) Flashcards
Ghalyoun farm
has 4.000 Fedon and it should increased to 9.500 Fedon (Fresh water because Egypt don’t have marine aquaculture)
Species
Nile tilapia
Blue tilapia
Mugil Capito (طوبار)
Mugil cephalus (بوري)
Common carp (مبروك)
Grass carp (مبروك)
Silver carp
Sea Bass (قاروص)
Sea bream (الدنيس)
Penaeus Japonicus (جمبري)
Nile tilapia VS Blue tilapia
Nile tilapia
The bands in caudal fin terminate with the end of fin
Blue tilapia
The bands in caudal fin terminate before the end of fin
Mugil cephalus
Has broadhead and has adipose flip on eye pupil
Common carp
Scattered scale
Carp family
Has lower palatability compared to tibia and they are fatty fish
Chinese origin
Grass carp
Diffuse scale
Silver carp
Has no teeth and fed on algae by suction
dorsal fin not divided
Spines are not classified in young and deposited inside flesh
Has lateral line
Sea Bass
carnivorous fish so it has teeth with terminal mouth
anterior and posterior dorsal fin
it’s marine water and adapted to burkes water and fresh water but with less growth rate
Penaeus Japonicus
White leg shrimp or litopeanus vonnmei which is not native but it has a huge advantage which is it can adopt on different levels off salinity and it can live in freshwater without any effects on its growth which will help us to produce it in deserts , It has two types salt shrimp and sweet shrimp
Aquaculture Systems (Diverse and complicated)
- Intensity & Density
- Culture
- Structures
- Farm integration
- Species stock for farming
- Water exchange
Intensity & Density
Extensive - intensive – semi intensive
Culture structures
Ponds - Tanks - raceways - cages - pens racks - long lines and floats
Farm integration
Integration of aquaculture
Species stock for farming
Monoculture - Polyculture
Water exchange
Open - static - semi closed - recirculation
Intensity & Density
Species and group difference → (depend on Marketable size)
Tilapia in RAS (recirculation) and shrimp in ponds
Tilapia has large size , if I want to produce shrimp (50 shrimp/m) I will not need filters but if I want to produce Tilapia at the same size I will need filters and it must be recirculating system
Natural ecosystem in sea
Top Predators → Small Fishes → Zooplankton → Phytoplankton
Zooplankton
Animal origin
Fed on Phytoplankton
Phytoplankton
Plant origin
Consuming CO2 and producing O2 by Photosynthesis
85% of O2 source
Extensive (متوسع)
Low Fish density
High natural food
Low Formulated food
Semi Intensive (شبه مكثف)
Moderate Fish density
Moderate natural food
Moderate Formulated food (supplement)
Intensive (مكثف)
High Fish density
Low natural food
High Formulated food
Extensive feeding
Natural food
Semi Intensive feeding
Natural food + Supplements
Intensive feeding
Artificial food
Why Intensive is risky system (Intensive disadvantages)?
- High inputs
- Large water requirement and I should exchange it regularly (Filters are not enough)
- High mortality rate and decline growth if I don’t clean water (↑ ammonia)
Why I must use artificial feed in intensive system ?
- Natural feed source is phytoplankton which is need fertilizers to grow up and do its Photosynthesis role , so if I exchange water regularly , the fertilizers will haven’t enough time to grow up and the phytoplankton will not grow up also
- The fertilizers decomposition will increase ammonia level because its organic matters
The organic matters (fertilizers) is …. by fish
not digested
Intensive aquaculture
- Extremely high stocking density (much higher than would ever be found in natural systems)
- Extra environmental control (i.e. temperature, dissolved oxygen, lighting, water quality requirement)
Intensive systems
Ponds
Cages
Raceways
Tanks
Ponds
Shrimp & tilapia with water exchange & padel aerator
Cages
Tilapia , Capito , Cephalus , silver carp & sea base and sea bream in Mediterranean
Raceways
Trout species , Narrow long structure has a source of correct water
Tanks
Eels in japan
A complete over environmental conditions within the system
- Mostly , intensive systems are indoors so that climate control does not have to be maintained for each individual system (e.g. or raceway)
- High degree of control required, aeration and water retreatment systems are sophisticated
- Skilled technicians to monitor and maintain them
- Automatic generator
Intensive systems are …..
indoors so that climate control does not have to be maintained for each individual system (e.g. or raceway)
A properly designed and maintained intensive aquaculture system
the highest yield per unit volume or space of any aquaculture system
However ; might be Risky and Expensive
