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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

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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

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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

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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

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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

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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.

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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

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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