DoSn Trin Tan Dao vo e t g Tap chi KHOA HOC & CONG NGHE 123(09): 83 - 87
ANH H l / d N G CIIA MAT DO iTONG LEN SINH TRlTCfNG VA TY LE SONG CUA HAU TAM BQI THAI BINH DlTONG (Crassoslrea gigas Thunberg, 1793) GIAI DOAN GIONG
Doan TrSn T^n Diio' , Tr3n Vgn Dung^
'Vien Nghien ciht Nuoi trong Thuy sdn 111 Trudng Dai lioc Nlia Trang TOM TAT
Trong nghifin ciiu nay, 4 mat do uong (3, 6, 9, 12 con/lit (L)) dugc thii nghifim nham tim ra mat do thich hgp cho uong hdu gidng tam boi Thai Binh Duong. Ket qud nghien ciiu cho thay, toe do sinh trudng tuyet ddi va toe dfi sinh trudng tucmg ddi ciia hau dugc uong d mat dp 3 va 6 con/L cao hon so vdi mat dp 9 va 12 con/L (p < 0,05). Tuy nhifin, khong co su khac biet thdng ke ve cac chi tifiu nay d cdc mat dp uong 3 vd 6 con/L hay 9 vd 12 con/L (p > 0,05). Ty le song ciia hau uong d mat do 3 con/L cao hon so vdi mat do 9 vd 12 con/L (p < 0,05), tuy nhien, khdng c6 sir khac bifit ve ty lfi sdng d cdc mat do uong 6 vd 9 con/L (p > 0,05). Tir nghien cim nay co the nhan thay, mat dp thich hgp cho uong hau gidng tam bpi Thai Binh Ducrng la 6 con/L nhSm dam bao toe do sinh truong, ty lfi sdng cung nhu tan dung tot the tich be uong
Tir khda: hdu Thdi Binh Duong, Crassoslrea gigas, mat dg. lam bdi, tdc do sinh tru&ng, ly li sdng DAT VAN DE
Hau Thai Binh Duong la loai ddng vat than mfim thugc Idp hai mdnh vd (Bivalvia) cd gia tri kinh te cao, thjt thom ngon va dugc nhieu ngudi ua chudng, Hau Thai Binh Duong phan bd chii yfiu d viing bifin Thai Binh Duong, Tuy nhifin, chiing la loai rdng nhiet (0 - 36°C) va rgng mudi (5 ~ 40%o) [7], Do dd, chung dang dugc di nhap va nudi d nhieu qudc gia tren the gidi trong dd cd Viet Nam, Thit hau cd gia tri dinh dudng cao vdi ty le protein 45 - 75%, lipid 7 ~ 11% trong vat chat khd, giau axit beo khdng no va axit amin khdng thay the, giau vhamin va khoang chat [12, 14]
Hau da va dang dugc su dung nhu la mdt loai th\rc pham bd sung dinh duong can thifit, giiip phat trien chieu cao va tang cudng sinh luc cho nam gidi,... Ngoai ra, nudi hau cdn cd y nghia quan trgng trong vific giai quyet d nhiem moi trudng nudc nhd kha nang an Igc cac chat hun ca trong mdi trudng ciia loai dpng vat than mfim nay [3].
Tuy nhifin, hau ludng bgi thudng gay sau khi sinh san lam dnh hudng rat ldn den chat lirgng thjt, ty le thjt trfin vd thap, tdc do sinh trudng ch^m, ty le sdng thap De khdc phiic
tat ca nhung nhugc difim tren, rat nhifiu nha khoa hgc trfin thfi gidi da nghien ciru va tao ra ddng hau tam bgi nhdm nang cao ty le sdng, tdc dp sinh trudng, ly le thit trfin vd,,,, [8]
Cac phuong phap tao ddng tam bdi phd bien la sii dung cac tac nhdn hda hgc, vat ly va sau dd nhdn gidng chgn Igc [4, 11]. O Viet Nam, ngay tir khi nhap ve nudi thu nghifim, hau Thai Binh Duong da nhanh chdng thich iing tdt trong dieu kien nudi d cac thiiy vuc nudc Ig man, dac biet la khu vyc mien Bac va Trung nudc ta [1,2]
Tuy nhien, do hau Thai Binh Duong khdng phai la loai ban dia nfin viec nudi thuang pham hoan todn phu thudc vao ngudn gidng nhan tao [4]. Chinh vi vdy, viec nghien ciru hoan thifin quy trinh sdn xudt va uong gidng giif vai trd het siic quan trong gdp phan phat trien nghe nudi hau d nudc ta [1]. Kfit qua uang gidng hau phu thudc vao rat nhieu yeu to nhu thiic an, nhiet dg, do man, mat do uong, ,. Trong dd, mat dp uang la mgt trong nhirng yeu td quan trgng anh hudng Idn den sinh trudng, phat trien va hieu qua kinh te ky thuat ciia nghe uang nudi hdu [2, 5, 6, 15].
Viec gia tang mat dg uong giiip tan dung tdt dien tich nudi, gia tdng hieu qua kinh te, tuy nhien. nd lai di kfim vdi nhifiu rin ro nhu lam 83
Doan Tran Tan Dao vd Dig Tap chi KHOA HQC & CONG NGHE 123(09): 83-87 giam tdc do sinh trudng, ty le song, kha nang
khang benh, dac biet trong dieu kien uong nudi vdi mat do cao [9, 10]. Tuy theo giai doan phat trien ma hau thudng dugc uong d cac mat do khac nhau [10, 16]. Nghien ciiu dugc thyc hien nhdm xac dinh mat do uong phu hgp gdp phan nang cao tdc do sinh trudng, ty le sdng va hieu qua uang hau gidng Thai Binh Duong d nudc ta.
VAT LIEU, PHUONG PHAP NGHIEN CUU Vat liiu vd phuang phdp bo tri thi nghiim Nghien ciru dugc thyc hien tai Phdng Sinh hgc Thuc nghiem Vien Nghien ciru Nudi trdng Thiiy san III tir 15.03 - 05.04.2011 tren ddi tugng hau tam bdi Thdi Binh Duong (^Crassoslrea gigas TYinnhtTg,, 1793).
Ngudn hau thi nghiem: Hau gidng dua vao thi nghiem la nhihig ca the hau bam don cd kich thudc trung binh 1,00 - 1,75 mm chieu dai va 2,00 - 2,50 mm ve chieu cao. Con gidng dugc chgn la nhirng ca the khde manh, ddng dfiu vfi kich cd va khdng nhifim benh.
Mat dp uong: Nghien ciru anh hudng cua mat dp uong len sinh trudng va ty le sdng cua hau gidng tam bdi dugc tifin hanh d 4 nghiem thiic 3, 6, 9 vd 12 con/li't (L). Thdi gian thi nghiem la 50 ngay. Tat ca cac nghiem thirc thi nghiem dugc thuc hien vdi 3 lan lap cimg thdi diem.
Dung cu thi nghiem: Hau gidng dugc uong trong xd nhua hinh trdn (10 L) dugc cdp nudc vdi the tich 8 L/be. Nudc bien sir dung dugc loc sach vdi cac thdng sd mdi trudng dugc duy tri trong pham vi do man 28 - 30%o; pH 7,5 - 8,2; nhiet do 27 - 29''C va sue khi 24/24h.
dam bdo oxy hda tan tren 6 mg/L. Toan bg he thdng bfi uong dugc ddt trong nha cd mai che nham dn dinh cac yeu td mdi trudng.
Thiic dn va che do cho dn: Thirc an cung cdp cho hau gidng trong qua trinh uong la hdn hgp tao don bao dugc nudi sinh khdi Nannochloropsis oculata, Isochrysis galbana vd tao bien thu ngoai ty nhifin. Cho an ngay 2 ldn, budi sang 7 - 8 gid va chieu 1 4 - 1 6 gid.
Lugng tao cung cap vao be uong dugc duy tri trong khoang 20 - 30 trieu te bao/mL.
84
Quan ly cac yfiu to moi trudng: Cac yeu to mdi tnrdng nhu nhiet do nudc, ham lugng oxy hda tan (do 1 ngay/ldn), pH, ham lugng NH3 va HjS (do 10 ngay/lan) dugc kifim tra dinh ky bang cac dung cu (nhiet ke, test oxy, pH, NH3 va H2S) va duy tri trong pham vi thich hgp vdi su sinh trudng va phat trien ciia hau. Hang ngay, ve sinh, loai bd chat thai va hau chet nham ngan ngira tac nhan gay bfinh.
Phuang phdp thu thap vaxulyso liiu Tdc do sinh truang tuyet ddi va tuong ddi cua hau dugc xac dinh dinh ky (10 ngay/lan) bang each thu ngau nhien 30 con trong mdi nghifim thirc, sau dd tifin hanh do bang thudc kep cd dd chinh xac 1 mm. Ty le sdng ciia hau dugc xac dinh sd lugng hau cdn sdng tai thdi difim ket thiic thi nghiem.
Tdc do sinh trudng tuyet ddi AGR (mm/con/ngay) va RGR tuong ddi (%):
,^„ L2-L\ ,
RGR
(mm/con/ngay) T2-T\
Ll-L\
L\
- X 100(%) Trong do: Ll, L2 - Chieu cao cDa hau d thdi diem T l , T2 (mm);
Tl, T2 - Thdi diem do kich thudc hau ldn trudc va sau (ngay).
Ty le sdng (%) = (Sd hau tai thdi difim kfit thuc thi nghiem/sd hau ban dau) x 100 Cac sd lieu dugc xOr ly bang phan mfim SPSS 16.0. Sit dung phuong phap phan ti'ch phuang sai mgt yeu td (oneway - ANOVA) va phep kiem djnh Duncan dfi so sanh sy khac biet cd y nghTa thong ke (P < 0,05) ve toe dd sinh trudng tuyet ddi ty le sdng ciia ca giua cac nghiem thiic thi nghiem. Toan bg sd heu dugc trinh bay dudi dang gia tri trung binh (TB) ± sai sd chuan (SE).
KET QUA NGHIEN CUU VA THAO LUAN Diin bien cdc yeu to mdi truang Nhin chung cac yfiu td mdi trudng nhu nhi?t do nudc (28,4 ± 1,2), ham Urgng oxy hda tan (7,1 ± 0,5), pH (7,3 - 8,5), ham lugng NH3 (<
0,15 mg/L) vaH2S(< 0,02 mg I do man (27
Dodn Trdn Tdn Dao vd Dtg Tap chf KHOA HOC & CONG NGHE - 30%o) deu nam trong pham vi thich hgp cho
sinh tmdng, phat trien va ty lfi sdng ciia hau giong Thai Binh Duong [5, 7].
Anh hu&ng cua mat do uang len ty le song cua hdu gidng
Mat dg uong cung anh hudng dfin ty le sdng cua hau giong tam bdi. Theo kfit qua thi nghiem, hau dugc uong d mat do 3 con/L (95,8 ± 4,2) cho ty le sdng cao hon so vdi cac mat do uong 9 con/L (86,1 ± 6,7%) va 12 con/L (81,1 ± 6,1%; p < 0,05), Tuy nhifin khdng cd sy khac biet thdng ke ve ty le sdng ciia hau d cac mat do uong 3 con/L va 6 con/L (92,8 ± 5,2%) hay mat do uong 6 va 9 con/L (p > 0,05; Hinh 1).
d cac mat do 3 va 6 con/L hay mat do 9 va 12 con/L (p > 0,05; Hinh 2).
Hinh 1. Anh hu&ng cua mgl do uang len ly le sdng ciia hdu giong
Cdc ky tu chir cat tren cdc cot thi hien su khdc nhau CO y nghfa thdng ki (p < 0.05) Anh hu&ng cua mat dp uang lin sinh truang tuyet doi ciia hdu giong
Ket qua nghifin ciru cho thay, mat do uong cd anh hudng rd ret den tdc do sinh trudng tuyfit ddi (AGR) cua hdu gidng tam bgi Thai Binh Duang, vdi xu hudng chung la mat dp uang thap hon cho tdc dp sinh trudng tuyfit doi cao han.
Sau 50 ngay thi nghiem, tdc dg sinh trudng tuy?t ddi ciia hau dugc uang d mat dg 3 con/L va 6 con/L (0,651 ± 0,027 va 0,555 ± 0,024 mm/con/ngay) cao hon so vdi mat dp uong 9 con/L va 12 con/L (0,389 ± 0,031 va 0,335 ± 0,036 mm/con/ngay) (p < 0.05). Tuy nhien, khdng cd sy khac biet thdng ke \ e tdc dp sinh trudng tuy?t ddi giiia hau dugc uong
Thn gun t h nghwm Ingiy)
Hinh 2. Anh hu&ng mat do uong len sinh tru&ng tuyet ddi cua hdu giong Cdc ky tu chit cdi tren cdc cdt the hiin su khdc
nhau cdy nghTa ihdng ki (p < 0,05) Anh hu&ng cua mat dp lin sinh truang tuang doi ciia hdu gidng
Tuong ty nhu tdc dp sinh trudng tuyfit ddi, mat dg uong cung anh hudng den tdc do sinh trudng tuong ddi (RGR) ciia hau gidng tam bpi. Tdc do sinh trudng tuong ddi ciia hau gidng dugc uong d mat dd 3 vd 6 con/L (59,5
± 3,0 va 55,7 ± 3,3%)) cao hon so vdi mat dg 9 va 12 con/L (42,7 ± 2,43 va 39,1 ± 4,8%) (p
< 0,05). Tuy nhifin, khdng cd su khac biet vfi chi tieu nay giiia cdc nghiem thuc 3 va 6 con/L hay 9 va 12 con/L (p > 0,05; Hinh 3).
%
T)i(n gun Ihinghltffl (ngiy)
Hinh 3. Anh hu&ng mdl dd uang lin smh iruang tuang ddt cua hdu gidng Cdc ky' tu chit cdi trin cdc cgt the hien su khdc
nhau cdy nghia thdng ke (p < 0,05) 85
Doan Trdn Tdn Dao va Dig Tap chi KHOA HOC & CONG NGHE 123(09): 8 3 - 8 7 Thao luan chung
Nang cao nang suat uong nudi tren mgt dan vi dien ti'ch hay the tich la mgt trong nhQng diem mau chdt nang cao hieu qua cua nghe nudi trdng thuy san va da dugc quan tam nghien ciiu bdi nhieu tac gia, tren nhifiu ddi tupng nudi trong do cd hau Thai Binh Duong [10, 13]. Viec gia tang mat do nudi cho phep nang cao sdn lugng, tuy nhifin, dieu nay lien quan mat thiet den nhieu van dfi nhu thiet ke he thdng nudi, che do cho an, quan ly mdi trudng vd phdng trir dich benh [9, 16]. Tac ddng tieu cue cua viec gia tang mat do nudi cd the thay nhu bat thudng ve tap tinh, sire khde va cac hoat ddng sinh ly ciia hau, d nhiem mdi trudng, tir dd, hau dfi man cam vdi tac nhan gay benh, giam tdc do sinh trudng va ty lfi sdng [17].
Trong nghien ciru hien tai, hau dugc uong d mat dp 3 va 6 con/L dat tdc do sinh trudng tuyfit ddi va tuang dpi cao hon so vdi mat do uong 9 va 12 con/L, Ket qua tuong ty vdi kfit qua nghien ciru cua mdt sd tac gia trudc dd tren loai hau C, glomeraia khi cho rang mat do thich hgp cho uong gidng loai hau nay la 5 con/L [2, 10]. Cac tac gia nay deu nhan thay xu hudng chung rang tdc do sinh trudng ciia hau ty le nghich vdi sy gia tang cua mat do uong nudi. Tdc do sinh trudng cham d cac Id thi nghiem uong vdi mat do cao han cd the do sir canh tranh thiic dn, khdng gian sdng, ham lugng dxy hda tan, suy giam chat lugng nu'dc,,., Tuy nhien, giu'a hai mii'c mat do 3 va 6 con/L khdng cd sy khac biet ve cac chi tieu sinh trudng ciing nhu ty le sdng, Chinh vi vay, mat dp uang 6 con/L dugc xac djnh la thich hgp cho uong hau gidng tam bdi Thai Binh Duong vira dam bao tdc do sinh trudng, ty le song vira tan dung tdt dien tich va the tich be uong,
Tuong tu tdc do sinh trudng, mat do uang cd anh hudng Idn dfin ty le sdng ciia cac doi tugng khac ndi chung va hau ndi rieng.
Trong nghien cuu hifin tai, hau gidng tam bdi uang d mat dp 3, 6 con/L cho ty le sdng cao 86
han so vdi mat dg 9 va 12 con/L. Nhieu nghien ciru ciing chi rd, nuoi hau a m^t dp cao lam gia tang nguy co canh tranh thiic an, khdng gian sdng, d nhiem mdi trudng va nhiem benh, do do, lam giam ty le sdng trong qua trinh uong [2, 9].
KET LUAN VA KHUYEN NGHI T6c do sinh trudng tuyet ddi va tdc do sinh trudng tuong ddi ciia hau dugc uang d mat do 3 va 6 con/L cao hon so vdi mat do 9 va 12 con/L. Khdng cd sy khac biet thdng ke vfi cac chi tieu nay d cac mat do uang 3 va 6 con/L hay 9 va 12 con/L. Ty le sdng ciia hau uang d mat do 3 con/L cao hon so vdi mat do 9 va 12 con/L.
Cdn nghien cuu anh hudng mgt sd yeu td moi trudng nhu: nhiet do, ham lugng oxy hda tan, do man, mat do thirc an,... len sinh trudng va ty le song ciia hau tam bdi Thai Binh Duang giai doan gidng.
TAI LIEU THAM K H A O Tdl lieu tiing Viit:
1. Phimg Bay (2007). Thir nghiem san xuat giong hau Sydney {Crassoslrea glomeraia Gould, 1850).
Tuyfin tap bao cao khoa hpc hfii thao Dpng vat thdn mem toan qudc lan thir 5, trang 357 - 365, 2. Phiing Bay, Ton Nu MJ Nga, Lfi Thj Ut Ndm (2011). Anh hudng ciia mat dp nudi dfin sinh tnrdng va ty lfi song ciia au trung hau Bo Dao Nha {Crassoslrea angulata Lamarck, 1819). Tap chi Khoa hpc - Cong nghfi Thuy sdn sfi 3, trang 54 - 59.
3. Nguyfin Chinh (2007). Vai tro Idm sach moi trudng ciia ddng vat than mfim (Mollusca) hai vd (Bivalvia). Tuyfin tap bao cao khoa hpc hoi thao dfing vdt than mfim toan qudc ldn thir 5, trang 3 5 - 3 9 .
4 Le Minh Vien (2007). Lgi thfi ciia viec san xuSt gidng hau tam bdi (triploid) bdng cdng nghfi tii bpi (tetreploid). Tuyen tap bao cao khoa hpc Hpi thao Dong vat Than mem toan qudc ldn thii 5, trang 2 8 2 - 2 8 7 .
Tdi lieu tieng Anit:
5. David, C„ Christopher, M.P., Maria, T.M. (2011).
Effects of the environment and culmre depth on grovvth and mortality in juvenile Pacific oystres in the Strait of Georgia, British Columbia. Aquaculture environment interactions, vol. 1 2 5 9 - 2 7 4 . 6. Deng, Y., Fu, S., Liang, F. .m ! Vie, s. (2013).
Effects of stocking density, ,i a n j ^gtgr
Dodn Trdn Tdn Dao vd Dtg Tap chi KHOA HOC & CONG NGHE 123(09): 8 3 - 8 7 exchange on growth and survival of pearl oyster
Pinclada maxima larvae. Aquaculture Intemational.
7. Forrest, B.M., Elmetri, I., Clark, K. (2007).
Review of the ecological effects of intertidal oyster aquaculture. Prepared for Northland Regional Council. Cavrthron Report No. 1275,25p.
8. Gosling, E. (2003). Bivalve Molluscs' Biology, Ecology and Culture. Blackwell Publishing. 442 pp.
9. Holliday, J.E„ Allan, G.L., Nell, J A (1993).
Effects of stocking density on juvenile Sydney rock oysters, Saccoslrea commercialis (Iredale &
Roughley), in cylinders. Aquaculture, 109 (1): 13-26, 10. Holliday, J.E., Maguire, G.B,, Nell, J.A.
(1991). Optimum stocking density for nursery culture of Sydney rock oysters {Saccoslrea commercialis). Aquaculture 96, 7-16.
11. Jyothi v . , Mallia, P . C , Thomas and P., Muthiah (2006). Induced triploidy in the edible oyster, Crassoslrea madrasensis by temperature shock. Central Marine Fisheries Research Institute, P,B No. 1603, Emakuiam North P.O., Cochin - 682 018 India, J. Mar. Biol. Ass. India, 48 (2): 2 4 9 - 2 5 2 .
12. Mazon-Suastegui, J., Ruiz-Ruiz, K,, Parres- Haro, A., and Saucedo P.E, (2008), Combined effects of diet and stocking density on growth and biochemical composition of spat of the Cortez oyster Crassoslrea corieziensis at the hatchery Aquaculture, 248(1-4): 98-105,
13. Monteforte, M., Bervena, H., Ramirez, J.J., Saucedo, P., and Lopez, C O . (2005), Effect of stocking density on growth and survival of the rainbow pearl oyster Pteria sterna (Gould 1852) during nursery and late culture in Bahia de La Paz, Baja California Sur, Mexico. Aquacuhure Intemational, 13 (5): 3 9 1 - 4 0 7 .
14. Nell, J. A., Cox, E., Smith, [. R., & Maguire, G. B. (1994). Studies on triploid oysters in Australia. 1. The farming potential of niploid Sydney rock oysters Saccoslrea commercialis (Iredale and Roughley). Aquaculture, 126(3 - 4 ) , 2 4 3 - 2 5 5 ,
15. Rico-Villa, B., Pouvreau, S. and Robert, R (2009). Influence of food density and temperature on ingestion, growth and settlement of Pacific oyster larvae, Crassoslrea gigas. Aquaculture Volume 287, Issues 3-4, Pages 395-401.
16. Tanyarosa, S., Pattanatonga, T., Tarangkonna, W. (2012). Effect of water flow rate and stocking density on nursing hatchery-reared juvenile oysters, Crassostrea belcheri in a semi-closed recirculation system. Joumal of Applied Aquaculture, 24 (4): 356 - 365
17 Taylor J.J,, Rose R A , Southgate P C , Taylor C E . (1997), Effects of stocking density on growth and survival of early juvenile silver-lip pearl oysters, Pinctada maxima (Jameson), held in suspended nursery culture Aquaculture, 153 (1):
41-49, S U M M A R Y
E F F E C T O F R E A R I N G D E N S I T Y O N G R O W T H A N D S U R V I V A L R A T E O F T R I P L O I D P A C I F I C O Y S T E R S E E D
(Crassostrea gigas T h u n b e r g , 1793)
Doan Tran Tan Dao'', Tran Van Dung' 'Research histiliiie for Aquaculture No 3.' Nha Trang University In this study, four densities 3, 6, 9, 12 ind./liter (L) were experimented in order to identify a suitable density for rearing triploid Pacific oyster from the stages of fry to fingerling. Results showed that absolute growth rate and relative growth rate of the oyster reared at the density of 3 and 6 ind./L were significantly higher than those of the density 9 and 12 ind./L (p < 0.05).
However, there were no significant differences about these parameters within the densities of 3 and 6 ind./L or 9 and 12 ind,/L (p > 0.05). The survival rate of the oyster reared at density of 3 ind./L was higher than those of the densities 9 and 12 ind./L (p < 0,05), however, there was no significant difference about survival rate between the densities of 6 and 9 ind,/L (p > 0,05), From the results of this study, it can be suggested that the appropriate density for rearing the triploid Pacific oyster from the stage of fry to fingerling was from 3 - 6 ind /L in order to optimize the growth, survival rate and tank rearing squares.
Key words: Pacific oyster. Crassoslera gigas, density. gro-n>lh rate, survival rale, triploid Ngdy nhgn bdi04/l 0/2013: Ngdy phan bi?n 11/11/2013: Ngdy duyil ddng 20/8/2014 Phdn biSn khoa hoc: GS TS Tir Quang Hiin - Dgi hoc Thdi Nguyen
