Tap chi Khoa hoc - Cong nghe Thuy sdn So 2/2014
KET QUA NGHIEN CCfU DAO TAO SAU DAI HOC
ANH HlTOfNG CUA MAT DO UONG LEN SINH TRlTOfNG VA TY LE SONG CUA AU TRUNG HAU TAM BQl THAI BINH DU'OfNG
{Crassostrea gigas Thunherg, 1793)
EFFECT OF REARING DENSITY ON GROWTH AND SURVIVAL RATE OF TRIPLOID PACIFIC OYSTER LARVAE (Crassostrea gigas Thunberg, 1793>
Bdo Trdn Tan Ddo', Tp Nggc Himg', Trifffng Thj Bich H6n^
Ngay nhan bai: 19/8/2013, Ngay phan bi?n thong qua. 05/9/2013, Ngay duy?i dang: 02/6/2014 T O M TAT
Trong nghien cieu nay, 4 mat do lecmg (1, 3, 5 va 7 con/ml) duac thii nghidm nhdm tim ra mat dg thich hcrp cho ucmg du triing hau tam bQi Thai Binh Duong giai dogn du triing chir Veliger den Spat (15 ngdy tuoi). Kit qud nghien cicu cho thdy. toe dp sinh Irudng tuyel doi vd toe do sinh tnrdng tirong doi ciia hdu dgt cao nhdt & mdt do ucmg 1 vd 3 con/ml, dip theo la mat dp 5 con/ml vd thap nhdt a mdt dp 7 con/ml (p< 0,05). Tyle song ciia du triing hdu dat cao nhat a mat do ucmg 3 con/ml (p <0.05). Khong co su khac btet thong ke ve ty le sdng cua du trung hdu giira cdc mat do mmg 5 con/ml so vai cdc mat dp uong 1 vd 3 con/ml (p > 0,05). Tic nghien ciru ndy co the nhdn thay, mat do thich hap cho ucmg du trimg hdu tam bpi Thdi Binh Ducmg Id 3 con/ml nhdm dam bdo toe do sinh trudng, ty 14 song cung nhu tdn diing lot the tich be uang.
Tic khoa • au triing, hdu Thai Binh Duang. mat dp, tam bpi, toe do sinh tru&ng, ty l^ song ABSTRACT
In this study, four densities 1. 3. 5 and 7 ind /ml were experimented in order to identify a suitable density for rearing triploid Pacific oyster fi-om the stages of Veliger to Spat (J 5 days). Results showed that the highest absolute growth rate and relative growth rate of the oyster larvae gained at the densities of 1 and 3 ind./ml, followed by the density of 5 ind./ml and lowest al the density of 7 ind/ml (p < 0.05). The highest survival rate of the oyster larvae was at the density of 3 indJml (p < 0 05) However, there was no sinificant difference about survival rate between the density of 5 ind./ml and those oj the densities 1 and 7 ind./ml (p> 0 05) From the results of this study, it can be suggested that the appropnate density for rearing the triploid Pacific oyster larvae was 3 ind./ml in order to optimize the growth, survival rate and tank rearing squares.
Keywords' density, growth rale, larvae. Pacific oyster, survival rate, triploid
L D A T V A N D t thay t h l , gidu vitamin vd khodng chat [12], [14).
Hdu Thai Binh Duang la loai dfing vat than Hdu da vd dang duac su dyng nhu id mfit logi thyc mlm thuoc io'p hai manh vo (Bivalvia) co gia trj pham bo sung dinh duang cin thiet, giup phdt trien kinh t l cao, thjt tham ngon vd dugc nhieu nguo'i chieu cao va tang cuang sinh luc cho nam gidi,.,.
ua chupng. Hdu Thai Binh Duang phan bo chfl yeu Ngoai ra, nufii hdu con co y nghTa quan frpng trong o- vung bien Thdi Binh Duang. Tuy nhifin, chung id vipc giai quylt 6 nhiem moi tnrang nuac nhfi d$c lodi rpng nhifit (0 - 36°C) va rfing muli {5 - 40%o) [7]. tinh dn Ipc cac chit huu ca cfla lodi dfing v|t than Do dfi, chflng dang dup'c di nhap va nufii 6- nhieu mlm nay [3].
quIc gia tren the giai trong dfi co Vifit Nam. Thjt hdu Tuy nhien, hdu lu&ng bfii thu&ng gay sau khi c6 gia trj dinh duo'ng cao vfi'i protein 45 - 75%, lipid sinh san Idm dnh huang rit l&n den chit lugng thjt, ty 7-11 %, gidu axit beo khong no vd axit amin khong lfi thjt fren vfi frilp, t i c dfi smh tnjang cham, tJ Ip song
' Ddo Trin Tan Ddo: Vi#n Nghign cu-u Nu6i trfing thiJy sSn 111
'Tg Ngpc Hung; Cao hpc Nu6l tring thuy sSn 2011 - Tru'&ng Ogi hpc Nha Trang ' ThS. Tnrong Thj Bich H6ng: Vi§n Nuoi trfing Ihuy san - Truing Dai hpc Nha Trang
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Tgp chi Khoa hoc - Cong nghe Thuy sdn So 2/2014
thip. D I khde phgc tat ca nhifng nhuac dilm tren, ritnhieu nhd khoa hpc trdn t h l gioi da nghien cuu va tgo ra dfing hau tam tjfii nhdm ndng cao ty le song, toe dfi smh truo'ng, ty le thit fren vfi.... [8]. Cdc phuang phap tgo dong tam bpi pho biln Id su dgng cdc tdc nhdn hfia hpc, vdt iy va sau do nhdn gilng chpn ipc [4], [11].
Q Viet Nam, ngay tfl" khi nhgp ve nuoi thfl" nghidm, hau TTial Binh Du^7r>g da nhanh chdng thich Cmg vol
^ l u kign nufii fi* cac viing nutrc Ipr mgn, ddc biet Id khu vuc mien Bac va Trung nuoc ta [1], [2].
Do hau Thdi Binh Duang khfing phdi Id lodi bdn
^ a nen vi#c nuoi thuong pham hodn todn phy thupc vao rtguln giong nhan tgo [4]. Chinh vi vdy, vipc nghien curu hoan thien quy frinh san xuat vd uong giong giu- vai tro h i t sue quan trpng gfip phin phdt trien nghe nuoi hdu o nuo'c ta [1]. K i t qud uong gifing hau phu thupc vdo rat nhieu yeu t l nhu thiJc dn, nhigt do, dp mgn, mgt dp uang,... Trong do. mat dp uang la mgt frong nhi/ng y l u to quan trpng anh huo'ng lan den sinh tnro'ng, phdt triln vd higu qud kinh ^ ky thugt cua nghi uang nufii hdu [2], [ 5], [6], [15], Vific gia tang mgt do uang giup tgn dgng tot dien tich nufii, gia tang higu qua kinh t l , tuy nhidn. no lai di kem vdi nhilu nji TO nhu Idm giam t i c dfi sinh truang, ty ie song, khd ndng khdng bgnh, dac bifit trong dieu kien uang nuoi vfii mat dfi cao [9], [10]. Tfly theo giai doan phdt trien md hdu thufinng dugrc uang a cac mdt dp khde nhau [10], [16]. Nghien cuu dup'c thuc hien nhim xde ^nh mat dfi uang phfl hp'p gop phan ndng eao t i c dp sinh tnrdng, ty 10 song va higu qua uong au trimg hau Thai Binh Duong fi' nucrc ta.
II. VAT U£U VA PHl/ONG PHAP NGHIEN CLFU 1. Vgt li^u va phipo^g phap bo tri thi nghidm
Nghifin cflu duoc thi/c hien tai Phdng Sinh hpc Thyc nghipm - Vien Nghien cuu Nufii fring ThCly san III tir 15/4 - 05/05/2012 frdn d l i tup'ng hau tam bfii Thdi Binh Duong {Crassostrea gigas Thunberg. 1793).
Nguin hdu frif nghi#m: Au trung hau dup'c smh sdn tir nguin hdu Thai Binh Duong dup'c nufii vd tgi dam Nha Phu. Nha Trang, Khdnh Hoa. Au trung hdu tam bpi duprc tao ra bang phuang phdp dflng hfia chit CB {Cytochalasin Binduced • C^H3,N05).
Nguyen ly cua phuang phdp ndy Id su dgng hoa chit CB (0,5 ppm, 15 phut) tdc dfing vdo glal dogn gidm phdn I hodc 11 nhdm ngan chdn sy hinh thdnh cdc CVC eau d i giu Igi hai bfi nhilm s i c t h l (2n) fi' trCrng vd khi k i t hp'p v6i bfi nhilm sac t h l dan bfii (In) cfla tinh trung se tgo thanh cd t h l co bfi nhilm sac fril tam bpi (3n) [17]. Au taing hau sau khi nfr
18 - 24 tiing tuong iing vfi'i giai dogn "chu D" duac bo fri nglu nhien vdo cdc nghifim theo cdc mdt dp thi nghidm. Tnj'fi'c khi thd vdo b l uang, l u trflng dup'c djnh lup'ng theo phuang phdp t h l tich.
Mat dp uang. Nghien cfl'u dnh huang cua mdt dfi uong len sinh truo'ng vd ty lg song cfla l u trung hdu tam bfii duae tiln hdnh 6 4 nghifim thiic 1, 3, 5 vd 7 con/mi. Thfi'i gian thi nghifim Id giai dogn l u trflng chO D (Veliger) den giai dogn l u trflng Spat (15 ngdy tuli). T i t cd cdc nghifim thi>c thi nghiem dup'c thue hien vol 3 lan lgp cflng thdi diem.
Dung cg thi nghigm: Au tnJng hdu tam bfii Thdi Binh Duangdup'c uong trong xfi nhya hinhtr6n(10L) dup'c cap nude vfi'i t h l tich 8 L/x6. Nuac bien su- dgng duprc Ipc sgch vol cde thong s l mfii tryfi'ng duac duy tri trong pham vi dp mdn 25 - 30%a;
pH 7,5 - 8,2; nhifit dfi 27 - 29°C va sgc khi 24/24h ddm bao oxy hoa tan trdn 6 mg/L. Toan bp hfi thong b l uong duoe ddt trong nhd co mdi die nhdm on dinh cdc yeu to moi trirang.
ThiJc an va che dp cho an: Thfl'c an cung c l p cho au trflng hau trong qua frinh uang la hon hap tdo dan bdo duac nufii sinh khoi Nannochloropsis oculata, Isochrysis galbana vd tao biln thu ngoai ty nhien. Cho an ngay 2 lan, buoi sdng 7 - 8 gicr va chieu 14 -16 gid. Luang tao cung cap vdo b l uang dup'c duy tri trong khoang 20 - 30 tripu te bdo/ml.
Qudn ly cdc y l u t l mfil tnrd'ng: Cac yeu to moi trudng nhu nhiet dp nudc, oxy hoa tan (do 1 ngdy/lan), pH, ham lup'ng NH^ vd H^S (do 10 ngdy/lan) dup'c kilm fra djnh kj/ bing cdc dyng cg (nhiet k l , test oxy, pH, NHj vd H^S) vd duy fri trong pham vi thich hp'p vdi sy sinh tnfdng vd phdt tnln cfla hdu. Hang ngdy. vd sinh, logi bo chat thai vd hdu chit nhdm ngdn ngfl'a tdc nhdn gdy bfinh.
2. Phirong phap thu thap vd xir ly so lieu Toe dfi sinh trudng tuydt doi vd tuong dol cfla hdu duyc xdc dmh djnh k.^ (5 ngdy/lln) bang cdch do 30 l u trung trong moi nghipm thuc dudi kinh hiln vi (Optika, Italia) vdi vdt kinh 40X cfi gdn thudc do kich thudc {dfi chlnh xdc 0,1 pm). Ty lg song cua hdu duac xdc dmh s l luprng hau cdn song tgi thdi diem ket thflc thi nghifim (15 ngdy tuli, hfong i>ng vdi l u trflng Spat).
Toe dfi smh trudng tuyfit doi AGR (pm/con/
ngdy) vd RGR tuang d l i (%):
AGR = | | f ^ (pm/con/ngdy) RGR = ^ ^ ^ x 100 (%) Trong 36: L l , L2. Chilu cao cua hdu d thdi dilmT1,T2(Mm);
T l , T2: Thdi dilm do kfch thudc hdu l l n tnrdc vd sau (ngdy).
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Tap chi Khoa hoc - Cong nghe Thdy sdn So 2/2014
Ty 10 song {%) = { S l au trung hau d giai dognmdi/sl l u trflng hau ban dau) x 100
Cdc so iifiu dugc xfl' ly bang phin mem SPSS 16.0. Su- dyng phuang phap phdn tich phuang sai mfit yeu to (oneway - ANOVA) vd phep kilm djnh Duncan d l so sdnh sy khac bifit cfi y nghTa thing ke {p < 0,05) v l toe dp sinh trudng tuyfit doi, tuang d l i va ty le song cua l u trflng giua cac nghifim thu'c.
Todn bfi so ligu duac trinh bay dudi dgng gid trj trung binh (TB) ± sai so chuin (SE).
111. K E T Q U A NGHIEN COU VA T H A O L U A N 1. Dien b i l n cdc y l u t l moi trudng
Nhin chung eac y l u t l mfii trudng nhu nhiet dfi nudc {28,4 ± 1,2), ham luang oxy hfia tan (7,1 ± 0,5), pH (7.3 - 8,5). ham luong NH^ (< 0,15 mg/L) vd H^S {< 0,02 mg/L), dp man {27 - 30%o) d i u nam trong pham vi thich hp'p cho sinh trudng, phdt triln vd ty Ip song cua au trung hau Thai Binh Duong [5], [7],
2. Anh hirdng cua m$t do irang len sinh trudng ve chieu cao cua au trijng hau
Kit qua nghien cfl'u cho thay, mat dfi uang cfi anh hudng Idn den sy sinh trudng cfla au tning hdu tam bfii Thai Binh Duong. Au tning duac uong d mgt dfi 1 con/ml vd 3 con/ml dgt kich thudc Idn nhit (301,20 ± 3,67 pm va 294,30 ± 4.01 pm). tiep theo d mgt dfi 5 con/mi (279,05 ± 5.28 pm), thip nhat d mgt dp 7 con/mi (263,14 ± 6,29 pm) (p < 0,05, hinh 1).
Tuy nhien, khong eo sy khae bipt thong ke ve kich thude hdu giO'a cdc mgt dp uong 1 va 3 con/ml hay 5 va 7 con/mi (p > 0,05).
a m i l d$ iraug ISn smh tnTong ciia ^u triing b i u 3. Anh hudng cfla mgt dp uong len toe dp sinh trudng tuy#t dol cua l u triing hau
K i t qua nghifin cfl'u cho thay, mat do uang co anh hudng rfi ret den t i c dp sinh trudng tuyfit doi (AGR) eua au trflng hdu tam bpi Thdi Binh Duong, Sau 15 ngdy thi nghiem, t i e dfi sinh tnrdng tuyfit doi
dgt dup'c cao nhit d mdt dfi uong 1 vd 3 con/ml (27,04 vd 26,13 ^ni/con/ngdy). tilp theo Id mdt d$
uong 5 con/ml {21,52 pm/con/ngay) vd thip nhat d mdt dfi uang 7 con/mi (17,25 pm/con/ngay;
p < 0,05, hinh 2).
Uinh Z. Anh hinhig mSt d^ inrag len t6c d$ sinh tririhig tuyft doi ciia ku trnng h i u Cac ky tu cha cat Iten cac cpl Ike hifn sfr khac nhau cd y nghm thing ke(p<0.05)
4. Anh huong cua mat dp len toe dp sinh tnrdng tuo-ng doi cua l u trung hdu
Hinb 3. Anh hudng mat dg len toe dg sinh (rudng tuomg doi cua au trung hau
Cdc ky tlf cha cai tren cac cgl the hifn sir Hide nhau co y nghm Ihnag ki(p< 0,05)
Tuang ty nhu toe dfi sinh trudng tuygt dli, m?t dp uong cOng dnh hudng den tic dp smh trucrng tuong d l i (RGR) cua l u trflng hau tam bfii. Sau 15 ngay thl nghiem, toe dp sinh trudng tuang dli ciia l u trflng hdu dgt duoe cao nhit d mgt dp uang 1 v^
3 con/ml (58,6 vd 57,2%/ngdy), tiep theo Id mdt do uang 5 con/mi {46.3%/ngdy) vd thip nhat d mat dO uang 7 con/mi (40,9%/ngdy; p < 0,05, hinh 3).
5. Anh hirdng cfla m$t dd uo>ng len ty Ip song cOa l u triing hau
Mfit dp uong cung anh hudng den tJ lfi song cua au trflng hdu tam bpi. Theo k i t qua thi nghidm, hdu dup'c uang d mat dfi 3 con/ml cho ty lfi song cao nhat (45,2%; p < 0,05), Tuy nhien, khong co sy khde bigt thong kfi v l ty lfi song cfla hau d cdc m|l dp uang 5 con/ml so vdi cac mdt dp uong 1 con/
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Tap chi Khoa hgc - Cong nghe Thdy sdn So 2/2014
ml vd mgt dp 7 con/ml (36,5 so vdi 40,0 vd 32,2%;p > 0,05; hinh 4).
Hinh 4. Anh hurnig ciia mSt d$ uxrag ien ty if song cua au triing h^u Cdc ky III chii ren cac cpl the hifn s^r khac nhau ct
Ndng eao nang suit uong nuoi tren mpt dan vj dien tieh hay t h l tich la mpt trong nhirng dilm mau chot ndng cao hieu qua cfla nghi nuoi trong thuy sdn va da dup'c quan tdm nghien cifu bdi nhilu tdc gia, frfin nhieu doi tup'ng nufii trong do cfi hdu Thdi Binh Duong [10], [13]. Vific gia tang mgt dfi nufii cho phep ndng cao sdn luyng, tuy nhifin, dieu ndy lidn quan mat thiet d i n nhieu v l n de nhu thilt k l he thong nufii, c h l dp cho an, qudn iy moi tnfdng vd phong trtr djch benh [9], [16]. Tac dfing tifiu cyc eua viec gia tang mat dfi nuoi co t h l thiy nhu bit thudng v l tdp tinh, sfl'c khfie vd cdc hoat dpng sinh ly eua hdu, 6 nhilm moi trudng, tif do. hau de man cam vdi tdc nhdn gay bfinh, giam toe dfi sinh trudng vd t ^ l e s l n g [17].
Trong nghien ciiu hifin tgi, hdu dup'c uang d mat dp 1 vd 3 con/ml dgt kich thudc ve chieu cao, t i c dp sinh trudng tuyet d l i vd tuong d l i cao hon so vdi mfit dp uang 5 va 7 con/ml. K i t qua tuang ty vdi nghien cu'u cfla mpt so tdc gid trudc dfi tren loai hdu C. glomerata khi cho rdng mdt dp thich hp'p cho
uong giai dogn giong cfla loai hau ndy Id 5 con/L [2], [10]. Cdc tdc gid ndy deu nhgn thiy xu hudng chung rdng toe dfi sinh trudng cfla hdu ty lfi nghjch vdi sy gia tdng cua mfit dfi uong nufii. Toe dp sinh trudng chdm d cdc 16 thl nghipm uong vdi mat dfi cao hon cfi the do su cgnh tranh thfl-c dn, khfing gian sing, hdm lugng fixy hoa tan, suy giam chit luong nudc,.., Tuy nhien, giu'a hai mfl'c mdt dp 1 vd 3 con/mi khong co sy khde bifit ve cdc chi tieu sinh trudng ding thdi ty Ip song d mgt dp 3 con/mi cao hon so vdi cac mgt dfi cfin igi. Chinh vi vfiy, mgt dfi uang 3 con/ml duoc xdc djnh la thich hyp eho uong l u trflng hdu tam bfii Thdi Binh Duong vfl'a dam bao toe dfi sinh trudng, ty ip song vifa tan dgng tot dien tieh va the tieh be uang,
Tuang ty t i c dp smh trudng, mgt dfi uong cfi dnh hudng idn den ty lfi song cfla cac doi tuang khae noi ehung vd hdu noi rieng, Trong nghidn cfl'u hign tgi, l u trung hdu tam bpi uang d mgt dp 3 con/mi dat ty ie song eao han so vdi mgt dfi 1,5 va 7 eon/ml.
Nhieu nghifin cfl'u cung chl ro, nufii hdu d mat dfi cao idm gia tang nguy co egnh tranh thuc an, khong gian song, fi nhiem mfii trudng vd nhilm benh, do do. Idm gidm ty lfi song trong qud trinh uong [2], [9],
IV. K^T LUAN VA KI^N NGHj
Toe dp sinh trudng tuyfit doi vd t i c dp sinh tnrcrng tuang dfii cfla hdu dat cao nhit d mat dfi uong 1 vd 3 con/mi, tiep theo la mat dfi uang 5 eon/ml va thip nhit d mdt dp 7 con/mi. Ty ie sing cfla hdu uang d mdt dp 3 con/mi cao hon so vdi cac mat dfi uang cfin lgi {p < 0,05).
Can nghien cuu dnh hudng mpt so y l u to moi trudng nhu: nhifit dfi, hdm luyng oxy hfia tan, dfi man, mdt dp thif c an,.., ien sinh trudng va ty le sing cfla au trflng hau tam bfii Thdi Binh Duang.
TAI LIEU THAM KHAO
mngri^
1 Phiing Biy, 2007. Thi nghidm san xuat giong hau Sydney (Crassostrea glomerata Gould, 1850) Tuyen tap bSo cao khoa hpc hgi thao Dpng vat than m ^ toan quoc ian thu 5: 357-365.
2 PhungBSy, Ton Nu My Nga, 14 TTiiUt Nam, 20ii. Anh huong ciia mgt d$ nuoi den sinh truang va tyl? song ciia iu trung h3u B6 Dio Nha (Crassostrea angulata Lamarck, 1819). T?p chi Khoa hpc - Cong nghp Thuy san so 3 54-59 3, Nguyin Chinb, 2007, Vai tr6 lim sgch mfli tnrdng ciia dpng vgt thin mem {Mollusca) hai v6 {Bivalvia) Tuyen tap bao cSo
khoa hpc HOitliioB^ng vat thin mem toin quoc liin thu 5: 35-39
4 Le Minh Viin, 2007. Lgi the ciia vipc san xuat gifing hau tam bgi (triploid) hing cong nghp tii b$i (tetreploid). Tuyfin tap bio cao khoa hgc Hgi thao Dgng v|t Than mem toin quoc Iin thii 5 282-287.
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Tap chi Khoa hoc - Cong nghe Thdy sdn So 2/2014
TiSngAnh5 David, C , Chnstophcr, M P., Mana, T.M., 2011. Effects of the envuonment and culture depth on growth and mortality ig juvenile Pacific oystres in the Strait of Georgia, Bntish Columbia Aquaculture environment interactions, vol I 259-274, 6 Deng, Y.. Fu. S., Liang, F and Xie, S., 2013 Effects of stocking density, diet, and water exchange on growth and survival of
pearl oyster Pwctada maxima larvae AquaculUire International.
7 Forrest, B.M., Elmetri, I., Clark, K, 2007, Review of the ecological effects of interlidal oyster aquaculture. Prepared for Northland Regional Council, Cawthron Report No. 1275, 25.
8. Goslmg, E , 2003. Bivalve Molluscs: Biology, Ecology and Culture. Blackweil Publishmg: 442.
9. HoUiday, J.E., Allan, G.L., Nell, J A., 1993. Effects of stocking density on juvemie Sydney rock oysters, Saccostr^
co/nmerc;a/(j (Iredale iSt Roughley), in cylinders. Aquaculture, 109(1). 13-26,
10. Holliday, J E., Maguire, G.B., Nell, J A., 1991 Optunum stocking density for nursery culture of Sydney rock oystos {Saccoslrea commercialis) Aquaculture 96; 7-16
11. Jyothi v., Mallia, P.C, Thomas andP, Muthiah, 2006 Induced triploidy in the edible oyster, Crassostrea madraseiis'is\rj temperamre shock. Central Marine Fishenes Research Institute, PB. No 1603, Eraakulam North P.O., Cochin - 682 OIS India, J Mar. Biol Ass. India, 48 (2) 249-252.
12 Mazon-Suastegui, J., Ruiz-Ruiz, K, Parres-Haro, A., and Saucedo P.E, 2008. Combined effects of diet and stocking densi^
on growth and biochemical composition of spat of the Cortez oyster Crassostrea corleziensis at the hatchery. Aquacuibire, 248 (1-4): 98-105.
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i4. Nell, J. A.. Cox. E,. Smith, 1. R., & Maguire, G. B , 1994 Studies on triploid oysters in Australia. 1. The farming potential of tnploid Sydney rock oysi^rs Saccoslrea commercialis (hsAaAe andRoughley) Aquaculture, 126 (3 -4): 243-255.
15. Nell. J. A , 2002. Farming triploid oysters. Aquaculture. 210: 69-88
16. Rico-Villa, B., Pouvreau, S and Rohert, R., 2009, Influence of food density and temperature on ingestion, growth and settlement of Pacific oyster larvae, Crassostrea gigas. Aquaculture Volume 287, Issues 3-4 395-401.
17. Stanley, J.G , H. Hidu, and S.K. Allen Jr, 1984. Growth of Amencan oysters increased by polyploidy induced by blocking meiosis 1 but not mciosis n. Aquaculture 37 147-155.
lo. Tanyarosa, S., Pattanatonga, T, Tarangkonna, W., 2012. Effect of water flow rate and stocking density on nursisg hatchery-reared juvenile oysters, Crassostrea belcheri in a semi-closed recirculation system Journal of Apphed Aquaculture, 24(4) 356-365
19. Taylor J.J„ Rose R.A., Southgate RC, Taylor CE., 1997. Effects of stocking density on ^owth and survival of early juvemie silver-lip pearl oysters {Pinctada maxima Jameson), held in suspended misery culture. Aquaculture, 153 (1): 41-49,
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