1. Tilapia can be cultured using mixed-sex or mono-sex culture systems, with mono-sex culture having advantages of larger harvest weight and uniform size due to excluding female reproduction.
2. Tilapia are commonly spawned in ponds, cages, or tanks and can be produced using several techniques including visual selection, hybridization, sex-reversal, and genetic manipulation to achieve all-male populations for grow out.
3. Tilapia have a wide temperature tolerance and are omnivorous filter feeders, reaching sexual maturity at 5-6 months when water temperatures reach 24°C, making them suitable for aquaculture in tropical and subtropical regions.
Reproduction is a fundamental biological process which enables continuation of species. In fisheries biology, reproduction assumes greater significance to understand sexual
dimorphism, process of maturation, size or age of maturity, breeding season, spawning area, sexual segregation, migration, fecundity, embryonic and larval development and
recruitment. Most of the management strategies in capture fisheries are based on reference points that are the manifestations of reproductive biology. In aquaculture,
knowledge of reproductive biology of a fish is essential for hatchery production of fish feeds.
,
Nazmul Haque Syekat
Reproduction is a fundamental biological process which enables continuation of species. In fisheries biology, reproduction assumes greater significance to understand sexual
dimorphism, process of maturation, size or age of maturity, breeding season, spawning area, sexual segregation, migration, fecundity, embryonic and larval development and
recruitment. Most of the management strategies in capture fisheries are based on reference points that are the manifestations of reproductive biology. In aquaculture,
knowledge of reproductive biology of a fish is essential for hatchery production of fish feeds.
,
Nazmul Haque Syekat
A SEMINAR ON INDUCING AGENTS OF HYPOPHYSATIONKartik Mondal
The precise combination of environmental factors required for maturation, ovulation and spawning.
However, quite often, under farm conditions, the requisite environmental factors are either not available or do not persist for sufficient length of time for spontaneous maturation to occur.
The pioneering discovery of B.A. Houssay (1931) and Von Ihering (1935, 1937, Argentina) that fishes can be induced to spawn by injecting pituitary homogenates has somewhat mitigated the problem.
The principal advantage of this technique, referred to in aquaculture parlance as “Hypophysation.”
What is the stocking density of fish in semi intensive cultureihn FreeStyle Corp.
Stocking Density: Stocking density also known as per-unit stocking amount or stocking rate, refers to the quantity of fry or fingerlings per unit of water area.
Poly Culture: The concept of poly culture of fish is based on the concept of total utilization of different trophic and spatial niches of a pond in order to obtain maximum fish production per unit area. Different compatible species of fish of different trophic and spatial niches are raised together in the same pond to utilize all sorts of natural food available in the pond.
Semi Intensive Culture: Semi-intensive culture systems depend largely on natural food which is increased over baseline levels by fertilization and/or use of supplementary feed to complement natural food.
fish nutrition and feeding of fish. different methods of feeding fish. fish feeding behavior. daily feed requirements for fish. storage and selection of quality feeds keeping records of fish feeding and feeder types for fish. FCR and Uniform growth of fish are the ultimate goals to be achieved. university of veterinary and animal sciences Lahore.
fish farming integrated agriculture RATIONAL OF IFS
GOALS OF IFS
ADVANTAGES OF INTEGRATED FISH FARMING (IFF)
FISH CULTURE PRACTICES
POULTRY FARMING PRACTICES
PRODUCTION DETAILS
CONCLUSION
KVK ACTIVITIES Increased productivity, profitability and sustainability are ensured with protective food and environmental safety.
Employment generation and ultimately increasing the standard of living of the farmers are other major benefits of integrated farming system.
Obtaining food and nutritional security at farm level and can also generate rural employment, thus preventing excessive migration to urban areas.
Shrimp farming in India, till 2009, was synonymous with the mono culture of tiger shrimp, Penaeus monodon. About 1,90,000 ha brackishwater area have been developed for shrimp culture in the country spread over all the coastal states. Since 1995 culture of P monodon is affected by White Spot Syndrome Virus (WSSV) and the development of shrimp farming has become stagnant.
Most of the Southeast Asian countries like Thailand, Vietnam, Indonesia were also culturing P. monodon and since 2001-02 onwards most of them have shifted to culture of exotic Whiteleg shrimp,Litopenaeus vannamei because of the availability of Specific Pathogen Free (SPF) and Specific Pathogen Resistant (SPR) broodstock. In India, Pilot-scale introduction of L.vannamei was initiated in 2003 and after a risk analysis study large-scale introduction has been permitted in 2009.
Introduction
Fish Health Management GOALS
Principles of fish health management
Factors affecting fish health
Common symptoms of diseases
General preventive measures
Proper Health Management through Manipulating the disease triangle
Conclusion
References
Nutritional requirement of larvae and broodstock of commercially important fi...Akhila S
the presentation provides the details regarding, Tthe broodstock nutrition, essential nutrients and recent data on broodstock nutrition; also larval nutrition; the hatchery utilised live feeds in detail and also microparticulate diet, the recent knowlwdge on essential elements amd minerals in larval nutrition, like taurine, phospholipids, liposomes, waxy spray beds etc
A SEMINAR ON INDUCING AGENTS OF HYPOPHYSATIONKartik Mondal
The precise combination of environmental factors required for maturation, ovulation and spawning.
However, quite often, under farm conditions, the requisite environmental factors are either not available or do not persist for sufficient length of time for spontaneous maturation to occur.
The pioneering discovery of B.A. Houssay (1931) and Von Ihering (1935, 1937, Argentina) that fishes can be induced to spawn by injecting pituitary homogenates has somewhat mitigated the problem.
The principal advantage of this technique, referred to in aquaculture parlance as “Hypophysation.”
What is the stocking density of fish in semi intensive cultureihn FreeStyle Corp.
Stocking Density: Stocking density also known as per-unit stocking amount or stocking rate, refers to the quantity of fry or fingerlings per unit of water area.
Poly Culture: The concept of poly culture of fish is based on the concept of total utilization of different trophic and spatial niches of a pond in order to obtain maximum fish production per unit area. Different compatible species of fish of different trophic and spatial niches are raised together in the same pond to utilize all sorts of natural food available in the pond.
Semi Intensive Culture: Semi-intensive culture systems depend largely on natural food which is increased over baseline levels by fertilization and/or use of supplementary feed to complement natural food.
fish nutrition and feeding of fish. different methods of feeding fish. fish feeding behavior. daily feed requirements for fish. storage and selection of quality feeds keeping records of fish feeding and feeder types for fish. FCR and Uniform growth of fish are the ultimate goals to be achieved. university of veterinary and animal sciences Lahore.
fish farming integrated agriculture RATIONAL OF IFS
GOALS OF IFS
ADVANTAGES OF INTEGRATED FISH FARMING (IFF)
FISH CULTURE PRACTICES
POULTRY FARMING PRACTICES
PRODUCTION DETAILS
CONCLUSION
KVK ACTIVITIES Increased productivity, profitability and sustainability are ensured with protective food and environmental safety.
Employment generation and ultimately increasing the standard of living of the farmers are other major benefits of integrated farming system.
Obtaining food and nutritional security at farm level and can also generate rural employment, thus preventing excessive migration to urban areas.
Shrimp farming in India, till 2009, was synonymous with the mono culture of tiger shrimp, Penaeus monodon. About 1,90,000 ha brackishwater area have been developed for shrimp culture in the country spread over all the coastal states. Since 1995 culture of P monodon is affected by White Spot Syndrome Virus (WSSV) and the development of shrimp farming has become stagnant.
Most of the Southeast Asian countries like Thailand, Vietnam, Indonesia were also culturing P. monodon and since 2001-02 onwards most of them have shifted to culture of exotic Whiteleg shrimp,Litopenaeus vannamei because of the availability of Specific Pathogen Free (SPF) and Specific Pathogen Resistant (SPR) broodstock. In India, Pilot-scale introduction of L.vannamei was initiated in 2003 and after a risk analysis study large-scale introduction has been permitted in 2009.
Introduction
Fish Health Management GOALS
Principles of fish health management
Factors affecting fish health
Common symptoms of diseases
General preventive measures
Proper Health Management through Manipulating the disease triangle
Conclusion
References
Nutritional requirement of larvae and broodstock of commercially important fi...Akhila S
the presentation provides the details regarding, Tthe broodstock nutrition, essential nutrients and recent data on broodstock nutrition; also larval nutrition; the hatchery utilised live feeds in detail and also microparticulate diet, the recent knowlwdge on essential elements amd minerals in larval nutrition, like taurine, phospholipids, liposomes, waxy spray beds etc
Culture Of Cobia- Its Biology, Seed Collection & Culture TechniquesHaladharHembram2
Cobia , Rachycentron canadum also known as Lemon fish or Ling is an oceanodromous , migratory and pelagic fish that lives in brackish and marine waters.
The fish is popular known by the common names-Black kingfish, Black salmon, runner or sergeant fish, crab eater and Sea murrel.
It is a highly priced game fish with high market value both in domestic and international markets.
Cobia known for its excellent meat quality is a famous premium food fish highly preferred by people in Taiwan and Japan. The white meat of the fish is served in restaurants as raw fish called Sashimi.
The fast growth rate, adaptability to captive breeding (attains 6-8 kg/year) are the major attributes which makes cobia as an excellent candidate species for aquaculture.
Cobia is one of the marine finfish species with high aquaculture potential particularly for cage culture in India.
The principle of integrated fish farming involves farming of fish along with livestock or/and agricultural crops.. This type of farming offers great efficiency in resource utilization, as waste or by product from one system is
effectively recycled. It also enables effective utilization of available farming space for maximizing production.
•The rising cost of protein-rich fish food and chemical fertilizers
as well as the general concern for energy conservation have created awareness in the utilization of rice and other crop fields and livestock wastes for fish culture. Fish culture in combination with agriculture or livestock is a unique and lucrative venture and provides a higher farm income, makes available a cheap source of protein for the
rural population, increases productivity on small land-holdings
and increases the supply of feeds for the farm livestock.
Scope of Integrated Fish Farming
The scope of integrated farming is considerably
wide. Ducks and geese are raised in pond, and pond- dykes are used for horticultural and agricultural
crop products and animal rearing.
The system provides meat, milk, eggs, fruits,
vegetables, mushroom, fodder and grains, in
addition to fish.
Hence this system provides better production, provides more employment, and improves socio- economic status of farmers and betterment of rural economy.
Classification of Integrated Fish Farming
Integrated fish farming can be broadly classified into two, namely Agriculture-fish and Livestock-fish systems
Agriculture-fish systems- Agri-based systems include rice-fish integration,
horticulture-fish system, mushroom- fish system, seri-fish system.
Livestock-fish systems- Livestock-fish system includes cattle-fish system, system, pig-fish system, poultry-fish system, duck-fish system, goat-fish system, rabbit-fish system.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
2. Grow-out:
Mixed-sex
Culture
Disadvantages:
1. Small harvest weight
2. Mixed sizes at harvest
Advantages:
Technically
easy
Mono-sex
culture
Advantages:
1. Large harvest weight
2. Uniform size at
harvest
Disadvantage:
Technically
difficult
3. Tropical species Prefers to live in
shallow water.
Lethal temperatures
Lower
11-12 °C,
Upper 42 °C
Preferred temperature
31 to 36 °C.
4. Omnivorous grazer
Phytoplankton, Periphyton
,aquatic plants small
invertebrates, benthic fauna
detritus and bacterial films
associated with detritus.
Feeding
Filter feeding
Feed by entrapping suspended
particles, including
phytoplankton and bacteria,
on mucous in the buccal
cavity,
Main source of nutrition : surface grazing on periphyton mats.
5. •Sexual maturity in ponds is reached at an age of 5-6 months.
Spawning begins when the water temperature reaches 24 °C.
• The breeding process starts when the male establishes a territory,
digs a craterlike spawning nest and guards his territory called as lek.
•Nests are prepared by scooping out depressions at pond bottom.
Mature female visits the pond and there is immediate courtship and
mating.
6. •The ripe female spawns in the nest, and immediately after
fertilization by the male, collects the eggs into her mouth and moves
off.
•The female incubates the eggs in her mouth and broods the fry after
hatching until the yolk sac is absorbed. Incubating and brooding is
accomplished in 1 to 2 weeks, depending on temperature.
•After fry are released, they may swim back into her mouth if danger
threatens. Being a maternal mouth brooder, the number of eggs per
spawn is small in comparison with most other pond fishes.
7. •Egg number is proportional to the body weight of the female. A 100
g female will produce about 100 eggs per spawn, while a female
weighing 600-1 000 g can produce 1 000 to 1 500 eggs.
• The male remains in his territory, guarding the nest, and is able to
fertilize eggs from a succession of females.
•If there is no cold period, during which spawning is suppressed, the
female may spawn continuously.
•While the female is brooding, she eats little or nothing. Nile tilapia
can live longer than 10 years and reach a weight exceeding 5 kg.
8. Eggs can be removed from females Yolk-sac tilapia fry
Females incubate eggs
defend the fry
10. SEED SUPPLY
Tilapia are asynchronous breeders. Hormones are not used to
induce spawning, which occurs throughout the year in the tropics
and during the warm season in the subtropics.
Breeding is conducted in ponds, tanks or hapas. The stocking ratio
for females to males is 1-4:1 with 2 or 3:1 being the most common
The brood fish stocking rate is variable, ranging from 0.3-0.7
kg/m2 in small tanks to 0.2 - 0.3 kg/m2 in ponds.
The popular hapa-in-pond spawning system in Southeast Asia uses
100 g brood fish stocked at 0.7 kg/m2.
11. Spawning ponds are generally 2000 m2 or smaller. In Southeast
Asia, a common hapa size is 120 m2.
Brood fish are given high quality feed at 0.5-2 percent of body
weight daily. Swim-up fry gather at the edge of a tank or pond and
can be collected with fine-mesh nets
.
Fry collection can begin 10 to 15 days after stocking. Multiple
harvests (six times per day at 5 day intervals) are conducted up to a
maximum of 8-10 weeks before pond drainage and a complete
harvest is necessary.
Tanks must be drained and recycled every 1-2 months because
escaped fry are very predaceous on fry from subsequent spawns..
12. Alternatively tanks or ponds are harvested completely after a 2-
4 week spawning period. Production of optimum-sized (<14
mm) fry ranges from 1.5 to 2.5 fry/m2/day (20 to 60 fry/kg
female/day).
In the South East Asian hapa method, fish are examined
individually every 5 days to collect eggs. This system is much
more productive, but it is labour intensive. Brood fish are more
productive if they are separated by sex and rested after
spawning.
13. Mono-sex male tilapia populations can be produced by:
Visual selection
Hybridization
Sex-reversal
Genetic manipulation
14. Visual selection
Male Female
Two apertures on ventral side
of belly
Anus and urinogenital.
Three apertures- anus, urinary
And genital aperture.
Urinogenital aperture smaller. Bigger Urinogenital aperture.
16. •Commercial tilapia production generally requires the use of male
monosex populations.
•Male tilapia grow approximately twice as fast as females.
•Therefore, mixed-sex populations develop a large size disparity
among harvested fish, which affects marketability.
•Moreover, the presence of female tilapia leads to uncontrolled
reproduction, excessive recruitment of fingerlings, competition for
food, and stunting of the original stock, which may not reach
marketable size.
Sex-reversal
17. • In mixed-sexed populations, the weight of recruits may
constitute up to 70 percent of the total harvest weight. It is
therefore necessary to reverse the sex of female fry.
• This is possible because tilapia do become sexually
differentiated for several days after yolk sac absorption. If
female tilapia receive a male sex hormone (17 α
methyltestosterone, MT) in their feed, they will develop as
phenotypic males.
• Fry collected from breeding facilities need to be graded
through 3.2 mm mesh material to remove fish that are >14 mm,
which are too old for successful sex reversal.
18. •Swim-up fry are generally <9 mm. MT is added to a powdered
commercial feed or powdered fish meal, containing >40 percent
protein, by dissolving it in 95-100 percent ethanol, which is mixed
with the feed to create a concentration of 60 mg MT/kg feed after
the alcohol has evaporated.
•The alcohol carrier is usually added at 200 ml/kg feed and mixed
thoroughly until all the feed is moist.
•The moist feed is air dried out of direct sunlight, or stirred in a
mixer until dried, and then stored under dark, dry conditions.
Androgens break down when exposed to sunlight or high
temperatures.
•Fry are stocked at 3 000 to 4 000/m2 in hapas or tanks with water
exchange.
19. •Stocking densities as high as 20 000/m2 have been used if good
water quality can be maintained.
• An initial feeding rate of 20-30 percent body weight per day is
gradually decreased to 10-20 percent by the end of a 3 to 4 week
sex-reversal period.
• Rations are adjusted daily, and feed is administered four or more
times per day.
•If sex-reversal is conducted in hapas, the feed must be of a
consistency that allows it to float,otherwise a considerable amount
of feed would be lost as it settles through the bottom of the hapa.
20. •Sex-reversed fry reach an average of 0.2 g after 3 weeks and 0.4 g
after 4 weeks. The average efficacy of sex-reversal ranges from 95 to
100 percent depending on the intensity of management.
•Feminization of genetic male done through estrogen – these
functional females when mated with genotypic males all male
offsprings are produced.
21. XX “F” + XY “M”
1- XY “F” x XY “F”
2 - XY “ F” x XY “ M”
3-XX “ F ” + 2 XY “ M” + YY “ M”
XX “F” x YY “M”
100 % XY “ M”
Genetic Manipulation
estrogen
22. •After sex-reversal, fingerlings are generally nursed to an advanced
size before they are stocked into grow-out facilities.
•This procedure increases survival in the grow-out stage and utilizes
growing space more efficiently.
• Sex-reversed fingerlings are stocked at approximately 20-25
fish/m2 in small ponds and cultured for 2-3 months to an average size
of 30-40 g.
•The ponds should be filled immediately before stocking to prevent
the build-up of predaceous aquatic insects. Final biomass at harvest
should not exceed 6000 kg/ha.
Nursery
23. •A series of small cages (<4 m3) with increasing mesh size can be
used to rear advanced fingerlings.
• Sex-reversed fingerlings can be stocked at a rate of 3 000
fish/m3 and grown for 6 weeks until they average 10 g.
•Fish of this size can be restocked at 2 500 fish/m3 to produce 25-30
g fingerlings in 4 weeks.
• These fish can be stocked at 1 500 fish/m3 to produce 50-60 g
fingerlings in 4 weeks. A recirculation system stocked at 1 000
fish/m3 will produce 50 g fingerlings in 12 weeks. Fingerlings should
be fed 3-4 times daily.
•In ponds, fingerlings are given extruded feed (30 percent protein) at
an initial rate of 8-15 percent of biomass per day, which is gradually
decreased to a final rate of 4-9 percent per day.
24. Tilapia can be spawned in:
1. Ponds 2. Cages ( hapas )
3. Tanks
25. POND CULTURE
Pond culture of tilapia is conducted with a variety of inputs
such as agricultural by-products (brans, oil cakes, vegetation
and manures).
Chicken manure weekly at 200-250 kg DM (dry matter)/ha and
supplementing it with urea and triple super phosphate (TSP) at
28 kg N/ha/week and 7 kg P/ha/week , inorganic fertilizers and
feed.
To reduce production costs for domestic markets in developing
countries, two strategies are followed: delayed feeding and
supplementary feeding.
Tilapia are stocked at 3 fish/m2 and grown to 100-150 g in
about 3 months with fertilizer alone, and then given
supplemental feeding at 50 percent satiation until the fish reach
500 g
26. Floating cages
Mesh size has a significant impact on production and should
be 1.9 cm or greater to maintain free circulation of water.
Advantages.
The breeding cycle of tilapia is disrupted in cages, and
therefore mixed-sex populations can be reared in cages without
the problems of recruitment and stunting. Eggs fall through the
cage bottom or do not develop if they are fertilized
Use of waterbodies that cannot be drained or seined and would
otherwise not be suitable for aquaculture.
Flexibility of management with multiple production units.
Ease and low cost of harvesting.
Close observation of fish feeding response and health.
Relatively low capital investment compared to other culture
techniques.
27. Tanks and raceways
Tilapia are cultured in tanks and raceways of varying sizes (10-1 000
m3) and shapes (circular, rectangular, square and oval).
The maximum tilapia density in raceways ranges from 160-185
kg/m3, and maximum loading ranges from 1.2-1.5 kg/litre/min
.
A common production level in raceways is 10 kg/m3/month, as
water supplies are often insufficient to attain maximum rates.
Production levels are considerably lower in tanks with limited water
exchange, but water use efficiency is much higher in these systems.
28. Harvesting techniques
Complete harvests are necessary in ponds and are
accomplished by seining in combination with draining.
A complete harvest is not possible by seining alone as tilapia
are adept at escaping seine nets.
The pond should be dried between production cycles or treated
with pesticides to kill tilapia fry to avoid carryover to the next
production cycle.
Partial harvests of tanks, raceways and recirculation systems,
which maximize production, are accomplished with grader bars
to remove the largest fish.
29. •Prepared feeds that provide a complete diet (adequate protein,
lipids, carbohydrates, vitamins and minerals) are readily available
in developed countries and are also manufactured and available in
developing countries with an export market for high quality tilapia
products.
•Some of the main feed ingredients such as soybean meal or
fishmeal may be imported.
• Prepared feeds are often too expensive for the production of
tilapia sold in domestic markets in developing countries; however,
manures and agricultural by-products are used to produce tilapia
cost effectively.
•In developing countries without a tilapia export market, farmers
rely exclusively on manures and agricultural by-products, as
prepared feeds are not available.
Feed
30. GIFT Tilapia
• A pioneering selective breeding program that began in 1988 to led
to the development of the Genetically Improved Farmed Tilapia
(GIFT) strain by World Fish and partners.
•Selective breeding is the process of choosing the parents of the next
generation in such a way that it will result in improved performance
for certain traits considered to be important during production and
marketing.
31. Why Tilapia?
•It can be grown in diverse farming systems and is
omnivorous, requiring minimal fish meal in its feed.
• It has a naturally high tolerance to variable water quality and
can grow in both freshwater and marine environments
.
•Because tilapia are hardy and have good disease resistance,
they are inexpensive and easy for small-scale farmers to grow
for food, nutrition and income.
•Tilapia is an affordable source of protein, vitamins, minerals
and essential fatty acids that are vital for good health. GIFT
and other improved strains of Nile tilapia have helped improve
food and nutrition security in the developing world.