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SHIBAM SAHA M.F.SC, DEPT OF FRMMATER’S SEMINAR
2015-2017
BREEDING AND REARING METHODS OF THE COMMERCIALLY IMPORTANT SPECIES
Trichogaster lalius (DWARF GOURAMI)
CREDIT SEMINAR ON
WESTBENGAL UNIVERSITY OF ANIMAL AND FISHERY SCIENCES
INTRODUCTIONAn Ornamental fish usually mean attractive,colourful fishes, which are kept as pets in
confined space of an aquarium or a garden pool for fun and fancy.
(Mils,1990 and Dey,1996)
They are also known as living jewels for their bright, brilliant and beautiful coloration
and shape.Besides their coloration some peculiar characteristics such as morphology,
mode of taking food etc, may also add to their attractiveness. (Dey,1996)
These ornamental fishes are preferred to be kept in aquarium and thus termed as
“aquarium fish”. They form an important commercial component of fisheries, providing
aesthetic requirements and un keep the environment. (Class note; Dr. T.K Ghosh)
“An ornamental fish means a generic term to describe aquatic animals kept in aquarium
hobby, including fishes, invertebrates' such as corals, crustaceans (eg. Crabs, hermit
crab, shrimp) mollusks(snails, scallops,clams) and also live rock”------------
(Liven goods and champman,2007)
WHY SHOULD WE KEEP ORNAMENTAL FISHES?Keeping ornamental fishes as pets prove advantageous to us in several ways:
a) Keeping ornamental fishes as pets in home aquaria or garden pools gives
pleasure to the young and the old alike.
b) Keeping ornamental fishes have many advantages over other pets.
c)Relaxation of mind, particularly when we feel tired or depressed.
d) The hobby opportunity to watch the behavior of these tiny creatures from
close quarters and develops a sense of attachment with nature.
e) Ornamental fishes kept in an aquarium or garden pool become an attractive
focal point and add to the aesthetic beauty of the home and its surroundings.
f) The hobby of keeping ornamental fishes can be groomed as a source of self
–employment by taking to various types of ancillary.
ORIGIN OF KEEPING ORNAMENTAL FISHES AS PETS:
Aquarium keeping as hobby was started several hundred years ago in eastern china. The ancient Rome was the first to keep ornamental fishes as pets at home. It has been realized that aquarium keeping is not only means of recreation but also a source of earning.(Ayyappan;2006).Aquarium keeping of fish began in 1805 with the first public display aquarium opened at Regent’s park in England in1853.As the days passed it become an interesting activity for many in the process of generating income for the unemployed youth and farmers.(Ayyappan;2006)In India, the hobby of keeping ornamental fishes bloomed with the opening of the “TARAPOREVALA” aquarium in Mumbai in 1951 and also several aquarium societies in the city.
In West-Bengal, a persistent drift from villages to the urban areas for job and more income has resulted in the over crowding in cities and loss of man power in rural areas. (Ray;1994)In such condition breeding and culture of ornamental fishes is an attractive alternatives to cheek such drift and it can improve rural economy.(Das,Chattopadhyay;2003)
STATISTICAL OVERVIEW : GLOBALLY
According to National Fisheries Development Board(NFDB) report,2014-15 the ornamental fish trade with a turn over of US $ 6 Billion with an growth rate of 8%.More than 2500 species are traded and some 30-35 species of fresh water fish dominate the market. More than 90% of fresh water fish are captive breed and out of 8000 marine ornamental, only 25% are breed in captivity .The top exporter country is Singapore(19.8%)followed by Japan(7.4%),Malaysia(7.3%), Indonesia(5.3%),Israel(4.3%),Thiland(3.9%),Srilanka(2.9%)and India(0.008%).Singapore is the largest exporter for many years and regarded as a major trade hubs of ornamental fish in this region. (Anon;2010) About 120 countries import ornamental fish. The major importer is Europe Union (EU),followed by North America and Japan. United kingdom(UK) with 19% and Germany with 18% of the trade shares the market in EU and other importer of ornamental fish are France, Netherlands, Belgium, Spain and Italy. (Anon;2010) The ornamental sector is wide spread and global component of international trade,Fiseries,Aquaculture,and development.However,the scope of this sector and the impact on human and aquatic communities are often unknown and unappreciated (Anon;2008)
STATISTICAL OVERVIEW : IN INDIA
The export of Ornamental fishes from our country started during the year of 1969 with a few species of tropical freshwater fish with insignificant export earnings,which
increased to 10 corore rupees in 1994.It has also been noticed that Indian Ornamental fish are in greater demand in International market. (Ayyappan and Jena;2006)
According to Ziauddin et.al..,(2007) India has a great potential to increase the level of export to US $30 million every year.
As far as the ornamental fishes from India is concerned ,90% of total export are wild caught fishes of fresh water origin and it constitutes of Colisa fasciata, Tricogaster lalius, Dontiadeor spp, Tretradon spp, Chanda ranga, Esomus dandricus , etc. arising from north eastern region.The remaining 10% are either tank reared or breed and reared varities of
exotic species of freshwater or marine origine. (M.F.ScThesis: Sutradhar,D.,WBUAFS;2010) India export of Ornamental fish is dominated by wild caught fishes. At present ,India’s
overall trade in ornamental fish has crossed Rs.150 million. (Mahapatra;2015)The export is mainly carried out through the International Airports at Kolkata, Chennai, Mumbai,Thiruvantipuram and Cochin and about 50% of the total export (By value) takes
place from Kolkata. (Mahapatra;2015) In India about 80% of ornamental fishes are from freshwater and rest from brakish and
marine sector. (Mahapatra;2015)
STATISTICAL OVERVIEW : IN WESTBENGAL
The state of West-Bengal is situated between latitudes 21 ̊5 ́N and 24 ̊5 ́N and longitudes86 ̊E and 89 ̊E.WestBengal is having a vast area with very rich biodiversity of ornamental fishes. Kolkata is the major trade centre for ornamental fishes, followed by Mumbai, and Chennai. (Chand;2003;Mukherjee;2004)In WB ,a local entrepreneur on their own effort develops the production of Ornamental fishes with out the help of Govt. Agency. There is no technology ,infrastructural and institutional support from state for promoting their activities. As a result the industry is far from being organized.
Despite these bottlenecks, it is encouraging to note that a large no of entrepreneur in WB has started breeding, and rearing of ornamental fishes. In WB,719 units of ornamental fishes are there, where its’ breeding and culture are main curricula.(W.B.govt.annual report,2006-07)In WB, more than 2000 people involved in this trade including ornamental fish breeders, growers, seed and live food collectors, traders and exporters. About 150 families are involved in ornamental fish farming to maintain their livelihood. More than 500 families use it as their additional income generating business.(Ghosh et.al…2003)
CATEGORIZATION OF ORNAMENTAL FISHES BASED ON SPAWNING HABIT
Devraj K.V(1989) categories the Ornamental fishes into two broad categories based on their spawning habit. Such as-------1.Oviparous----Fishes that lays eggs.2.Ovoviviparous/Viviparous fishes(live bearers)----Fertilization is internal and the development takes place in the body of mother. After the development, young ones are released through the genital apertures of the female.
1.Oviparous
(A)Lay eggs and eggs are allowed to hatch un-attendent
(C)Lay eggs and guarded by parents but are direct contact with
the body
(B)Lay eggs and guarded by parents but are not direct contact
with the body
(A)Lay eggs and eggs are allowed to hatch un-attendent
Egg Scatterers Egg Hangers Egg Buryers Egg Stowers
Cynolebias adolfi Rhodeus sericeusAphyosemion australeCarassius auratus
(B)Lay eggs and guarded by parents but are not direct contact with the body
Egg Anchorers
Egg Splashers
Egg Hiders
Nest Builders
Egg Scoopers
Copeina guttata
Copeina arnoldi
Ttricogaster lalius
Pterophyllum scalare
Nnnacara anamala
(C)Lay eggs and guarded by parents but are direct contact with the body
Mouth Breeders
Geophagus balzani Pseudotrophus auratus Oreochromis mossambica
2.OVIVIPAROUS/VIVIPAROUS
Black Molly PlatySword Tail
Xiphophorus maculatus
Poecilia sphenops Xiphophorus hellerii
Gonopodium—Anal fin is modified to a trick road like structure which meant for inserting binto the genital aperature of the female during matting.Gravid Spot----Devoloping embroy can be seen on dark spot infornt of anal fin which is known as gravid spot.
SPECIES OVERVIEW
Tricogaster lalius, also known as Dwarf gourami.In WestBengal,this fish is locally
called”Kholse” or “Lal Kholse”.It is traditionally liked by the people for its good test and
fetches a market value of Rs-130 to 150/kg.Though it is categories under weed fish,male of
lalia has high foreign demand as aquirium fish due to lucrative colouration.It is naturally
collected and exported to the foreign countries i.e USA,Singapore,Japan,Srilanka,Bangladesh
,Malaysia,China. (Biswas and Lepcha,2004)
This species is listed on the IUCN red list as least concern(lc).The occurrence of this
species is very wide and there is no significant threat across its range.But due to high
exploitation of this species in the natural resources their habitat is lost for natural
propagation.So it is to be needed to think over artificial propagation to meet up such high
demand.The knowledge of reproductive cycle of the species will help in formulating
breeding and culture technology of the commercially important species for mass propagation
as well as conservation. (Gogoi et .al..2013)
Systematic position
KINGDOM: Animalia
PHYLLUM: Chordata
CLASS: Actinoptergii
ORDER: Perciformes
FAMILLY: Osphronemidae
GENUS: Trichogaster
SPECIES: Trichogaster lalius WWW.animalworld.com
Male and female species
CONTROVERSY over nomenclature
This species undergo a number of scientific name change.It was originally named
Trichopodus lalia in 1822 by Hamilton and Buchanan, from specimen of Gangetic
provinces of India.
Then a paper by Mayers (1929),resulted in a taxonomic mis intrepritation which was
recently discovered.But at the generic name Colisa was adopted for the western
species of gourami and generic name Trichogaster was adopted for eastern species.
Then the interpretation by Mayers,1923 came under review and taxonomical
structure revisited and restructure by Topfer and Schindler,2009.
Then they mentioned that species which had been placed under Colisa have now
been reverted back to Trichogaster, and that the species which had been placed under
Trichogaster have now been reverted back to Trichpodus.
MORPHOLOGICAL DESCRIPTION
The male dwarf gourami can reach about 3 inches(7.5cm) in length ,but there are report of same gourami upto 8.8 cm.The smaller female can reach upto 6 cm.
The body of dwarf gourami is strongly compressed and oval in shape and upward directed moth with normal lips and softer portion of dorsal sin is pointed.
Pelvic fin is present of single,elongated and filliform ray.
Width of anal fin is more than dorsal fin.Red spot present in the dorsal and anal fin.
This species is having translucent blue colour with vertical or diagonal stripes with an alternating red to dark orrange colour that entered upto caudal fins..
TalwarandJhingran,2001/Rahaman;2005
DISTRIBUTION AND HABITAT
Dwafr gourami is originally found in South Asia
from Pakisthan ,India, Bangladesh.At one time it believe to be found in Nepal and
Mayanmar, as well,but that is now thought to be mis
identification.They typically occure in the areas such as
Wetlands of Ganges River and those of
Yamuna ,Bhramhaputra and Brak River.
They are found together with other colisa
species.The fish is surface dweller and
insectivores.They are very hardy in nature and can
survive in foul water. Rahaman;2005
FOOD AND FEEDING
They are omnivorous in nature. It the wild they feed on small invertibrates,other
insect from top of water.
They also readily feed on algae and plant matter. In the aquarium they eat all kinds of
live fresh and flake floods such as blood worms and brine shrimp.
Feeding of live food is essential in conditioning fish for breeding. They easily suffer of
constipation, so it is important to feed with good foods in right way.
MASTERS THESIS,WBUAFS;Baksi.S.2016
REPRODUCTIVE BIOLOGY OF Trichogaster lalius
SEXTUAL DIMORPHISM
The sexes are separated.The male and female are distinguished only during the breeding season.Sexing of dwarf gourami was easily done bassed on some external sextual characters.
In case of male ,it was larger than female by body size.In the last tip of dorsal fin of male,it was pointed outside but, it was rounded in case of female. (Rainboth;koltelat,2001)
During breeding season, the male is attractive and more colorful than female. It has an almost translucent blue color with vertical diagonal stripes of alternating red and dark orange that extend into the fins. (Debkanta.et,al 2016)
Belly of the female during season is more bulginess than the male. (Khan;1982;Dehadraiet al.1973)
The bulginess of belly in female is more due to accommodation of mature eggs in the ovary. (Devkanta et;al,2016)
AGE AT FIRST MATURITY
The size at first reproduction has an important role in
understanding the life history of a species during its
evaluation and gives a rough estimation of ultimate
asymptotic size (Lᾳ) of the species (Biswas;2001)
The gouramies are anabantidae family.Three spot
gourami Trichogaster trichopterus will reach sextual
maturity at 7 cm and (12-14)weeks of age.(Mckinnon
and and Liley,1987)
Bhanu and Bhakta (1985) studied the maturity of banded
gourami,Colisa fasciatus.They found the first stages of
maturity of Colisa faciatus occures it (9-9.9)cm length at
an age of (10-12) months.
Matured Male with testis
Matured female with ovary
SPAWNING SEASON
According to Banu and Bhakta (1985),they observed that the spawning season of Colisa
faciatus to be form April to June in Bangladesh.
However ,Khan;(2004) has reported the breeding season of Colisa faciatus from Aprilto
july.
Devkanta et-al(2011) reported that the spawning of Trichogaster lalius is May –June.
Sanjeev et al (2016) reported that the breeding season of Trichogaster lalius is during
March to June.
Trichogaster lalius is a total spawner,its spawning is related with its total length ,body
weight,and gonad weight(Ringu et ,al;2016)
fecundity
Dsagupta (1988) and Musa and Bhuiya (2007) reported that the average prey spwaning
fecundity of Trichogaster Lalius was 1024 to 1351 in number for the fish average length
and weight of (43.6mm to 46.33mm) and weight 1.244gm to 1.808gm respectively.
On the other hand ,the relative fecundity of Trichogaster lalius was varrying from
747to 823 numbers of ova and it decrease with growth on the size of ova increase during
growth.(Phakon and Biswas;2002)
Sex- ratioFor avoiding infighting among male,most preferable
ratio for captive breeding is 1:1 (K.Fshim.et,al)
Abubakar(1972) reported that for successful breeding
of Trichogaster lalius most successful sex ratio should
be 1:1 where female get a chance to spawn totally.
Some Observation was seen in case of Colisa
faciatus,(Debtanu at al,2013) reported that sex ratio
should be maintained at 1:1 in case of healthy male
and female.
V.R Suresh at al,(2006) observed that in case Colisa
sota(Honey Gourami) a pair of sexually mature male
and female is most preferable for captive breeding
under laboratory.
CAPTIVE BREEDING OF Trichogaster lalius UNDER LABORATORY CONDITION
BROOD STOCK MAINTANANCE (V.R Suresh et al;2006 )
STEP-1
STEP-2
Matured male and female fishes are reared in aquarium(60×30×30)cm3
Before stocking they have to give a short treatment of bath treatment
with 2% potassium permanganate (KMnO4) solution for (3 to 5)min.
They are feed on zooplankton (copepode,cladocerans,ostracode,insect
larvae)and tubifex,worm twicw a daily (morning and evening) until
satiation.They are feed with commercially available feed(Tokiyo,japan)
STEP-3The accumulated fecal materials were siphoned out daily morning in
order to maintain healthy condition of fishes
STEP-4After 15 days of acclimatization the fishes were transferred for
breeding in the ratio of 1:1.
TEMPERATURE (27-30) c ̊DO (5.5-7.8)ppmPH (7-8.6)
HARDNESS (50-150)ppmAMMONIA (0.9-1.5)ppm
Physico-chemical parameters recommended ------------------(K.F.shima et; al..)
ACTUAL PHYSICO CHEMICAL PARAMETERS
PARAMETERS RANGE
TEMPERATURE (28-30 C ̊
PH 7.0-7.3
DISSOLVED OXYGEN (5-7) ppm
ALKALINITY (135-138) mg/lt
HARDNESS (461-471) mg/lt
DEPT. OF FRM ; Date- May and June,2015
NATURAL BREEDING OF Trichogaster lalius UNDER LABORATORY CONDITION
After someday from the introduction of both male and female(1:1)in the breeding
tank, male started bubble forming under the hidden place.
After introduction, male attracted to female, started chasing and during this
period male added few bubbles in his nest.
After sometimes male chased female aggressively, when the female tried to come
near to the nest.
After 24hrs.of chasing behavior when female showed response to male for
spawning, male leaves chasing and was sincerely engaged in making the nest for
spawning.
During this spawning time the male covered his body around the female such a
way that the belly portion of the female turned upwards.
After that male covered his body into a U-shape under Neath and squeezed
females abdomen to expel her eggs.
Eggs were stored in the cup for fraction of time and male also squeezed out
milt for fertilization.
No of eggs are released mainly depend upon pressing skill of male during
courtship
After every matting these released eggs are collected by male in his mouth for
few seconds and adds saliva on outer surface of eggs to make them sticky.
As soon as spawning is over male guarded his nest and do not allow female to
come near to the nest.
At that time, female has to be taken out from the tank ,if not it may eat up all
eggs, or male can damaged her seriously.
After removing female from the tank ,it should be treated with potassium
permanganate(KMno4)just to avoid infection.
CHARACTER OF EGGS
The fertilized eggs are small,spherical,transparent and off white but
unfertilized eggs are white, opaque and with a coating of fungus. The
unfertilized eggs are removed from the tank to avoid contamination rest of the
eggs. (K.Mitra at.al;2006)
EMBROYNIC DEVELOPMENT
Embryonic development is seen with help of phase contrast research
microscope. Eggs are collected from the tank with a pipette and place in a glass
slide. Under (26-28) ̊c temperature it takes 24-30hrs to become hatchlings.
(K.Mitra;et al.)
EMBROYNIC DEVELOPMENT
WBUAFSDEPT.OF FRM30TH MAY TO
30TH JULY,2016
13HR
19HR18HR
23HR 24HR 25HR 26HR
14HR
22HR21HR20HR
15HR 16HR 17HR
HATCHLINGS
The newly born larvae attached to the bubble nest for next three days, until the yolk sac was totally absorbed and then the hatchling black comma shaped larvae swim horizontally after 3th to 4th day of breeding. At that time male was removed from the tank. (K.Mitra et al;2006)
LARVAL REARING
UNDER LABORATORY REARING OUTDOOR POND REARING
K.Mitra et;al..(2006) K.F.Shim et;al2000
LARVAL REARING
UNDER LABORATORY RAEARING
From the 1st to 3rd day no feed was given as nourished from the yolk sac.
From the 4th to 10th day the feeding was done with laboratory prepared green water containing micro algae, mostly chlorella.
From 11th to 20th day the hatchlings were fed on laboratory prepared infosurians and boiled egg yolk.
From the 21th day onwards the feeding gradually switched to Copepodes,Cladocerans,Ostracodes,Insect larvae as young grew Tubifex
worms was included in daily diet.
SL NO FEMALE FISH WEIGHT BEFORE
SPAWNING(G)
FEMALE FISH WEIGHT AFTER
SPAWNING(G)
WEIGHT OF RIPE
EGG GSI(%)
1. 1.695 1.587 0.108 6.371
2. 1.300 1.240 0.060 4.615
3. 1.360 1.295 0.065 4.779
4. 1.501 1.404 0.092 6.129
5. 1.701 1.591 0.110 6.466
6. 1.356 1.292 0.064 4.719
7. 1.571 1.476 0.095 6.047
8. 1.301 1.239 0.062 4.765
9. 1.241 1.203 0.038 3.062
10. 1.380 1.312 0.068 4.929
STATISTICAL ANALYSIS OF DIFFERENT VARIABLES DURING BREEDING SEASON
weight variation in fish before and after spawning
1 2 3 4 5 6 7 8 9 100
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
FISH WEIGHT BEFORE SPAWNING(G) FISH WEIGHT AFTER SPAWNING(G) GONAD WEIGHT
Fish
wei
ght(g
m)
Gonad weight(gm)
relationship between fish weight and gsi(%)
1.695 1.3 1.36 1.501 1.701 1.356 1.571 1.301 1.241 1.382.9
3.4
3.9
4.4
4.9
5.4
5.9
6.4
6.9
GSI(%)
GSI(%)
Weight of the female before spawning(gm)
Gon
ado
som
atic
inde
x(%
)
STATISTICAL ANALYSIS OF DIFFERENT VARIABLES DURING BREEDING SEASON
SL NO GONAD WEIGH
T(G)
FECUNDITY(N
O)
RELATIVE
FECUNDITY(N
O)
EGG HATCHED(NO)
NO OF SURVIVE after 20 days
(NO)
HATCHING
RATE(%)
SURVIVABILIT
Y RATE(
%) after 20 days
1. 0.108 1350 796.460 893 410 66.14 45.912. 0.060 1040 800 609 220 58.55 36.123. 0.065 1120 823.529 627 245 55.98 39.074. 0.092 1345 822.784 844 385 68.34 45.625. 0.110 1345 790.711 742 338 55.16 45.556. 0.064 1100 811.209 737 310 67.00 42.067. 0.095 1265 805.219 837 370 66.16 44.208. 0.062 1060 814.757 666 270 62.83 40.549. 0.038 1000 805.801 660 260 66.00 39.39
10. 0.068 1156 837.681 699 285 60.46 40.77
1 2 3 4 5 6 7 8 9 10
13501040 1120
1345 13451100
12651060 1000
1156
893
609627
844 742
737
837
666 660699
FECUNDITYFECUNDITY(NO) EGG HATCHED(NO)
Fecundity(no)
1 2 3 4 5 6 7 8 9 100%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
EGG HATCHED(NO) FECUNDITY(NO)
Hatching rate(%)
SURVIVABILITY RATE(%) AFTER 20 DAYS
893 609 627 844 742 737 837 666 660 6990
5
10
15
20
25
30
35
40
45
50
survival rate %
No of Eggs Hatched
Surv
ivab
le ra
te (%
)
discussion from the ANALYSISIn the present study, it was found a direct relationship between fish weight and gonad weight of Trichogaster lalius. This indicates that the weight of the gonad was found to be increased with the increase in female’s weight.Similar result was observed by James and Sampath(2004).The number of eggs released was directly related to gonad weight and female body weight. This indicates that the number of eggs released by female was proportional to the gonad weight.In this study the absolute fecundity was (1000-1350) in number and mean relative fecundity was 810 eggs/g fish weight, which is similar to recommended fecundity. (Dsagupta (1988) and Musa and Bhuiya (2007) .But, the average hatching rate (%) in natural breeding was 66.66% and was found to be low. It was also found that the survivability rate of this species is between (36-46)%,which was very low as mortality occurred in 7 to 15 days.It can be attributed to local conditions of underground water, mainly Hardness (461-471) mg/lt which might have caused relatively low hatching rate and survival of larvae during the experiment.If we create actual simulated condition in the laboratory, such as water quality parameters, proper brood stock maintenance, larval feeding then this drawbacks can be over come and can fulfill the demand in market through artificial propagation.
LARVAL REARING
OUT DOOR POND REARING
After one week the gourami larvae have consumed their yolk sacs and are placed in small (12×6) m nursery ponds, free of adult fish. Each of this pond is fertilized with 15 to 20 kg of chicken manure two days before the larvae
are stocked and is covered with fine mesh net to prevent the entry of predacious insects and birds
About 20000 larvae are stocked in each nursery ponds and fed four to five boiled egg yolks per pond twice a day. After one week, 30gm of live Moina
are added along with the egg yolks. This is increased 60 gm as the larvae grow into fry stage.
Nursery pond management
Releasing of larvae
Boiled egg yolk for feeding
Application of chicken manure
Live moina
After 20 days in the nursery pond, fry are transferred to 36×8 m grow-out pond. These ponds are fertilized with 40 kg of chicken manure with an additional 20 kg of manure one week later. The fry continue to be with Miona for another
20 days and switched to a powder mixture of wheat flour and fish meal. Supplemental vitamins are added to the mixture. The fry are feed twice day in
the morning and late in the evening.
Fry are kept in the medium sized (36×8)m grow out pond until they reach 30 mm in total length, which normally takes one to two months. Then they are transfers to large pond(40×15)m ponds. Where they are the flour-fish meal mixture exclusively. The fingerlings are in this large pond for two to three
months at which they are about 40mm in total length.
grow-out pond management
Grow out pond rearing Grow out pond rearing
Grow out pond rearingGrow out pond rearing
HARVESTINGTank culture systems eliminate aquatic emerging plants problems which lessens the
degree of management problems. One week before harvest, fish are sampled and examined
for any ectoparasites or bacterial infections, the proper treatment is applied if necessary,
and resample prior to harvest to insure the fish are in good health. These procedures insure a
smooth harvest and minimizes mortalities.
Harvesting Gouramies on a commercial scale is done by seining. To reduce injury a seine
net made of nylon knotless Ace or Delta weave netting with a mesh size of 1/8 inch is used.
Seine nets should have a length 2.5 times the width of the pond being harvested, and have a
depth two times the depth of the pond. Seines used for harvesting ornamental fish should also
be equipped with twice as many floats and bottom lead weights as is normally
recommended.
When using a seine net for harvesting, particular attention should be given so that the fish
are not overcrowded when pulling in the seine into the pond bank at the end of the harvest.
This could lead to excessive injury to the fish or stress which can cause future mortalities.
Name of the student topic year guide
Md. Ismile Khan Studies on sexual dimorphism and gonadal development of an indigenous ornamental fish, Colisa fasciatus (Bloch and Schneider)
2004 Dr. S.Behera
Oldalin KhongngainBiology and feeding ecology of an ornamental fish Colisa fasciatus in a lentic water body Shanti Jheel
2004 Prof. S. K. Das
Sudeshna Kumari Patro
The effect of female hormone (17β estradiol) on the phenotypic, bioindices and gonadal changes of male dwarf gourmy, Colisa lalia 2009 Dr. S.
Behera
Anupa BiswasThe effect of male hormone (17α MT ) on the phenotypic, bioindices and gonadal changes of male dwarf gourmy, Colisa lalia
2009Dr. S.
Behera
Debkanta SutradarStudies on seual dimorphism and gonadal development of an indigenous Ornamental fish Trichogaster lalius (Hamilton)
2011 Dr. S.Behera
RESEARCH WORK RELATED TO THIS TOPIC IN DEPT OF FRM ; FFSc; WBUAFS..
PLAN OF WORKWith a view to above reason,Trichogaster lalius ,play a vital role among Indian fresh water ornamental fish trade.Therefore to understand the breeding behaviour of this species and to better characterize the embroynic development, since very few has been done on Trichogaster lalius embroylogy;present piece of work may be entitled as” Study of natural breeding and embroynic development of Trichogaster lalius (dwarf gourami) under laboratory condition” is carried out with this following objectives..
1.To study the morphological dimorphism of male and female Trichogaster lalius.
2.To study the breeding behaviour of Trichogaster lalius.
3.The relationship of body weight with respect to gonad weight,fecundity and hatching rate.
4.To describe the embroynic development stages of Trichogaster lalius after natural breeding in laboratory condition.
CONCLUSION
Trichogaster lalius can be easily matured and bred successfully under
captive conditions similar to that the Indian Major carp. Brood stock
management and hatcheries should be established for conservation, and
ranching be initiated for sustained natural recruitment of the species.
Establishment of proper sanctuaries in selected areas of rivers, floodplain
and reservoirs is recommended for conservation of this species.
So, due to high exploitation of this fish in the natural resources their habitat
is lost for natural propagation.So,it is to be needed to think over artificial
propagation to meet such demand.
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