Clarias batrachus, commonly known as the walking catfish or Thai catfish, is a species of air-breathing catfish. Here's some information about the reproduction, breeding techniques, hormonal usage, and related aspects of Clarias batrachus:
1. Sexual Dimorphism: Male and female walking catfish can be distinguished based on certain physical characteristics. Males tend to have a larger size, broader head, and more prominent spines on their pectoral fins compared to females.
2. Breeding Conditions: Walking catfish are known to breed during the rainy season or when there is an increase in water levels. They typically prefer warm water temperatures.
3. Spawning Behavior: Walking catfish are nest builders, and males exhibit paternal care. The male constructs a nest by digging a depression in the substrate, often in muddy areas or among aquatic vegetation.
4. Hormonal Induction: In aquaculture settings, hormonal induction is commonly used to synchronize and stimulate breeding in walking catfish. Hormones like human chorionic gonadotropin (hCG), luteinizing hormone-releasing hormone analogs (LHRHa), or synthetic hormone analogs are used to induce ovulation in females and spermiation in males. The dosage and timing of hormone administration depend on factors such as fish size, maturity, water temperature, and breeding objectives.
5. Breeding Tank Setup: Prepare suitable breeding tanks or ponds for walking catfish reproduction. The tanks should have appropriate water conditions, including a temperature range of 25-30°C (77-86°F), pH around 7, and good aeration to ensure oxygen supply.
6. Hormone Injection: Hormonal injection is typically performed on female walking catfish to induce ovulation. The hormone is administered through intramuscular or subcutaneous injections. It is important to handle the fish carefully during the injection process to minimize stress and ensure proper dosage delivery.
7. Spawning Technique: After hormone injection, the female walking catfish is introduced into the male's nest. The male initiates courtship behavior by circling, nudging, and wrapping his body around the female. This stimulates the release of eggs by the female and sperm by the male for fertilization.
8. Nest Construction and Preparation: Male walking catfish construct nests by excavating depressions in the substrate. They may create tunnels leading to the nest for protection. Nests are usually built in shallow waters, often in muddy areas or among aquatic vegetation.
9. Egg Collection and Incubation: Once the eggs are fertilized, they adhere to the nest walls. The male walking catfish guards the nest and ensures adequate oxygenation of the eggs by fanning them with his pectoral fins. During incubation, maintain suitable water conditions and temperature for the eggs to develop.
Larval Rearing: After hatching, the walking catfish larvae have external gills and can breathe atmospheric air. Provide appropriate rearing conditions, including water quality, temperature.
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.”
Setting an aquarium is an important steps to maintaining healthy ornamental fishes. It gives mind relaxation and peaceful. It is a hobby and reduces the stress also
lobsters and crab fisheries in INDIA is a vast and enormous amount of catch and exports are being made.
this slide describes about the methods, distribution, annual landings and important species of lobster and crabs in India.
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.”
Setting an aquarium is an important steps to maintaining healthy ornamental fishes. It gives mind relaxation and peaceful. It is a hobby and reduces the stress also
lobsters and crab fisheries in INDIA is a vast and enormous amount of catch and exports are being made.
this slide describes about the methods, distribution, annual landings and important species of lobster and crabs in India.
it is about the length and weight relationship of fish , growth, length, weight, absolute growth, isometric growth, relative growth, allometric growth,
Seed production of giant freshwater prawn fisheries pptAshish sahu
Giant freshwater prawn seed production starts in Andaman - INDIA - A scientist and his team of the Division of Fisheries Science, Central Agricultural Research Institute (CARI), Port Blair, have initiated research on breeding and larval rearing of Giant Freshwater Prawn (M Rosenbergii) under controlled conditions at the CARI farm complex.
A short description about magur fish.The walking catfish (Clarias batrachus) is a species of freshwater airbreathing catfish native to Southeast Asia, but also introduced outside its native range where it is considered an invasive species. It is named for its ability to "walk" across dry land, to find food or suitable environments. While it does not truly walk as most bipeds or quadrupeds do, it has the ability to use its pectoral fins to keep it upright as it makes a wiggling motion with snakelike movements.[2] This fish normally lives in slow-moving and often stagnant waters in ponds, swamps, streams and rivers, flooded rice paddies or temporary pools which may dry up
Nutritional requirement of cultivable fin fish: larvae, juveniles and adultsDebiprasad1997
Fish is among the healthiest foods on the planet. It is loaded with important nutrients, such as protein and vitamin D. Fish is also the world's best source of omega-3 fatty acids, which are incredibly important for human body and brain.
Manufactured feeds are an important part of modern commercial aquaculture, providing the balanced nutrition needed by farmed fish.
In the development of modern aquaculture, starting in the 1970s, fishmeal and fish oil were key components of the feeds for these species. They are combined with other ingredients such as vegetable proteins, cereal grains, vitamins and minerals and formed into feed pellets.
The global supply of fish meal and fish oil is finite and fully utilized. Alternative or nontraditional feedstuffs may differ in terms of taste, smell, texture, and color, as well as nutrient composition, from the traditional feedstuffs, which are produced largely from the natural prey of the fish being raised. Alternative feedstuffs may also contain compounds and antinutritional factors that affect digestive or sensory physiology.
Another important area of fish nutrition for the next 20 years will be larval fish nutrition. Currently, the cost and difficulty of rearing a great number of species from the first feeding to the juvenile stage are the most severe bottlenecks to the development of aquaculture production of nontraditional species.
Finfish breeding and hatchery management pdfKartik Mondal
Rivers were the major source of freshwater fish seed in India during 1950’s and 1960’s.
Over the years, the riverine contribution has declined and at present forms only a supplementary source, constituting less than 5% of the country’s total fish seed production.
The Ganga, the Brahmaputra and the Indus river systems in the North and the Peninsular East coast and the West coast river systems in the South are the important natural sources of fish seed.
The transfer of fish seed from the hatchery or place of collection to the rearing pond is called transport of fish seed. The seed fish include fry and fingerlings.
the presentation provides the details regarding the murrels or snakeheads which includes the basic taxonomy, some of the important species, distribution, special characters, its aquaculture potential, food and feeding habits, sexual dimorphism, parental care, age at maturity, the maturity stages, breeding season, courtship and mating, natural spawning, fecundity, induced spawning using ovaprim and HCG and LHRHa, and also the detailed facts regarding larval reariing.
it is about the length and weight relationship of fish , growth, length, weight, absolute growth, isometric growth, relative growth, allometric growth,
Seed production of giant freshwater prawn fisheries pptAshish sahu
Giant freshwater prawn seed production starts in Andaman - INDIA - A scientist and his team of the Division of Fisheries Science, Central Agricultural Research Institute (CARI), Port Blair, have initiated research on breeding and larval rearing of Giant Freshwater Prawn (M Rosenbergii) under controlled conditions at the CARI farm complex.
A short description about magur fish.The walking catfish (Clarias batrachus) is a species of freshwater airbreathing catfish native to Southeast Asia, but also introduced outside its native range where it is considered an invasive species. It is named for its ability to "walk" across dry land, to find food or suitable environments. While it does not truly walk as most bipeds or quadrupeds do, it has the ability to use its pectoral fins to keep it upright as it makes a wiggling motion with snakelike movements.[2] This fish normally lives in slow-moving and often stagnant waters in ponds, swamps, streams and rivers, flooded rice paddies or temporary pools which may dry up
Nutritional requirement of cultivable fin fish: larvae, juveniles and adultsDebiprasad1997
Fish is among the healthiest foods on the planet. It is loaded with important nutrients, such as protein and vitamin D. Fish is also the world's best source of omega-3 fatty acids, which are incredibly important for human body and brain.
Manufactured feeds are an important part of modern commercial aquaculture, providing the balanced nutrition needed by farmed fish.
In the development of modern aquaculture, starting in the 1970s, fishmeal and fish oil were key components of the feeds for these species. They are combined with other ingredients such as vegetable proteins, cereal grains, vitamins and minerals and formed into feed pellets.
The global supply of fish meal and fish oil is finite and fully utilized. Alternative or nontraditional feedstuffs may differ in terms of taste, smell, texture, and color, as well as nutrient composition, from the traditional feedstuffs, which are produced largely from the natural prey of the fish being raised. Alternative feedstuffs may also contain compounds and antinutritional factors that affect digestive or sensory physiology.
Another important area of fish nutrition for the next 20 years will be larval fish nutrition. Currently, the cost and difficulty of rearing a great number of species from the first feeding to the juvenile stage are the most severe bottlenecks to the development of aquaculture production of nontraditional species.
Finfish breeding and hatchery management pdfKartik Mondal
Rivers were the major source of freshwater fish seed in India during 1950’s and 1960’s.
Over the years, the riverine contribution has declined and at present forms only a supplementary source, constituting less than 5% of the country’s total fish seed production.
The Ganga, the Brahmaputra and the Indus river systems in the North and the Peninsular East coast and the West coast river systems in the South are the important natural sources of fish seed.
The transfer of fish seed from the hatchery or place of collection to the rearing pond is called transport of fish seed. The seed fish include fry and fingerlings.
the presentation provides the details regarding the murrels or snakeheads which includes the basic taxonomy, some of the important species, distribution, special characters, its aquaculture potential, food and feeding habits, sexual dimorphism, parental care, age at maturity, the maturity stages, breeding season, courtship and mating, natural spawning, fecundity, induced spawning using ovaprim and HCG and LHRHa, and also the detailed facts regarding larval reariing.
Seed production of Freshwater Prawn.pdfSadia Nabilah
The giant freshwater prawn is the largest and fastest-growing freshwater prawn widely distributed in Indian rivers’ confluent of the sea. The Giant freshwater prawn, M. rosenbergii, has great demand both in national and international markets. It migrates between river and estuary.
crocodiles are the only reptiles having 4 chambered heart,flattened tail and body covered with scutes.hind limb is webbed and in this ppt you can discover all the facts about crocodile..hope you can enjoy
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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.
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.
2. Scientific classification
Kingdom : Animalia
Phylum : Chordata
Class : Actinopterygii
Order : Siluriformes
Family : Clariidae
Genus : Clarias
Species : Clarias batrachus
Scientific name : (Clarias batrachus)
3. Introduction
Magur (Clarias batrachus) is a species of
freshwater airbreathing catfish native to Southeast
Asia.
This fish know as walking catfishe because of its
ability to walk on land by using pactoral fin
movement.
This fish normaly lives in slow moving water body
or in stagnant water like pond, swamps, sreams,
rivers and rice paddies.
4. Geographic distribution
Magur is a very distributed fish species from India
(east India), Pakistan, Bangladesh, Myanmar, Sri
Lanka, Thailand, Singapore, Indonesia, and the
Philippines.
Its current range includes the United States, where
it was first introduced to Florida from Thailand for
cultivation purposes.
5. Biological distribution
This is airbreathing fish. Here accessory breathing
organ is branched and present near the gill.
Can be cultured in oxygen-poor water as it is an
air-breathing fish important.
The head is large and the mouth is present on the
ventral side.
Of the eighth barbels two are much stouter and
larger while others are similar.
6. Cont..
This catfish has long-based dorsal and anal fins, as
well as several pairs of sensory barbels, and also
lacks an adipose fin.
Magur has Pectoral and pelvic fins in paired and
dorsal, anal, and caudal fins in unpaired fins.
The skin is scaleless, but covered with mucus,
which protects the fish when it is out of water.
7. Habits and habitats
This species can be found in freshwater, brackish water,
and terrestrial environments.
It has been recorded at a depth of one meter but the
species’ maximum depth is unknown.
Clarias batrachus burrows into the mud during cold
and dry months to survive poor weather conditions.
Clarias batrachus can survive outside of the water and
travel on land as long as its gills stay moist. It is most
common to see C. batrachus outside of the water after
heavy rains.
8. Feeding habits
The walking catfish is omnivorous
As larvae, C. batrachus feeds entirely on plankton. In the
later developmental stage of fry, it begins to prey on larger
organisms
When it progresses into a juvenile, it predominantly eats
insects
As an adult, a walking catfish preys on plants (benthic
algae), insects (eggs, pupae, or nymphs [e.g., dragonfly
nymphs, chironomid larvae]), aquatic worms, mollusks,
and smaller fish (finfish)
The walking catfish is also a detritivore and eats organic
waste. Clarias batrachus has a broad diet and is known to be
an opportunistic feeder
9. Economic Importance for
Humans: Positive
Clarias batrachus is used in commercial fisheries,
aquaculture, and aquariums
The walking catfish is widely consumed in its
native range (Asia) but not in its introduced range
Further, Ohio and other U.S. states have limited or
prohibited the possession of the walking catfish to
prevent its expansion
10. Economic Importance for
Humans: Negative
The walking catfish poses a threat as an invasive
species
Clarias batrachus, once introduced, is hard to
contain and control due to its mass spawning that
produces several thousands of eggs, its voracious
diet, and its ability to survive in muddy and low-
oxygenated conditions
Costly containment methods, such as the use of
barrier fences, have been utilized to prevent walking
catfish from invading fish stocks
11. Natural breeding of magur
Breeding season:-June-August
Breeding interval :- Walking catfish breed via
multiple spawning cycles during the summer.
Range number of offspring:- 7,000 to 9,000
Average age at sexual or reproductive maturity
(female)1 year, (male)1 year.
Range time to hatching:- 20 to 24 hours
Average time to independence:- 72 hours
12. Cont..
The walking catfish fry becomes independent after
three days
The male guards the nest from predators,
immediately following spawning
The female will return once the eggs have hatched
and the male and female take part in protecting
the fry until they are independent
The parental investment only extends to 24 hours
following the hatching
13. Captive breeding of magur
Breeding techniques : the standard breeding
technique developed by the Central Indian
FisheriesResearch Institute.
Selections of brooder : use Magur one year old
and weighing about 100 g. each.
Identifying brooder : Gravid females are easy to
identify as they are comparatively heavier, have a
round and bulging abdomen and their vent is more
red than that of the males.
14. Cont..
In the female, the genital papilla is short, oval and
slit-like; where as in males, the papilla is conical and
elongated with a pointed reddish tip.
Mature female mature male
15. Cont..
Brood - stock development: brood fish is maintain in
cement tanks with soil and running water.
Stock brooder in well prepared pond in month of April.
Stocking density is 8000 no/ha.
The fishes where fed with trash fishes and rice brand at
9:1 proportions at about 10% of body weight.
Fish meal, wheat flour and soya cack can be also used
in the diet.
17. Cont…
For Induced breeding given singel dose of ovaprim
at same time for both male and female.
Hypodermic syringes with a small size of needle
use to ingect hormones into the muscle of brooder.
Kept the treated male and female fishe sapratly In
two tank.
18. Cont..
Stripping and fertilization: Earlier, the injected males
were sacrificed to prepare sperm suspension in clean
water.
The testes were dissected out and cut into small pieces
with the help of small scissors and a clean blade. A small
amount of water to activate the sperm.
This sperm suspension can remain dormant and fertile for
up to 24 hr.
examined the fish for ovulation by hand stripping.
19. Cont..
Fish that yielded a good stream of transparent green-
brown eggs were rated as ovulated.
released the eggs by gently pressing the abdomen towards
the vent, collecting them on a stainless steel plate.
The sperm suspension was sprinkled evenly over the eggs
and clean water was added.
The milt is then added and mixed well with the help of a
feather.
20. Cont..
Eggs and sperm were allowed to mix by gently moving
the tray for 4-5 minutes.
wash the fertilized eggs thoroughly and transferred them
to the hatchery before the eggs began to adhere. Removed
unfertilized or dead (opaque/white) eggs immediately to
prevent
The developing eggs are small, adhesive, and are
incubated in plastic basins with running water.
fertilized the hand-stripped eggs artificially using the dry
and wet methods.