Journal of

Environment & Research VINANIE PUBLISING

Induced ovulation and spawning of African catfish Clarias gariepinus (Bloch) using ovaprim

Kasi Marimuthu,1,* Nirmell Satthiyasilan,1 M. Aminur Rahman,2 A. Arshad,2 M. Gokul Raj,3 Jesu Arockiaraj4,*

1 Department of Biotechnology, Faculty of Applied Sciences, AIMST University 08100 Bedong, Kedah Darul Aman, Malaysia2 Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia3 Department of Civil Engineering, Sree Sastha Institute of Engineering and Technology Chembarambakkam, Chennai 600 123, Tamil Nadu, India4 Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India

ORIGINAL RESEARCH ARTICLE

ABSTRACT Experiments were conducted to study the effects of different doses of ovaprim in stimulating ovulation and

spawningresponseofAfricancatfish,Clarias gariepinus.Ninematuredfemaleand9malefishesweighingfrom1.46to2.80kgwererandomlyselectedforthreedifferentdosesofhormonalinjection.Bothmaleandfemalefishesfromallthethree replicate groups (3 females and 3 males per replicate) were administered a single dose of 0.4, 0.5 and 0.6 mL of ovaprim/kgbodyweight(BW),respectively.After12hofpost-injection,thefemaleswerestrippedindividuallyintodryand pre weighed plastic containers to record the stripped egg weight per female. The breeding performance was assessed onthebasisoftotaleggmassandstrippingresponse.Toassesstheeggqualityofhormoneinducedfishes,thefertilizationrate and hatching rates were examined among the three doses administered. Complete ovulation was observed in all the threedosesofhormonalinjection.Theresultsindicatedthatthetotalweightofstrippedeggsweresignificantlyhighest(P<0.05)attheindividualsreceived0.4mLovaprim/kgBWcomparedtothoseinjectedwithotherhigherdoses.Highestfertilization(97.88%)andhatching(93.66%)werealsorecorded in the individualsreceived0.4mLovaprim/kgBW.However,breedingperformanceandeggqualitywerenotstatisticallysignificantamongthethreehormonedosestestedin this study. Hence, it was evidenced that ovaprim, the synthetic gonadotropin-releasing hormone with a dopamine antagonist at a dose of 0.4 mL/kg BW could be used as an appropriate spawning dose for C. gariepinus.

KEYWORDSAfricancatfish;Clarias gariepinus;hormonaltreatment;inducedbreeding;seedproduction

1. INTRODUCTION

Africancatfish,Clarias gariepinus is one among the highly demanded freshwater food fish and cultivarspecies in Malaysia and other Asian and African countries due to its higher resistance to diseases, ability to tolerate a wide range of environmental parameters and high stocking culture conditions, relatively fast

growth rate and good quality meat (Hogendoorn, 1980;HuismanandRichter,1987;Haylor,1991;GoosandRichter,1996).Itisoneofthepopularnativefishspecies of African countries and has been introduced and commercially cultured in several countries in Europe (Netherlands, Germany and Belgium) andAsian countries (Indonesia, Thailand and Malaysia) and South America (Brazil). C. gariepinus inhabits

www.vinanie.com/jebrBiotechnology

Corresponding authors: K. Marimuthu (KM); J. Arockiaraj (JA)

Tel:+60-4-4298000(KM);+91-44-27452270(JA)Fax:+60-4-4298109(KM);+91-44-27453903(JA)E.mail:aquamuthu2k@yahoo.com(KM);jesuaraj@gmail.com(JA)

Recieved: 20-03-2015Revised:16-07-2015Accepted:29-07-2015Available online: 15-09-2015

Journal of Environment and Biotechnology Research, Vol. 1, No: 1, Pages 2-9, 2015

2

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015

a wide range of water bodies like swamps, lakes and rivers.Itisahardyfishandisabletothriveinharshenvironmental conditions such as muddy, turbid and oxygen depleted water bodies with the help of accessory air-breathing organ which allows them to breatheoxygen fromtheatmosphericair.Generally,C. gariepinus is omnivorous in nature and usually feeds on insects, plankton, snails and plant matters in the natural water bodies (Bruton, 1979; Uys,1989). However, this species is highly cannibalistic whensubstantialdifferencesoccurinsize(BarasandJobling, 2002). African catfish breeds naturally during therainy season in flooded rivers, inundated paddyfieldsandearthenponds.Theseedcollectionof thisspecies from the wild is unreliable, time consuming anduneconomicalforlarge-scalecultureofthisfish.To overcome these problems, induced spawning is thought to be the only alternative method for seed production and supply. Further, the rearing of the wild collected broodstock in captive conditions may not receive appropriate environmental cues for gonad maturation and spawning and it can cause reproductive development to be arrested in late vitellogenesis stage. Hence, matured females are induced to spawn by hormonal manipulation (Zohar and Mylonas, 2001). Over the last few decades, hormonal administration techniques have been used to induce finaloocytematurationandspawninginfisheswhichallowed the reproduction in controlled conditions (Marimuthu et al., 2007 & 2009; Marimuthuand Haniffa 2010). Moreover, induced breedingtechniques have significantly contributed a lot tothe expansionanddiversificationof the aquacultureindustry (Zohar and Mylonas, 2001). The injectionof different spawning agents in fish is adoptedfor successful ovulation and collection of eggs. Traditional methods of induced spawning in fishare based on the injection of GtH-II from differentsources, including extract of carp pituitary gland, partially purified fish GtH-II and mammalian GtH,especially human chorionic gonadotropin (HCG)(Lam, 1982; Donaldson and Hunter, 1983; Peter etal., 1988;Zairin et al., 1992;Goswami andSharma,1997). The GnRHa and domperidone are the mostpopular compounds for induction of ovulation and spermiationinvariousfishspecies.Theintroductionof GnRH analogues has been proven to be efficientin inducing maturation and spawning in many fishspecies (Tamaru et al., 1988; Thomas and Boyde,1988;Zohar,1988;Slateretal.,1995;Berlinskyetal.,1996;Larssonetal.,1997;Mylonasetal.,1997&1998).Similarly, an antidopaminergic drug, pimozide has

alsobeenfoundtobehighlyeffectiveforstimulatingthe spawning process of fishes mainly in cyprinidsandcatfishes(Billardetal.,1984;Tan-Fermin,1997).These hormones are used to stimulate the secretion of endogenous gonadotropin (Zohar, 1989 & 2001). Lin and Peter (1996) reported that among the several inducing agents used in fish breeding,salmon gonadotropin releasing hormone (sGnRH)or luteinising hormone releasing hormone (LHRH) analogues in combination with dopamine antagonists were identified as effective agent in fish breedingand seed production. Several practical problems have been reported using exogenous hormones and endogenous hormones, such as weighing of such low quantity, preparation of these analogues and storage of this hormone in prepared solutions. Due to these difficulties, fish breeders and farmers areunwilling to use these hormonal preparations under farm conditions. Commercially available synthetic ovulating agents in ready-made form which contained GnRHa and dopamine antagonist such as ovaprim,ovatide, ovopel, dagin and aquaspawn are becoming verypopularnowadaysandfoundtobeefficientandsuccessful spawning agents in different fish species(Nandeeshaetal.,1990;Peteretal.,1988;Brzuska,1998; Cheah and Lee, 2000; Das, 2004). Recently,successful spawning through a synthetic analogue of GnRHhasbeenreportedinseveralairbreathingfishspecies including Clarias batrachus(Basuetal.,2000;Sahoo et al., 2008), Heteropneustes fossilis (Alok et al.,1993and1994;Marimuthuetal.,2000),murrel(Haniffaetal.,2003&2004;Marimuthuetal.,2001a&2001b,Marimuthuetal.,2007&2009;MarimuthuandHaniffa2010).However,theinformationontheinduction of spawning and artificial reproductionusing synthetic hormones in C. gariepinus is limited. Therefore, the present study was conducted to investigate theefficacyofa syntheticGnRH,witha dopamine antagonist (ovaprim) for the induction of ovulation and spawning performance in C. gariepinus;also to determine the minimum effective dose ofovaprim for induced spawning and seed production of thecandidatefishspeciesunderacontrolledcondition.

2. MATERIALS AND METHODS

2.1. Broodstock collection, maintenance and selection

Broodfishes(livebodyweightrangedbetween1.5and3kg)wereobtainedfromalocalfishfarmatSungaiPetani, Kedah Darul Aman, Malaysia. The collected

3

fisheswere transported to the AquacultureResearchLaboratory, AIMST University, Kedah Darul Aman, Malaysia and maintained in circular cement tanks. They were regularly fed with a commercial pellet feed containing30%crudeproteinat5%oftheirestimatedbody weight for two weeks. Nine matured females and

9 males were randomly selected and divided into three treatment groups, each group comprised of three males andthreefemales.Thematuredmaleandfemalefisheswereidentifiedbasedontheirexternalmorphologicalfeatures. Matured male fish was identified by aprominent slightly pointed genital papilla, and mature

4

Figure 1.Identificationoffemale(leftside)andmalefish(rightside)

Figure 2.Intramuscularinjectionofhormoneovaprim

Figure 3. Collection of eggs Figure 4.Eggmassofcatfish

Figure 5. Macerate testis and collection of sperm Figure 6. Mixing sperm suspension and eggs for fertilization

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015

females by a swollen abdomen and a reddish round vent (Figure 1). In addition, maturity of the female was confirmedbygentlepressingontheventralsideofthefishforoozingeggs.Theeggswerecollectedbyhand-stripping,andimmersedinasolutionconsistsof70%aceticacidand30%absolutealcoholforclarificationofthe cytoplasm. After about three minutes, the position of the oocyte nuclei was determined under microscope. Migration of the nucleus from the center of eggs to the periphery region indicates the readiness of fishfor breeding and is the best moment for hormonal stimulation as observed in other fish species. Onlythose females showing the highest percentage of mature oocytes having germinal vesicle in the center or initial stage of migration were selected for the hormonal treatment (Billard et al., 1984).

2.2. Hormone administration, gamete collection, fertilization and hatching

The selected fishes were randomly assigned to threetreatment groups and were injected intramuscularlywith 0.4, 0.5 or 0.6 mL ovaprim/kg BW (Figure 2). For eachdose,threebreedingtrialsweremadetofindoutthespawningresponseof thefishand toobserve thevariationinincubationperiod,rateoffertilizationandpercentage of hatching. The hormone-administered males and females were released separately into the circular cement tanks. After 12 h, the females were stripped individually and eggs were collected into dry and pre-weighed plastic containers to record the weight of stripped eggs (Figures 3 and 4). The testes wereremovedfrommalefishes,incisedandsqueezedto get concentrated sperm (Figure 5). The sperms were diluted with 5 mL of physiological saline to prepare a sperm suspension. The eggs were thoroughly mixed with sperm suspension and left for 5 minutes (Figure 6). After 3-4 consecutive washing with water, they were transferred into glass aquaria (40 L) provided with continuous aeration. The breeding performance was assessed on the basis of total egg mass and stripping response. The water quality parameters recorded duringthestudywereasfollows:temperature,27.5-29.5 0C;dissolvedoxygen,5.4-6.0mg/LandpH7.8-8.5.Thepercentageoffertilizationandhatchingrateswere calculated as follows:

Fertilization (%) = number of fertilized eggs/totalnumber of eggs counted x 100 (1)

Hatching(%)=numberofeggshatched/totalnumberof eggs in a batch x 100 (2)

2.3. Data analysis

Thedatafortotaleggmass,fertilizationrate,incubationperiodandhatchingratewereanalyzedusingonewayanalysis of variance (ANOVA) followed by Duncan’s NewMultipleRangeTestsatthesignificantlevel,P=0.05. All the statistical analyses were performed using thecomputerizedstatisticalpackage,SPSS(ver.13.0).

3. RESULTS AND DISCUSSION

Complete ovulation and spermiation was observed in all the three hormone dosages tested in the study. No significantsizevariationsofthemaleandfemalefisheswere used for breeding among the three hormonal treatments. The results obtained from the induced spawning experiments are summarized in Table 1.The results indicated that the total weight of stripped eggswere significantly highest (P<0.05) in femalesreceived 0.4 mL hormonal dose than those females administeredwithhigherdoses. Significantlyhighestpercentages (P < 0.05) of fertilization rate (97.88%)and hatching rate (93.66%) were also recorded inthe females received 0.4 mL ovaprim than those receivedhigherdoses.However,bothfertilizationrateand hatching rates were not statistically significantamong the females received 0.5 and 0.6 mL/kg BW. Significantly longer(P<0.05) incubationperiodwasobserved in the individuals administered with 0.4 mL ovaprim than those administered with 0.5 and 0.6 mL hormone, the latter two doses did not statistically significantamongthem. In this study,a single intramuscular injectionof synthetic hormone, ovaprim resulted in successful spawning of C. gariepinus. Successful spawning using ovaprim and its analogues have also been reported in several fish species viz., carps (Nandeesha et al.,1990), stinging catfish H. fossilis (Vijayakumar etal., 1998), Ompok bimaculatus (Sridhar et al., 1998), murrel (Haniffa et al., 2003 and 2004; Francis etal., 2000), catfish Neosilurus ater (Cheah and Lee, 2000) and C. batrachus (Sahoo et al., 2008). Table 2 summarizes the results of induced spawning andsuccess rate of different fish species using ovaprim.It has been reported that the ability to induce oocyte maturation and ovulation depend on the dose, species and maturation stage of the oocytes (Donaldson and Hunter,1983;Yaron,1995;Peteretal.,1988). Inthepresentstudy,significantlyhighest(P<0.05) amount of egg mass was found in C. gariepinus wheninjectedwith0.4mL/kgBWofovaprim.Further,

5

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015

complete spawning was also observed in all the three doses tested. Complete spawning has also been reported using ovaprim in carps (Nandeesha et al., 1990), Puntius japonicus (Azad and Shimray, 1991),N. ater (Cheah and Lee, 2000), C. batrachus (Basu et al., 2000) and using ovatide in H. fossilis (Marimuthu et al., 2000) and Ompok pabo (Mukherjee andDas,2001).No significant differenceswere noticed in thehatching rates between the doses, 0.5 and 0.6 mL/kg BW tested. This observation suggests that inducing ovulation with ovaprim at higher doses did not have any adverse effect on egg viability. However, fishrespondsdifferently,wheninducedwithGnRHortheiranalogue(s) in terms of elevation in the gonadotropin levels(Peteretal.,1985;Bretonetal.,1990),steroid

levels (Weiletal., 1980;VanDerKraaketal., 1987),ovulation (Ramos, 1986; Peter et al., 1987; Fermin,1991),latencyperiod(DeLeeuwetal.,1985;Glubokovetal.,1986;KaulandRishi,1986)andspawning(Leeetal.,1986;Nandeeshaetal.,1990).Thevariationsinresponse canbeattributed to thefish species, aminoacidsequenceandpurityoftheGnRHanalogue(Peteretal.,1985&1987),doseof theGnRHandbasedonweak or strong dopaminergic inhibitory mechanism (Fermin, 1991). Ingeneral,theresponseoffishtoovaprimwasfound to be better, considering the spawning success, egg mass, percentages of fertilization and hatching.Further, the synthetic hormones like ovatide, ovapel and ovaprim are known to act at the pituitary level

6

Hormone dose mL/kg BW

Femalefishweight(kg)

Malefishweight(kg)

Total egg mass (g)

Fertilizationrate(%)

Incubation period (h)

Hatching (%)

0.4 1.98±0.73a 2.53 ± 0.46a 300 ± 90.0b 97.88±0.38a 27.6±1.2a 93.66 ± 2.96a

0.5 1.83 ± 0.15a 2.80 ± 0.10a 167±61.0a 92.77±5.59b 23.5 ± 1.0b 85.77±7.47b

0.6 1.46 ± 0.46a 2.46 ± 0.15a 163 ± 60.0a 95.66±3.67a 24.0 ± 0.9b 83.66 ± 2.51b

Table 1.InducedspawningofAfricancatfish, C. gariepinus using synthetic hormone ovaprim

Species Ovaprim (mL/kg bw)

Latency period (h)

Spawning success

Fertilizationrate(%)

Hatching rate (%)

References

Acanthopagrus latus 0.5 59 - 83 88 Leu and Chou (1996)

Aristichthys nobilis 0.6 8 Complete 98 100 Afzaletal.(2008)

Catla catla 0.4 9-10 Complete 80 90 Nandeesha et al. (1990)

Channa striatus 0.4 21 - 93 - Francis et al. (2000)

Channa punctatus 0.5 24 - - - Haniffaetal.(2003)

Cirrhinus mrigala 0.35 15 Complete 86 90 Nandeesha et al. (1990)

Clarias batrachus 2.0-2.5 16-17 Complete 60-65 - Mohapatra et al. (2000)

Clarias batrachus 2.0 16-18 Complete 80 60 Basu et al. (2000)

Clarias batrachus 1.0-1.5 14-17 Complete - - Sahoo et al. (2008)

Ctenopharyngodon idella 0.7 8 Complete 95 100 Nandeesha et al. (1990)

Heteropneustes fossilis 0.6 14-12 Complete - - Alok et al. (1993)

Heteropneustes fossilis 0.4 11-1 2 Complete 80-84 - Francis (1996)

Heteropneustes fossilis 0.5 10-24 - - 80 Vijayakumaretal.(1998)

Hypopthalmichthys molitrix 0.5 12 - - - Peter et al. (1988)

Hypopthalmichthys molitrix 0.7 15 Complete 53 - Nandeesha et al. (1990)

Labeo rohita 0.4 10-13 Complete 76-98 90-95 Nandeesha et al. (1990)

Neosilurus ater 0.5 17-23 Complete 90 79 Cheah and Lee (2000)

Ompok bimaculatus 0.5 5-6 - 75 60 Sridhar et al. (1998)

Puntius japonicus 0.4 8 Complete 90 59 AzadandShimray(1991)

Tor puttitora 0.2 24 - 70-80 60-65 Pandey et al. (1998)

Channa striatus 0.4 23 complete 99 92 Marimuthu et al. (2001b)

Meanvaluesintheeachcolumnwiththedifferentsuperscriptletteraresignificantlydifferent(P<0.05)

Table 2.Summaryofinducedbreedingindifferentfishspeciesusingovaprim

‘-’ not mentioned

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015

leadingtothesecretionofthefish’sownendogenousgonadotropins, while in the case of hypophysation technique and administration of HCG, exogenousgonadotropins are directly delivered into the body (Habibietal.,1989;Zairinetal.,1992;GoswamiandSharma,1997).Endogenousgonadotropinsappear tosignificantlyenhancethesecretionoftherighttypeofsteroids in appropriate quantities, enabling complete maturation of ova.

4. CONCLUSIONS

From the present findings, it is evidenced that thesynthetic gonadotropin-releasing hormone with a dopamine antagonist at the low dose of 0.4 mL/kg BW could be used as an appropriate spawning agent for successful breeding and seed production of C. gariepinus. The results emerged from the present study would immensely be helpful for quality seed production in African catfish. Further studies arerequired to examine the development and growth performances of larvae and fry produced by the induced breeding techniques. REFERENCES

Afzal,M.,Rab,A.,Akhtar,N.,Khan,M.F.,Khan,S.U.andQayyum,M. (2008) Induced spawning of bighead carp, Aristichthys nobilis (Richardson), by using different hormones/hormonalanalogues.PakistanJournalofZoology,40,283-287.

Alok,D., Krishnan, T., Salunke,D.,Gupta,H., Talwar,G.P. andGarg,L.C.(1994)Precociousovarianrecrudescenceandinducedoff season spawningof catfishHeteropneustes fossilis (Bloch) by D-Lys6 salmon gonadotropin releasing hormone analog (SGnRHa).JournalofFishBiology,45,909-915.

Alok,D.,Krishnan,T.,Talwar,G.P.andGarg,L.C.(1993)InducedspawningofcatfishHeteropneustes fossilis (Bloch) using D-Lys6 salmon gonadotropin releasing hormone analog. Aquaculture, 115,159-167.

Azad, I.S. and Shimray, D.K. (1991) First success in inducedbreeding of Indian and exotic carps in Manipur using ovaprim-C. Fishing Chimes, 10, 28-29.

Baras, E. and Jobling, M. (2002) Dynamics of intracohort cannibalism in cultured fish. Aquaculture Research, 33, 461-479.

Basu, D., Rana, G.C., Mondal, B.K., Sengupta, K.K. and Dhar,P.K.(2000)Studiesonthecomparativeefficiencyofovaprim,HCGandpiscinepituitaryglandininducedbreedingofClarias batrachus (Linn). Fishing Chimes, 19, 103-104.

Berlinsky, D.L., King, V.W., Smith, T.I.J., Hamilton, R.D. and Holloway,S.C.R.(1996)InducedovulationofsouthernflounderParalichthys lethostigma using gonadotropin releasing hormone analogue implants. Journal of World Aquaculture Society,27,43-52.

Billard, R., Reinaud, P., Hollebecq, M.G. and Breton, B. (1984)Advancement and synchronization of spawning in Salmo gairdneri and Salmo trutta following administration of LHRHa-combinedornotwithpimozide.Aquaculture,43,57-66.

Breton,B.,Weil,C.,Sambroni,E. andZohar,Y. (1990)EffectofacuteversussustainedadministrationofGnRHaonGtHreleaseand ovulation in the rainbow trout, Oncorhynchus mykiss. Aquaculture,91,371–383.

Bruton,M.N. (1979) The food and feeding behaviour ofClarias gariepinus(Pisces;Clariidae)inLakeSibaya,SouthAfrica,withemphasis on its role as a predator of cichlids. Transactions of the ZoologicalSocietyofLondon,35,47-114.

Brzuska,E.(1998)OvopelasovulationstimulatorinAfricancatfish(Clarias gariepinusBurchell1822)females.ScientificPapersofPolish Academy of Science. Selected Problems, 5, 94-95.

Cheah, M.S.H. and Lee, C.L. (2000) Induced ovulation of the Australian eel tailed catfish Neosilurus ater (Perugia) with ovaprim.AsianFisheriesScience,13,87-96.

Das, S.K. (2004) Evaluation of a new spawning agent, ovopel in inducedbreedingof Indiancarps.AsianFisheriesScience, 17,313-322.

DeLeeuw,R.,Goose,H.J.T.,Richter,C.J.J.andEding,E.H.(1985)Pimozide- LHRH-induced breeding of the African catfish,Clarias gariepinus (Burchell). Aquaculture, 44, 295-302.

Donaldson,E.M.andHunterG.A.(1983)Inducedfinalmaturation,ovulation and spermiation in cultured fish. In: Hoar, W.S.,Randall, D.J. and Donaldson, E.M. (Eds.), Fish Physiology. Vol. IX, Part B: Reproduction. Academic Press: Orlando, FL, pp. 351-403.

Fermin, C.A. (1991) LHRHa and domperiodone-induced oocyte maturation and ovulation in bighead carp, Aristichthys nobilis (Richardson).Aquaculture,93,87-94.

Francis,T.(1996)Studiesontheeffectofpituitaryhormonesandfeeds on the reproduction of Heteropneustes fossilis (Bloch). Ph.D Thesis, Tamilnadu Veterinary and Animal Sciences University, Madras, India.

Francis, T., Ramanathan, N., Athithan, S. and Cheryl, H.F. (2000) Induced breeding of murrel, Channa striatus using various inducing agents. Fishing Chimes, 19, 119-121.

Glubokov, A.I.,Motloch,N.N. and Sedova,M.A. (1991) Effect ofa synthetic LHRH analogue and dopamine antagonists on the maturationofbream,AbramisbramaL.Aquaculture,95,373-377.

Goos, H.J.T. and Richter, C.J.J. (1996) Internal and externalfactorscontrollingreproductionintheAfricancatfish,Clarias gariepinus. In: Legendre, M., Proteau, J. P. (Eds.), The Biology andCultureofCatfishes.AquaticLivingResources,9,45-58.

Goswami,U.G.andSharma,N.N.(1997)Pituitarydoseoptimizationfor induced ovulation, in vitro fertilization and production ofnormal fry of Clarias batrachus (Linn). Asian Fisheries Science, 10,163-167.

Habibi, H.R., Marchant, T.A., Nahorniak, C.S., Van Deroo, H., Peter, R.E., Rivier, J.E. and Vale, W.W. (1989) Functional relationship between receptor binding and biological activity for analogs of mammalian and salmon gonadotropin-releasing hormones in the pituitary of goldfish (Carassius auratus). Biology of Reproduction, 40, 1152-1161.

Haniffa,M.A.,Marimuthu,K.,Nagarajan,M.,Arockiaraj, J. andKumar, D. (2004) Breeding behaviour and parental care of the induced bred spotted murrel Channa punctatus under captivity. CurrentScience,86,1375-1376.

Haniffa,M.A., Nagarajan,M.,Marimuthu, K. and Arockiaraj, J.(2003) Embryonic and larval development of spotted murrel Channa punctatus (Bloch). Indian Journal of Fisheries, 50, 355-362.

Haylor, G.S. (1991). Controlled hatchery production of Clarias gariepinus (Burchell 1882): growth and survival of fry at high stocking density. Aquaculture and Fisheries Management, 22, 405-422.

7

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015

Hogendoorn, H. (1980). Controlled propagation of the African catfish,Clarias lazera (CandV), 111. Feeding and growth of fry. Aquaculture, 21, 233-241.

Huisman, E.A. and Richter, C.J.J. (1987) Reproduction, growth,healthcontrolandaquaculturepotentialof theAfricancatfishClarias gariepinus (Burchell, 1822). Aquaculture, 63, 1-14.

Kaul, M. and Rishi, K.K. (1986) Induced spawning of the Indian majorcarp,Cirrhina mrigala (Ham.), with LH-RH analogue or pimozide.Aquaculture,54,45-48.

Lam, T.J. (1982) Application of endocrinology to fish culture.Canadian Journal of Fisheries and Aquatic Sciences, 39, 111-137.

Larsson,D.G.J.,Mylonas, C.C., Zohar, Y. andCrim, L.W. (1997)Gonadotropinreleasinghormoneanalogue(GnRH-A) inducesmultiple ovulations of high-quality eggs in a cold-water, batch-spawning teleost, the yellowtail flounder (Pleuronectes ferrugineus). Canadian Journal of Fisheries and Aquatic Sciences,54,1957-1964.

Lee, C.S., Tamaru, C.S., Kelley, C.D. and Banno, J.E. (1986). Induced spawning of milkfish, Chanos chanos by a single injectionofLHRHanalogue.Aquaculture,58,87-98.

Leu, M.Y. and Chou, Y.H. (1996) Induced spawning and larvalrearing of captive yellowfish porgy, Acanthopagrus latus (Houttunyn). Aquaculture, 143, 155-166.

Lin,H.R.andPeter,R.E.(1996)Hormonesandspawninginfish.Asian Fisheries Science, 9, 21-33.

Marimuthu, K. and Haniffa, M.A. (2010) Induced spawning ofnative threatened spotted snakehead fish, Channa punctatus withOvaprim.AsianFisheriesScience,23,60-70.

Marimuthu,K.,Haniffa,M.A.andRahman,M.A.(2009)Spawningperformance of native threatened spotted snakehead fish,Channa punctatus induced with ovatide. Acta Ichthyologica Piscatoria,39,1–5.

Marimuthu,K.,Haniffa,M.A.,Arockiaraj,A.J.andMuruganandam,M. (2001a) Spawning and parental behaviour in the induced bred murrels. Indian Journal of Fisheries, 48, 409-411.

Marimuthu,K.,Haniffa,M.A.,Muruganandam,M.andArockiarajA.J.(2001b)Lowcostmurrelseedproductiontechniqueforfishfarmers. Naga (ICLARM), 24, 21-22.

Marimuthu, K., Kumar D. and Haniffa. M. A. (2007) Inducedspawning and seed production of striped snakehead Channa striatus using ovatide. Journal of Applied Aquaculture, 19, 95-103.

Marimuthu, K., Muruganandam, M. and Haniffa, M.A. (2000)InducedspawningoftheIndiancatfishHeteropneustes fossilis (Singhi) using a synthetic hormone, ovatide. Fishing Chimes, 19, 105-106.

Mohapatra,B.K.,Sengupta,K.K.,De,U.K.,Rana,G.C.Datta,A.,Basu, A. and Saha, S. (2000) Controlled breeding and larval rearing of Clarias batrachus (Linn) for mass scale propagation. FishingChimes,19,97-102.

Mukherjee,M.andDas,S.(2001)ArtificialpropagationofasiluridfishpabdaOmpok pabo (Hamilton).FishingChimes,21,75-79.

Mylonas,C.C.,Gissis,A.,Magnus,Y.andZohar,Y.(1997)Hormonalchanges in male white bass (Morone chrysops) and evaluation ofmiltqualityafter treatmentwithasustained-releaseGnRHdelivery system. Aquaculture, 153, 301-313.

Mylonas, C.C., Woods, L.C., Thomas, P. and Zohar, Y. (1998)Endocrineprofilesoffemalestripedbass(Morone saxatilis) in captivity,duringpostvitellogenesisandinductionoffinaloocytematuration via controlled-release GnRH-delivery systems.GeneralandComparativeEndocrinology,110,276-–289.

Nandeesha,M.C.,Rao,K.G.,Jayanna,R.,Parker,N.C.,Varghese,T.J. and Keshavanath, P. (1990) Induced spawning of Indian majorcarpsthroughsingleapplicationofovaprim.In:Hirano,R., Hanyu, M. (Eds.), The Second Asian Fisheries Forum, Asian Fisheries Society, Manila, Philippines, pp. 581-595.

Pandey, A.K., Patiyal, R.S., Upadhyay, J.C., Tyagi, M. and Mahanta, P.C. (1998) Induced spawning of the endangered golden mahseer, Tor putitora,withovaprimatthestatefishfarmnearDehradun.IndianJournalofFisheries,45,457-459.

Peter, R.E., Lin, H.R. and Van Der Kraak G. (1988) Inducedovulationandspawning incultured freshwaterfish inChina:advanced in application of GnRH analogue and dopamineantagonists.Aquaculture,74,1-10.

Peter, R.E., Nahorniak, C.S., Sokolowska, M., Chang, J.P., Rivier, J.E.,Vale,W.W.,King,J.A.andMillar,R.P.(1985)Structure–activity relationship of mammalian, chicken and salmon gonadotropin releasing hormone in vivo in goldfish. Generaland Comparative Endocrinology, 58, 231-242.

Peter, R.E., Sokolowska, M., Nahorniak, C.S., Rivier, J.E. and Vale,W.W.(1987)Comparisonof[D-Arg6Trp7Leu8Pro9]netsGnRH-A,and[DAla6,Pro9net.]LHRH-A,incombinationwithpimozideinstimulatinggonadotropinreleaseandovulationinthegoldfish,Carassiusauratus.Canadian JournalofZoology,65,987-991.

Ramos,J.(1986)Luteinizinghormonereleasinghormoneanalogue(LH-RHa) induced precocious ovulation in common sole (Solea solea L.). Aquaculture, 54, 85-190.

Sahoo,S.K.,Giri,S.S.andChandraS.(2008)InducedspawningofClarias batrachus (Linn.):Effectofovaprimdosesandlatencyperiods on the weight of stripped eggs and ovary. Asian Fisheries Science, 21, 333-338.

Slater,C.H.,Schreck,C.B.andAmend,D.F.(1995)GnRHainjectionaccelerates final maturation and ovulation/spermiation ofsockeye salmon (Oncorhynchus nekra) in both fresh and salt water.Aquaculture,130,279-285.

Sridhar, S., Vijayakumar, C. and Haniffa, M.A. (1998) Inducedspawning and establishment of a captive population for an endangeredfish,Ompok bimaculatus in India. Current Science, 75,1066-1068.

Tamaru,C.S.,Lee,C.S.,Kelley,C.D.,Banno,J.E.,Ha,P.Y.,Aida,K.andHanyu,I.(1988)Characterizingthestageofmaturitymostreceptive to an acute LHRH-analogue therapy for inducing milk fish(Chanos chanos)tospawn.Aquaculture,74,147-163.

Tan-Fermin,J.D.,Pagador,R.R.andChavez,R.C.(1997)LHRHaand pimozide- induced spawning of Asian catfish Clarias macrocephalus (Gunther)atdifferent timesduringanannualreproductive cycle. Aquaculture, 148, 323-331.

Thomas, P. and Boyde, M. (1988) Induced spawning of spotted sea trout, red drum and orangemouth corvine (family: Scianidae) with luteinizinghormone-releasinghormoneanalog injection.ContributionsinMarineScience,30,43-47.

Uys, W. (1989) Aspects of the nutritional physiology and dietary requircmcntsof juvenileandadult sharptoothcatfish,Clurias gariepinus (Pisces: Clariidae). PhD Thesis, Rhodes University, South Africa.

Van Der Kraak, G., Donaldson, E.M., Dye, H.M., Hunter, G.A.,Rivier, J.E. andVale,W.W. (1987)Effectsofmammalianandsalmon gonadotropin releasing hormone and analogues on plasma gonadotropin levels and ovulation in coho salmon Oncorhynchus kisutch. Canadian Journal of Fisheries and Aquatic Sciences, 44, 1930-1935.

8

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015

Vijayakumar, C., Sridhar, S. and Haniffa,M.A. (1998) Low costbreedingandhatchingtechniquesofthecatfish(Heteropneustes fossilis)forsmall-scalefarmers.Naga(ICLARM)21,15-17.

Weil, C., Fostier, A., Horvath, L., Marlot, S. and Berscenyi, M. (1980)Profilesofplasmagonadotropinand17beta-estradiolinthe common carp, Cyprinus carpio L., as related to spawning induced by hypophysation or LH-RH treatment. Reproduction, Nutrition, and Development, 20, 1041-1050.

Yaron,Z.(1995).Endocrinecontrolofgametogenesisandspawninginductionincarp.Aquaculture,129,49-73.

Zairin, M., Furukawa, K. and Aida, K. (1992) Induction of ovulation by HCG injection in the tropical walking catfish Clarias batrachus reared under 23–25 0C. Bulletin of the Japanese SocietyofScientificFisheries,59,1681-1685.

Zohar, Y. (1988) Gonadotropin releasing hormone in spawninginduction in teleosts: basic and applied considerations. In: Zohar,Y.andBreton,B.(Eds.),Reproductioninfish:basicandapplied aspects in endocrinology and genetics, INRA Press, Paris,pp.47-62.

Zohar, Y. (1989) Fish reproduction, its physiology and artificialmanipulation. In: Shilo, M.C. and Sargi, S.H. (Eds.), Fish culture in warm water systems, problems and trends, CRC Press, pp. 65-119.

Zohar, Y. and Mylonas, C.C. (2001) Endocrine manipulation ofspawning induction in cultured fish from hormone to gene.Aquaculture,197,99-139.

9

K. Marimuthu, Journal of Environment and Biotechnology Research, Vol. 1, No.1, Pages 2-9, 2015