Transport of hatchlings, fry, and fingerlings is common in aquaculture. Proper techniques involve understanding fish physiology and mortality causes during transport. Seed can be collected from wild or hatcheries. Major carps are collected from flooded rivers during monsoon season. Seed from estuaries and coastal waters include milkfish, mullets, pearlspot, and seabass. Bundhs are seasonal flooded areas that stimulate breeding. Induced spawning techniques breed species that don't spawn in captivity using hormones. Transport uses open or closed oxygenated systems. Factors causing mortality are oxygen depletion, waste accumulation, temperature fluctuations, and stress. Anaesthetics and antibiotics are used to reduce stress and prevent disease.
Carps form the mainstay of aquaculture in India contributing over 85% of the total aquaculture production There are 61,259 species of vertebrates recognized world; over 30,700 are fish species of which 8,411 ore fresh water while 11,650 are marine. In India 2,163 spp. are fin fishes have been recorded from upland cold water (157; 7.26%) warm water of the plain (54; 20.99%), Brackish water (182; 8.41%) and marine environment (1,370; 63.43%). Some of these species are cultured at commercial level which covering a lot varieties of fin fishes The three Indian major carps, namely Catla (Catla catla), Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigal) contribute the bulk of production to the extent of 75 to85 percent of the total fresh water fish production, the three exotic carp such as Silver carp (Hypophthalmichthys molitrix) and Common carp (Cyprinus carpio ), Grass carp (Ctenopharyngodon idella )form the second important group to incorporate several other medium and minor carp and into the carp poly culture system several method were used because of their region specific consumer preference and higher market demand.
History
Carp culture in India was restricted only to a homestead backyard pond activity in west Bengal and Odisha until late 1950 s with seed from riverine sources as the only input resulting low level of production the technological breakthrough breeding of carp through hypophysation in 1957 freshwater aquaculture of the country the country till 1984 virtually laid the foundation of scientific carp farming in the country.
Important characteristics of Indian major carps:-
Indian major carp grow fast and can reproduce even in artificial ponds. They feed upon phytoplankton, zooplankton, decaying organic matter, aquatic plant etc. stomach is absent in the alimentary canal of the major carps. Three types of Indian major carps are cultured in
Carps form the mainstay of aquaculture in India contributing over 85% of the total aquaculture production There are 61,259 species of vertebrates recognized world; over 30,700 are fish species of which 8,411 ore fresh water while 11,650 are marine. In India 2,163 spp. are fin fishes have been recorded from upland cold water (157; 7.26%) warm water of the plain (54; 20.99%), Brackish water (182; 8.41%) and marine environment (1,370; 63.43%). Some of these species are cultured at commercial level which covering a lot varieties of fin fishes The three Indian major carps, namely Catla (Catla catla), Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigal) contribute the bulk of production to the extent of 75 to85 percent of the total fresh water fish production, the three exotic carp such as Silver carp (Hypophthalmichthys molitrix) and Common carp (Cyprinus carpio ), Grass carp (Ctenopharyngodon idella )form the second important group to incorporate several other medium and minor carp and into the carp poly culture system several method were used because of their region specific consumer preference and higher market demand.
History
Carp culture in India was restricted only to a homestead backyard pond activity in west Bengal and Odisha until late 1950 s with seed from riverine sources as the only input resulting low level of production the technological breakthrough breeding of carp through hypophysation in 1957 freshwater aquaculture of the country the country till 1984 virtually laid the foundation of scientific carp farming in the country.
Important characteristics of Indian major carps:-
Indian major carp grow fast and can reproduce even in artificial ponds. They feed upon phytoplankton, zooplankton, decaying organic matter, aquatic plant etc. stomach is absent in the alimentary canal of the major carps. Three types of Indian major carps are cultured in
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries. Fish seed transportation is a process by which transfer of fish seed from the hatchery or place of collection to the rearing ponds.
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.
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
• Fish needs some extra feed
along
with
available
natural feeds in water for
their regular growth.
• This extra feed which are
provided to fish is called
supplementary feed of fish.
Rice bran
•Refined pulse and wheat roughage
•Mustard or sesame cake
•Fish-meal (fish powder)
•Blood and innards of bird or animal
•Green leaves of various vegetables
•Minerals and vitamins
•Kitchen leftovers, etc.
Generalized and specific definition of pond and the types relating their size, use, construction method were illustrated. Besides the culture system of fish and aquatic organisms and their types were also described.
Fish culture is classified based on the number of fish species as monoculture and polyculture. This is the culture of single species of fish in a pond or tank. The culture of trout, tilapia, catfish , carps are typical examples of monoculture.
Seed production and breeding of pearl Oyster &.pptxAbhayBamaniya2
so this presentation includes breeding and seed production of both edible and pearl oyster, which are basically same in a way. note that this does not includes pearl formation in the pearl oyster but after reading this presentation you might learn how to the culture the oyster. good luck! and have fun.
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries. Fish seed transportation is a process by which transfer of fish seed from the hatchery or place of collection to the rearing ponds.
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.
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
• Fish needs some extra feed
along
with
available
natural feeds in water for
their regular growth.
• This extra feed which are
provided to fish is called
supplementary feed of fish.
Rice bran
•Refined pulse and wheat roughage
•Mustard or sesame cake
•Fish-meal (fish powder)
•Blood and innards of bird or animal
•Green leaves of various vegetables
•Minerals and vitamins
•Kitchen leftovers, etc.
Generalized and specific definition of pond and the types relating their size, use, construction method were illustrated. Besides the culture system of fish and aquatic organisms and their types were also described.
Fish culture is classified based on the number of fish species as monoculture and polyculture. This is the culture of single species of fish in a pond or tank. The culture of trout, tilapia, catfish , carps are typical examples of monoculture.
Seed production and breeding of pearl Oyster &.pptxAbhayBamaniya2
so this presentation includes breeding and seed production of both edible and pearl oyster, which are basically same in a way. note that this does not includes pearl formation in the pearl oyster but after reading this presentation you might learn how to the culture the oyster. good luck! and have fun.
This is a presentation about the culture and breeding aspects of Red Sea bream,Pagrus major (Chrysophrys major).This fish have high aquaculture Importance today because of its meat quality and high growth rate
Hill areas offer good scope for the development- of fisheries—both for commercial and sport purposes.
The coldwater fishery resources in India comprise high and mid-altitude lakes, rivers, streams, their tributaries and reservoirs dammed across such rivers.
The importance of coldwater fisheries lies in their unique biodiversity, valuable germplasm and maintenance of environmental quality in hills.
Coldwater fishes breed naturally but since some species have been listed as endangered, therefore artificial breeding is now being practiced to restore the diversity.
Groupers belongs to the family Serranidae.
⚫ Groupers are classified in 14 genera of the subfamily Epinephelinae, which comprises at least half the approximately 449 species in the family Serranidae.
⚫ Several grouper species have been raised on a commercial scale, but mostly by growing out captured wild juveniles.
Shore based aquaculture or coastal brackish water aquaculture is practiced in many countries. There are various methods of traditional culture system based on the local conditions. Shrimp culture is the main attraction of this culture system. Some other fishes and other organisms like crabs, bivalves and seaweeds are also farmed. This type of culture system is mainly found in south East Asia.
Aquaculture (less commonly spelled aquaculture), also known as aquafarming, is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other organisms. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish.
Le diaporama dédié à la culture du milkfish offrira une exploration approfondie des multiples facettes de cette pratique aquacole. En mettant en avant les conditions environnementales optimales, il abordera les techniques de reproduction, les régimes nutritionnels recommandés, ainsi que les défis et avantages inhérents à l'élevage du milkfish. Des visuels graphiques et des images saisissantes seront incorporés pour illustrer de manière vivante le cycle de vie du poisson et dépeindre les installations d'élevage modernes. En parallèle, des données économiques viendront étayer la présentation, mettant en relief l'impact financier de cette activité. L'aspect culturel du milkfish ne sera pas négligé, mettant en lumière son importance dans diverses régions et soulignant son rôle significatif tant sur le plan économique que social. En somme, ce diaporama vise à offrir une compréhension holistique de la culture du milkfish, alliant informations pratiques et perspectives culturelles.
Bottom clean Aquaculture system and It’s Engineering PrincipleDegonto Islam
Bottom clean Aquaculture method is considered an updated version of bio-floc.
The most important tasks here are scientifically removing the waste from the bottom of the reservoir and the rotation of oxygen and food supply to the fishes
In this type of culture system, as the amount of oxygen is higher, it is able to culture fishes 10- 20 times more.
fish population dynamics, Population structureDegonto Islam
Estimation of fish population dynamics are often based on age structures. Understanding past
population structure is of interest to evolutionary biologists because it can reveal when migration
regimes changed in natural populations, thereby pointing to potential environmental factors such as
climate changes as driving evolutionary forces. Characterizing the structure of extent populations is also
key to conservation genetics as translocation or reintroduction decisions must preserve evolutionary
stable units. Finally, population structure has important biomedical consequences either when a number
of subpopulation groups is locally adapted to particular environmental conditions (and maladapted
when exposed to new environments) or represents a confounding factor in the study of the statistical
association between genetic variants and phenotyp
Separation Surplus yield model (MSY, Fmsy, MEY, Fmsy)Degonto Islam
Economic variables are often included in the biological model that suggests the relationship between sustainable revenue, fishing cost and fishing effort.
For more than 50 years, it has been generally accepted that the fishing sector stood to gain from managing fisheries at the effort level producing maximum economic yield rather than maximum sustainable yield, which occurs at a higher effort level.
Surplus production models are also called as Holistic models. This model deals with total stock biomass along with fishing effort and yield. To operate this model, catch and effort data are needed as input data. These models could be computed with less input data unlike analytic models. This model does not take into account age and growth. Hence, it could be safely applied to tropical stocks, where calculation of age of tropical fish is more cumbersome.
Programme planning and evaluation in extension workDegonto Islam
Programme is the total educational job being done in particular settings that forms the basis for extension plan. Programme planning is decision making process which actually analysis the existing condition and matter and evaluation the alternative approach to solve the crux with priorities of the human feeling and needs. Generally initial objectives are peoples participations at grass roots level.
Fishing Gear any form of equipment, implement, tool or mechanical device used to catch, collect or harvest fish. Fishermen in many parts of Bangladesh catch fish with their hands. In rural areas, in seasonal waters or beels, during winter, people can be usually seen fishing with different traditional gears while some even do so without any gear
Guidelines for the control of Aquaculture medicinal products(AMPs)Degonto Islam
Aquaculture drugs and chemicals plays a pivotal role not only in fish health management but also pond construction, soil and water management, enhancement of natural aquatic productivity, feed formulation, manipulation of reproduction, growth promotion and processing. Government of Bangladesh organized an awareness program on control of AMP to create awareness among different stakeholders. Functioning of a control system for AMP is a prerequisite for quality assurance safe fishery products
Present status of Fish Hatchery in BangladeshDegonto Islam
In the past decades the rivers of Bangladesh were the mentor natural source of carp seed production. Due to the destruction of natural habitats and also increase demand the natural available of carp seed has largely declined and the aquaculture venture and gradually replaced by the hatchery produced fry since early 80’s when artificial fish breeding technique and low cost hatchery design have been successful adapted in Bangladesh.
This world have numerous kinds and diversity .This kinds and diversity remain in whole world two two third is aquatic ,fresh water and marine water .This kinds and diversites knowledge and their total knowledge file management is very importance for fisheries science.
This freshwater and marine water has a huge number of vertebrate and invertebrate animals and plants. Thair identify and use is vary importance for fisheries and aquaculture .for that their proper file management is play a useful role in fisheries and aquaculture.
If we went to know the total plant and animals this is not possible to proper file management.
Culturable species and there predator knowledge and file management is vary importance for aquaculture .culturable species habitats and their food habit is very importance for successful aquaculture and also importance in breeding season and behavior and high growth rate fish data .There proper management and for fisheries student study documents is very important. So file management is very importance in fisheries science.
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.
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.
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.
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 entangled aventures in wonderlandRichard 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.
1. 1
Introduction: Transport of hatchlings, fry and fingerlings of culturable species is a common
necessity in aquaculture. Often large adult breeders have also to be transported for facilitating seed
production. Recently improvements have been made in the techniques of live fish transport with the
knowledge of the basic physiological requirements of fishes in different stages of their life history
(hatchling, fry, fingerlings, juveniles and adults) and also of the causes of mortality of fishes during
transport.
The collection of seeds from the wild is the main source to obtain the stocking material. This can be
carried out when the seed production cost is very high or where the availability of seed from nature is
in large quantity. It is imperative to have a sound understanding of the biology of the fish species to
know when and where to collect the fish. These fish seed can be captured from wild or from
hatcheries.
Natural fish seed collection
In various countries, pond breeding species are generally preferred for fish culture as they do not
involve the difficulties in the collection and transportation of young fish. But the widely cultured
species of carps reputed for their very fast growth and culture conditions do not ordinarily breed in
ponds and as such their young ones have necessarily to be collected mainly from the flooded rivers
where these carps spawn annually during-the short monsoon season. Certain fast growing fish seed are
easily available in the wild.
Halda River is the only tidal river in the world, has been reported to
server as a natural source of fertilized carp eggs. The results reveal
the local eggs collectors of Halda river collect carp eggs from May-
July and hatch the by their indigenous hatching techniques. After 4-
5 days of hatching, egg collectors start to sell the fry to fish farmers
from different nooks of Bangladesh at the rate of BDT 40,000-60,000
kg–1
The cultivable marine fin fish seed resources such as Milkfish, (Chanos chanos), Grey mullets,
(Mugil cephalus, Liza parsia, Liza tade, Liza cunnesius, Liza vaigiensis and Valamugil seheli),
Pearlspot, (Etroplus suratensis), Sandwhitting (Sillago sihama), Rabbitfish (Siganus javus,
Figure 1 Egg collection from halda
river
2. 2
S.canaliculates), Seabass (Lates calcarifer), Grouper, (Epinephelus tauvina, E.hexagonatus), and
Seabream (Lethrinus spp.) are available from estuaries, brackish waters and coastal waters of India.
Collection of fish seed from the wild differ with species to species. Grey mullet seed is abundant from
October- February, where as other Grey mullets (L. macrolepis, L. parsia, L. tade, L. cunnesius, L.
vaigiensis and V. seheli), occur throughout the year. The fry and fingerlings seabass occur from
October-February and May-September. The fish seed is collected through local fishermen using
local fishing crafts
and gears.
Bundh spawning
In the confined waters of ponds Indian major carp do mature but do not breed. If these matured
breeders are transferred from confined waters to semi-confined rain-fed ponds, where the pond bottom
is of muddy nature, the fish breeds whenever there is a good rainfall and a drop in temperature of
water. The semi confined rain-fed seasonal water bodies have more dissolved oxygen, light, waves,
water current and turbidity, and less temperature, which stimulate ovulation. Based on the above
factors, the places where excess of rain water is used in creating riverine conditions, which stimulate
ovulation in fishes, are known as bundhs. The bundhs are suitable places in producing fish seed.
Types of bundhs : The bundhs are of two types:
Wet bundhs: These are also known as ‘perennial bundhs’.
During summer, only the deeper portion of the pond retains water
containing breeders. The remaining portion is dry and is used for
agriculture. After a heavy rain a major portion of the bundh gets
submerged with water flowing in the form of streamlets from the
catchment area and excess water flows out through the outlet. The
fish starts spawning in such a stimulated natural condition in the
shallow areas of a bundh.
Dry bundhs: A dry bundh is a shallow depression enclosed by
an earthen wall, which is locally known as a bundh. on three sides,
and an extensive catchment area on the fourth. Bundhs get flooded
during the monsoon, but remain completely dry for a considerable
Figure 2 Wet bundh
Figure 3 Dry bundh
3. 3
period during the remaining part of the year. Bundh breeding being practiced since a century has been
given a greater importance. The contribution of spawn production from bundhs is quite significant,
particularly the spawn from dry bundhs as this source yields 100% pure spawn. It is known for its
simplicity and mass production at one time.
Management of Bundh breeding: The efficiency of the bundhs depends on many factors. The
following criteria may be kept in mind when designing bundhs for fish breeding.
1. Extensive upland area from where, with heavy rains, considerable amount of rain water carrying
soil and detritus enters the main pond.
2. The pond should have extensive shallow marginal areas which serve as ideal spawning grounds.
3. The soil should be of gritty nature which is considered to be the most suitable for the breeding of
fishes.
4. Increase in oxygen contents of water which is due to the vast and shallow area of the pond.
Induced spawning
Induced breeding is a technique by which the economically important fish (which generally. do not
breed in captive condition) are bred through artificial stimulation. Induced breeding is
a technique where by ripe fish breeders are stimulated by pituitary hormone or any other.
Natural fish populations have declined during the last several
decades because of environmental degradation and over-fishing.
This has resulted in an increased effort in the development of
techniques for hatchery production of fish. Traditional
aquaculture species such as trout, catfish, common carp, golden
shiner, and goldfish reach sexual maturity and spawn in hatcheries or ponds, when conditions are
appropriate. However, a number of fish species that have or potentially have great economic
significance for aquaculture do not reproduce spontaneously in captivity. Many of these fish spawn in
environments that are nearly impossible to simulate in a hatchery. Hormone-induced spawning is the
only reliable method to induce reproduction in these fishes Surprisingly, the same procedures, with
only minor modifications, have been used to spawn an entire range of fishes from the ancient
4. 4
sturgeon and paddlefish to carp, catfish, salmon, sea bass, redfish, snook, and mullet. In addition
to breeding other desirable fish species, induced spawning can be used to:
1) Produce hybrids that are different from the parent species;
2) Produce sterile polyploid fish (for example, sterile triploid grass carp for aquatic weed control);
3) Synchronize reproduction of large numbers of fish for simultaneous spawning, thereby
simplifying production and marketing of the fish;
4) Produce fry outside the normal spawning season for maximum hatchery production and to
provide fish when the price and market demand is greatest; and
5) Maximize survival of fry under controlled hatchery conditions.
Method of packing and transportation of fry and live fish
Transport carriers are of two types: (a) open system comprising open carriers, with or without artificial
aeration/oxygenation/water circulation and (b) closed system having sealed air tight carriers with
oxygen.
Open system: The simplest transport carrier is the earthern vessel, such as the traditional “Hundi”
used in Bengal in India. The earthern hundi is now being replaced by aluminium vessels which are
unbreakable, but the earthern hundies have the advantage that they keep the temperature of the water
inside cool by means of evaporative cooling. The earthern vessels are filled with water of the same
source as that of the fry. About 50,000 carp spawn are released in the small vessel and 75,000 in the
larger, During transport, the bottom sediments are periodically removed by mopping them up with a
rough cloth rope - the water is also partially renewed depending on the need. The addition of red soil
and change of water permit transport of fry up to a duration of 30 hours. Besides pulverised earth other
absorbant substances such as activated charcoal and ‘Amberlit’ resin can be also used as these
absorb carbon dioxide, ammonia and other substances from the medium
Closed system: In this system the water surface is exposed to compressed air or pure oxygen
introduced to fill the zone over the water surface in the carriers which are sealed air-tight .Sealed metal
5. 5
containers, rubber and plastic bags have been used for the purpose. In a metal container of galvanized
iron (45 × 35 × 35 cm) with two airtight openings, one to let in oxygen and other to let out water, 100
– 200 fingerlings of 7 – 10 cm, or 30 – 40 fingerlings of 13 – 20cm length, can be transported for a
journey of 12 hours. Eighteen litre tins with airtight screw-capped lids for filling and provided with
tubes for drawing in oxygen and letting out water, have been used in CIFRI, Barrackpore, for
transporting 1000 fry of 1 – 2 cm length during a 20-hour journey.
Transportation of seed: In order to ensure the good survival rate after releasing in the pond, it is
necessary to communicate to hatchery authorities. So that, it is able to modify the water parameter at the
nursery stage itself. i.e.,starving one day early to avoid excreting the faecal matter. This is called
6. 6
as "Conditioning of fish". Reduce the temperature to minimize the metabolic rate and oxygen
consumption..
Some Important Tips for Transportation of Fish : Transportation early in the morning is better (Cool
Hour).The water used in transportation should be cool and clean. Number of fish seeds per transportation
unit should be maintained, over number may lead to death of fishes. The number of fish seeds to be
packed in a bag can be calculated using the below mentioned formula.
N = (DO – 2) x V Where, N = Number of fish seeds
C x h DO = Dissolved oxygen
V = Volume of water in 1 liter
C = Rate of oxygen consumption by
Individual in mg / kg / hour
h = Period of transportation in hour
Oxygen packing is the best method of transportation. Anaesthetics can be used while transportation to
minimize the metabolic activities of the fish seeds. Thereby, excretion of the nitrogenous compounds
can be avoided.
Care should be taken so that no direct sunlight falls in the packing bags during transportation.
The seed packing bags should be covered with the wet gunny bags. So that, temperature of the
seed packing bags will be maintained low.
If the transporting distance is long, glucose powder can be added to the seed packing bags.
To remove the toxic ammonia from the media to safeguard the seedlings from the mortality,
the absorbent is added which can reduce 50 % of ammonia for 24 hours transportation.
Sodium Phosphate – 2g/l is used as buffer.
Cause of mortality of fry and brood fish during transportation
The factors responsible for mortality of fish seed during transportation includes
1. Depletion of dissolved oxygen in ambient water due to respiration by fish and also due to
oxidation of any organic matter (BOD load), including excreted waste of the fish, by micro-
organisms.
2. Accumulation of free carbon dioxide (CO2) resulting from respiration and ammonia (NH3)
as excretory end product.
7. 7
3. Sudden fluctuations in temperature.
4. Hyperactivity and stress due to handling and ‘confined space’
5. Ion-osmotic imbalance due to stress.
6. Physical injury due to handling before transport and during transport and Diseases.
Use of antiseptics and antibiotics in live fish transport
Drugs and chemicals are either used as tranquilizers and sedatives or as antiseptics and antibiotics.
General listing of anaesthetics for fish has been given by several workers Sedatives are generally used
for:
i. Reducing metabolic rates, mainly oxygen consumption and excretion of carbon dioxide and
ammonia.
ii. Reducing excitability of fish and injury, and
iii. Convenience in handling fish.
The sedatives and drugs have to be used very carefully, for slight increase in dosage and/or exposure
time can cause irretrievable loss of fish.
Table 1Behavioural responses of fishes in relation to different levels of anaesthesia
Definite levels of anaesthesia Behavioural response of fish
Stages 0 Normal Reactive to external stimuli equilibrium and
muscle tone normal
I (1) Light sedation Slight loss in reactivity to external stimuli (visual
& tactile)
I (2) Deep sedation Total loss in reactivity to external stimuli except
strong pressure, slight decrease in opercular rate.
II (1) Partial loss of equilibrium
(2) Total loss of equilibrium
Partial loss of muscle tone, react only to very
strong tactile and vibrational stimuli, rheotaxis
present, but swimming capacities seriously
disrupted, increased opercular rate.
III Loss of reflex Total loss of muscle tone, react only to deep
pressure stimuli, decreased opercular rate - below
8. 8
normal.
IV Medullary collapse Respiratory movements cease, followed several
minutes later by cardiac collapse.
As already referred to, fish anaesthetized properly can be carried without water, provided the skin and
gills are kept moist, and the ambient temperature is cold. Commonly used chemicals and their doses
are indicated below
Methylene blue - 2 ppm
Acriflavin - 10 ppm
Chloromycetin - 8–10 ppm
Copper sulphate - 0.5 ppm
Sodium chloride - 3%
Potassium permaganate
- 3 ppm
A prophylactic bath of fry and fingerlings in the above mentioned chemicals is recommended while
handling the fish prior to transport, for prevention and spread of diseases - pathogens and parasites.
Conclusion
Modern developments in transport technology are from two levels; one is from an understanding of
internal physiological mechanisms of the fish and the optimal requirements, ensuring maximum
survival of fish under transport and the other is from a study of the environmental parameters of the
medium in which fish are transported. Under anaesthesia fish can be transported without water even,
provided the skin and gills are kept moist under low temperature. The cryopreservation of fish sperm
for use at any convenient time can be referred to here, though this would concern seed production
more directly than live seed transport.
Reference
1) http://eprints.cmfri.org.in/10186/
2) http://www.fao.org/3/T0555E/T0555E08.htm
3) http://agrilife.org/fisheries/files/2013/09/SRAC-Publication-No.-421-Introduction-to-
Hormone-Induced-Spawning-of-Fish.pdf
4) https://fisheries.tamu.edu/aquaculture/induced-spawning/
5) http://www.fao.org/3/ac182e/AC182E04.htm