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

1. VISHNURAJ R.S
DEPT. AQUATIC BIOLOGY
AND FISHERIES
UNIVERSITY OF KERALA

2.  Red seabream, Pagrus major (Temminck and Schlegel, 1843) is a
demersal species that occurs in the northwest Pacific (the northeastern
part of the South China Sea northward towards Japan) at depths between
10 and 50 m.
 The red sea bream, Pagrus major (Chrysophrys major), is the most
valuable marine fish in Japan.
 A first trial to culture it has been made at a hatchery located at Seto
Inland Sea coast in 1902 (KAJIYAMA, 1937). The hatchery was soon
closed because of difficulty in rearing the larvae.
 SHlKAMA, YMASHITA and NISHIZUKA succeeded in rearing 22 red
sea bream fry from the eggs for the first time in Japan in 1962
(YAMASHITA, 1967).
 These successes were achieved on an experimental scale, and therefore,
further experimentation was necessary before developing mass
production methods.

3.  1967, NOGUCHI observed natural spawning' of cultured red sea breams in
a large tank at Naruto Aquarium, Tokushima, Japan+ (NOGUCHI, 1968).
 Based on these successes, research has been carried out in order to find a
mass rearing method for red sea bream larvae at the hatcheries belonging to
Seto Inland Sea Fish Farming Association (ANONYMOUS, 1974).Most
sparid species have been used in mariculture and cultivated in cages.
CLASSIFICATION AND CHARACTERS
Kingdom: Animalia (animals)
Phylum: Chordata (chordates)
Subphylum: Vertebrata (vertebrates)
Superclass: Gnathostomata (jawed vertebrates)
Class: Actinopterygii (ray-finned fishes)
Order: Perciformes
Family: Sparidae
Genus: Pagrus
Species: Pagrus major

4. The family Sparidae contains 35 genera and112 species, distributed
mainly in tropical and temperate waters of the Atlantic, Pacific and
Indian oceans (Froese and Pauly, 2005).
Eighteen of these species inhabit the Adriatic continental shelf (Jardas,
1996). Two of these belong to the genus Pagrus (Cuvier, 1816): Pagrus
pagrus (Linnaeus, 1758) and Pagrus coeruleostictus (Valenciennes,
1830).

5. DISCRIPTION
 Body robust, oblong, moderately compressed. Upper profile of head convex
with a bulge above eye.
 Lower jaw slightly shorter then upper. Head and upper body dark violet,
sides and belly silvery. Several small bright blue spots on upper sides.
 All spines of dorsal fin tough and not elongated.
 Caudal fin forked with pointed lobes. Scales moderately large, absent from
bases of soft dorsal and anal fins. Posterior margin of caudal fin black, lower
margin white.
 Dorsal spines (total): 12; Dorsal soft rays (total): 10; Anal spines:
3; Anal soft rays: 8.
 Body with many bluish dots when fresh. Shallow body, body depth 2 or
more in SL.
 Transverse scales 6.5-7.5. All spines of dorsal fin are tough and not
elongated. Posterior margin of caudal fin black, lower margin is white.
 Occurs from 10 to 50 m depths, often on rough grounds, but also on softer
bottoms.

6. NATURAL DISTRIBUTION
They are mainly distributed in Northwest Pacific: northeastern part of South
China Sea (Philippines excluded) northward to Japan.
HATCHERY DESIGN
The basic considerations in establishing a fish hatchery are: (i) which
site is suitable, (ii) what is the area of the site and the facilities required
in relation to the goals or objectives of the hatchery, and (iii) how will
the hatchery be managed.

7.  It is of primary importance to conduct a feasibility study to determine the suitability
of the site.
 This should be done prior to the establishment of the hatchery. There are three
factors which must be considered in designing a fish hatchery:
 (i) species,
 (ii) production target, and
 (iii) level of financial input.
In addition, the facility requirements will depend on the nature of organization to
run the hatchery.
For government pilot projects, some laboratory support facilities are required.
Criteria in the selection of sites for seabream hatchery
1. Seawater supply
The seawater used in a hatchery should be clean, clear and relatively free
from silt. The water quality should be good with minimal fluctuation in
salinity all year round. Suitable sites are usually found near sandy or rocky
shore. Sites which are not suitable for hatchery include areas which are
heavily influenced by rain or turbulence.
An added advantage of having a site on rocky shores is that good quality
seawater is relatively near the shoreline. This reduces the cost of piping
installation and pumping. The hatchery site should also be free from any
inland water discharges containing agricultural or industrial wastes.

8. 2. Accessibility
Ideally, a hatchery site should be selected in areas where there are active fish
farming operations so that the fish larvae produced can be easily transported
and distributed to the grow-out ponds and cages. The site chosen for a
hatchery must have easy access to communication and transportation
channels.
3. Availability of power source
A fish hatchery cannot be operated without electricity. Electricity is essential
to provide the necessary power to run the equipment and other life support
systems of the hatchery.
4. Topography
The ideal site should be spacious, situated on flat to gently sloping grounds,
well drained and not susceptible to floods, strong wave and tidal actions.
5. Acquisition
It is advisable to pay attention to land values early in the site selection
phase to ensure that the site is available for purchase or lease and at a price
consistent with the project budget.

9.  Hatchery size
 Hatchery design is aimed at achieving certain production targets which in
turn determine the size of the hatchery.
 The capacity is based on an approximate ratio between tank for production
of natural food (algae and rotifer) and larval rearing tank.
 The spawning tank depends on the larval requirement which is based on the
number of spawners.
SEAWATER SYSTEM
 Seawater can be drawn directly from the sea or from the sump pit.
 If the source of water is relatively clear, the water can be pumped directly
into the overhead filter tank and stored in the reservoir or storage tank.
 if the water is turbid and contains a high concentration of suspended solids,
it must be pumped first into a sedimentation tank where the suspended
solids are allowed to settle down
Holding tanks
 The holding tanks in the seabream hatchery are used for various purposes
such as for brood stock conditioning and subsequent spawning, incubation,
larval rearing and production of natural food.

10.  A brood stock development/spawning tanks

11.  An incubation tank.

12.  A larval rearing tank.

13. SPAWNING AND HATCHING
Maturation
 The red sea breams used for spawning are kept in net cages or concrete
tanks
 (Dimensions: 10-20 m x 10 m x 5 m), for about a year or two depending
on their initial ages.
 The red sea bream becomes sexually mature when 3 years old.
 The spawning season extends from April to June, with a peak in early
May.
Brood stock development
 There are two sources of seabream brood stock: wild-caught adults and
from ponds/cages (2–6 years old fishes averaging in weight from 3 to 5
kg).
 It is advantageous to use pond or cage-reared brood stock as they are
already used to culture conditions being easier to condition and develop
them into brood fish.

14. 1. Wild brood stock collection
 The fishery worker must constantly strive to minimize stress in handling
captive brood stock.
 Efforts to capture seabream should be confined to areas where they are
known to occur.
 The selection of a suitable gear or method of capture must also be
considered.
2. Conditioning of wild brood stock
 Captured fish are placed immediately in transport tanks and taken directly to
the hatchery or holding cages.
 Anesthetic is not necessary if the fish are shipped in live tanks or in aerated
transport containers.
 Upon arrival at the hatchery, the fish are treated with antibiotic such as
oxytetracycline.
 2 ppm for the dripping method for 24 hours and 20 mg per 1 kilogram of
fish for the injection method.
 In nature, seabream is a carnivorous and feeds voraciously on live fish.
However, in captivity, they can be conditioned to feed on dead fish.

15.  The uneaten feed should be removed to prevent water pollution.
3. Brood stock maintenance
 The fish, whether cultivated or wild-caught, can be maintained as brood
stock in cages and concrete tanks.
 (a) Cages
 Floating cages are usually used for brood stock development.
 The size of the cages varies from 10 to 100 sq.m in surface area with a depth
of 2 meters (dimension: 5 × 5 × 2m or 10 × 10 × 2m).
 Smaller cages are more suitable because they are easier to maintain and
manage (such as in changing of net and harvesting).
 The mesh size of a brood stock cage varies from 4–8 cm. Stocking density
of fish is 1 per cubic meter of water.
 (b) Concrete tanks
 The size of concrete tanks used for holding brood stock depends on the size
of the hatchery. It is advisable to use a bigger tank to allow the fish ample
space for swimming.
 Generally, tank volume ranges from 100–200 tons (5 × 10 × 2m and 10 × 10
× 2m). Stocking rate in brood stock tank is 1 fish for every 2 cubic meters of
water.

16. Spawning and fertilization
1. Selection of spawners
 The selection of spawners from the brood stock should be done months
before the beginning of natural spawning to allow ample time for the fish to
be conditioned to environmental and diet controls. Spawners are normally
selected based on the following criteria:
 fish should be active
 fins and scales should be complete
 free from disease and parasite
 free from injury or wounds
 males and females of similar size groups are preferred
 spawner should be at least 4–5 kg in body weight and should not be less
than 3 years old
 Selected spawners are then transferred to the pre-spawning tank. The ratio of
male and female stocked in the pre-spawning tank is 1:1.

17. 2 .Care of spawners in pre-spawning tank
 Immediately after stocking in the pre-spawning tank, the feeding is reduced
from 5% to 1% of the total body weight and fed once a day.
 This is to prevent the fish from getting fat which can result in poor gonadal
development.
 The feed given should be fresh marine fishes such as sardine, yellow stripe
thread fin, etc.
 Water in the spawning tank should be maintained in good condition. This
can be achieved by changing the water about 50–60% daily.
Spawning of seabream
 Presently, there are two major techniques employed in mass production of
seabream fry in Southeast Asian countries: artificial fertilization and induced
spawning.
1 .Artificial fertilization.
 Spawners are caught in natural spawning grounds near the mouth of the
river or in salt water lakes, where the water depth is about 10–20m.

18.  The degree of maturity of the collected spawners should be immediately
checked.
 If the female has ripe eggs and the male is in the running stage, stripping is
done in the boat. The fertilized eggs can then be transported to the hatchery
for subsequent hatching.
 In cases where only the male is caught, the milt is collected by stripping into
a dry glass container.
 Milt is then stored in an ice box or refrigerator. The milt can maintain its
viability after a week in cold storage (5–15°C).
 The preserved milt should be made available for immediate use when a ripe
female is caught. The dry method of fertilization is normally used in this
case.
 The eggs are stripped directly from the female to a dry and clean container
where the milt is added.
 A feather is used in mixing the milt and eggs for about 5 minutes. Filtered
seawater is then added into the mixture while stirring it and then allowed to
stand undisturbed for 5 minutes.

19. 2. Induced spawning
 Two methods are normally used for inducing seabream to spawn in
captivity, e.g. hormonal injection and environmental manipulation. Both
methods would induce the fish to spawn naturally in the tank. This results in
a monthly spawning until the gonads are spent.
2.1, Induced spawning by hormone injection
 After stocking seabream brood stock in the pre-spawning tank for two
months, the fish are inspected twice a month during spring tide, ovarian
maturity of the female is measured as follows: the eggs are sampled from
the female through the use of a polyethylene cannula of 1.2 mm in diameter.
 The fish is either anaesthetized or inverted gently with a black hood over the
head. The cannula is inserted into the oviduct for a distance of 6–7- cm from
the cloaca.
 Eggs are sucked orally into the tube by the operator as the cannula is
withdrawn. The eggs are then removed from the cannula and egg diameter
measurement is made.

20.  When the seabream eggs reach the tertiary yolk globule stage or have a
diameter of 0.4–0.5 mm, the female is ready for hormone injection. In
males, only those with running milt are chosen.
 The hormones usually used to induce spawning in seabream that produce
reliable results are:
 Puberogen
 HCG + pituitary gland of Chinese carp
 Puberogen consists of 63% follicle stimulating hormone (FSH) and 34%
Leutinizing hormone (LH). The dosage usually applied is 50–200 IU/kg of
fish.
 The fish will spawn at about 36 hours after injection. If no spawning occurs,
the second injection is applied 48 hours after the first injection.
 The dosages of second injection should be double from that of the first
injection and can also be given 24 hours after the initial injection.
 The male is usually injected at the same time as the female with a dosage of
20–50 IU/kg of fish. The fish will normally spawn within 12–15 hours after
the second injection.

21.  Homogenized pituitary glands of Chinese carp are used at 2–3 mg/kg of fish
mixed with Human Chorionic Gonadotropin (HCG) at 250–1,000 IU/kg of
fish.
 The time interval of application and spawning are the same when using
puberogen .
2.2 Induced spawning by environmental manipulation
 Based on field observations and analysis of natural phenomena that occur
during spawning period of seabream, techniques were developed to
stimulate the fish to spawn in captivity. The following steps are necessary:
 changing the water salinity to simulate fish migration
 decreasing the water temperature to simulate the decreased water
temperature after rain
 lowering and subsequent addition of fresh seawater to the tank in order to
simulate the rising tide, and
 Follow the moon phase.

22.  Initially, the salinity of water in pre-spawning tank is prepared at 20–25 ppt
before stocking the selected spawners.
 After stocking, 50–60% of water is changed daily until 30–32 ppt is
reached. This will take about 2 weeks.
 This will simulate the migration of fish from its growing grounds to the
spawning grounds.
 At the beginning of the new moon or full moon, the water temperature in the
spawning tank is manipulated by reducing the water level in the tank to 30
cm deep at noon time and exposing to the sun for 2–3 hours.
 This procedure increases water temperature in the spawning tank to 31–
32°C.
 Filtered seawater is then rapidly added to the tank to simulate the rising
tide. In effect, the water temperature is drastically decreased to 27–28°C.
 The fish spawn immediately the night after manipulation (1800–2000 hours)
or if no spawning occurs, manipulation is repeated for 2–3 more days.

23. Egg collection and incubation
 Fertilized eggs of seabream range in size from 0.8–1 mm. They float in
the water column (pelagic) and are very transparent.
Eggs in spawning tank can be collected and transferred to incubation tanks
by either of the following procedures:
 The spawning tanks are supplied with continuous flow of seawater. The
overflowing water carry the eggs into a small tank (2 × 0.4 × 0.3 m)
containing a plankton net (200μ mesh).
 Eggs are collected and transferred to larval rearing tanks the following
morning.
 The eggs are collected from the spawning tanks using a fine mesh (200μ)
seine net the morning after spawning.
 Fertilized eggs are then transferred to incubation tank at the density of
100 eggs/liter.
 The eggs will hatch at about 17–18 hours at 26–28°C after spawning.
Dead eggs which settled at the bottom are removed by siphoning.

24.  Hatching rate of seabream eggs by environmental and hormonal
manipulation ranges between 40–85% and 0.1–85%, respectively.
Larval rearing
 The rearing tanks are commonly fabricated from plastic, fiberglass, wood
or concrete. A typical larval rearing tank is rectangular in shape and
located outdoor. Its volume ranges from 8–10 tons (7 × 1.2 × 1m or 10 ×
1.5 × 1m).
 The tanks are usually protected from strong sunshine and heavy rains by
a roof tile cover
 The usual stocking density for newly-hatched larvae in rearing tank is
between 50–100 larvae/liter.

27. REARING THE LARVAE
Prelarval stage
 The newly hatched larvae are introduced into floating tanks (dimensions:
about2-4 m x 2-4 m x 1.5-2 m) made of synthetic fiber cloths.
 The floating tanks are hanged in a large concrete tank (water volume: 50-
200 m3).
 The survival rates of pre larvae are improved in tanks with abundant
propagation of uni-cellular green algae.
 In order to promote the propagation of uni-cellular green algae, small
amounts of inorganic and organic nutrients are added into the floating tank.
 The optimum density of uni-cellular green algae is about 300,000 cells/ml.
 Slight aeration is provided by about 8 vinyl hoses (diameter: 5 mm) per
floating tank.

28.  The pre larvae are released into large concrete tanks after they have been
reared for about 10 days in the floating tanks.
 The daily rate of water renewal is set to 1/4 of the total volume several days
before transferring the larvae to another rearing net cage.
 Waste accumulated on the bottom is removed by siphoning.
 The newly hatched larvae live for the initial 3 days on their yolk sac.
 The actual feeding begins on the 4th day after hatching, when the yolk sac
is resorbed and the digestive organ is formed.
 Oyster eggs, rotifers (Braahionus pliaatilis), copepods collected by net, and
nauplius of Artemia salinaare used for feeding individuals in pre larval
stage.
 Copepods seem to be a better food than Artemia.
 Maximum initial density of pre larvae was 25000/m3 while the density at
harvest was 2000/m3.
 Average survival rate at pre larval stage was 10 % Pre larvae hatch at 2.0-2.3
mm total length. They grow to about 6 mm total length in 20days.

29. POST LARVAL STAGE
 Post larvae of red sea bream (about 6 mm in total length) are transferred into
net cages installed at sea.
 The water depth of the large concrete tanks is decreased to 1/3 (water
volume: 50 m3) before gathering the larvae in order to avoid injury due to
water current.
 The nets are cleaned every 2-3 days and replaced every 5 to 10 days. Post
larvae are cultured to fry stage (20-30 mm total length) in the net cages for
about l0-40days.
 Initial density of post larvae in the net cages is about 2.000/m3.
 The number of fry harvested is about 400-500/m3. Survival rate during net
cage stage is about 30 %.
 Survival rate of fry from hatching to 20 mm total length is about 3 %.
 Feeding with Braohionus plieatilisand Artemia salinais preferable at the
early stage of the net cages.
 But the main feed used during the net cage stage is trash shrimp and fish
flesh.

30. The factors affecting the hatching rate
Water temperature:
 The fertilized eggs cease to develop at morula stage at 10° C. The hatching
rate becomes poorer and mortality increases at 25° C. The optimum
incubation temperature ranges from 15.0 to 17.5° C.
Specific gravity:
 The fertilized eggs float at the water surface when its specific gravity is
higher than 1.023. They sink under the middle layer when the specific
gravity is lower thanl.023. The hatching rate is 80-98 % for the former case
and 20-50 % for the latter.
Turbidity due to mud:
 The effect on the hatching rates of 50 ppm silt in the water is not detectable.
 However a decrease in hatching rates' is noticeable at l00 ppm.
Mechanical shocks:
 It is important to avoid mechanical shocks such as disturbance and
vibration, as much as possible, when gathering and transferring the eggs.

31.  Red seabream, Pagrus major (Temminck and Schlegel, 1843) is a
demersal species that occurs in the northwest Pacific (the northeastern
part of the South China Sea northward towards Japan) at depths
between 10 and 50 m.
 The red sea bream, Pagrus major (Chrysophrys major), is one of the
most valuable marine fish in Japan.
 This is one of the fish used in aquaculture, and in India its aquaculture
practice is not much developed.
 The seeds producing in artificial way is to be more difficult because
of its less survival capacity.
 But in artificial way also seed produced, that is by induced method
and environmental manipulation.

32. THANK YOU