Kỹ thuật nuôi giáp xác

Ngh0 nu6i giSp x6c chir y6u li nu6i t6m he khcri dAu 0 khu vuc D6ng Nam A vdi hinh thtc nu6i quang canh trong cilc ao dAm tU nhiOn ven bi6nhodc vtrng nmg ngflp m{n, cta song,bing rrgu6n

BIEN SOA.N

C6 TS Ta Kh[c Thudng Da hoc Thfiy sin

Th.S Luc Minh Di6p Dai hoc Thriv san

TS Neuy6n Th! Bich ThriY ViQn Nghi€n cuu NTTS III Chuone III

Th.S TrAn Neoc Hii Da hoc Cin Tho

Th.S Nsuv6n ThiHdng Vdn Dai hoc Ciin Tho

4 Hem lugng oxy hda tan ' ' 68

5 Hqp ch6t nito ' 68

6 HzS 68

7 D9 cimg (total hamess) vi ttQ kiAm (Alkalinity) .' ' '.' 68

phdn 2: Kt THUAT IINH siN xnAN r4o rdM H8 ' 71

r rHrET KE VA HOAr DQNG Tp,5I SAN 1UAT rflM GI6NG mrAN TAo .7t 1 Chqn vi tri vi mflt bang xny dpg tr4i sdn xu6t t6m gi6ng 7l 2 Quy m6 tr4i vi c6c y6u cAu thitit ki5, thi c6ng, xtr ljr sau lrtri xdy dUng "'72 rr KY rHUAr XU Lv NLTOC 7e rrr KY rHUAT TUYEN 6HQN T$M eo IyIE, r.n-lflr v6 v.q cHo DE 81

1 Ngu6n t6m bO me vi phuong ph6p tuyOn chqn .' "' 81 rv KV rHUAT LIONG r.n-ror AU TRUNG ToM HE ' 90

1 Chu6n bi b€ ucrng :' - ' 90

2 BO tri mft ttQ 6u trung trong b0 uong ' ' 9l 4 Quan lf m6i truong bO uong vi phdng tri benh .102

5 Theo d6i tinh tr4ng sric khoe 6u trung vi di6rr bii5n tinh hinh bi5 nu6i 103

v THU HOACH VA VaN CHUYEN 104

4 -

-

1 phin i: Kfr rHUAr NUdI rilu run THUfiNG PHAM 107

r CAC uiNH THUC r.n-l$r 107

1 NuOi quing canh truyAn th6ng vi quang canh cii tii5n 107

2 Nu6i ban thAm canh - 108

3 Nu6i th6m canh 108

rr KY rHUAT m-rOl rOM HE THUONG PHAM 112

1 Chgn ving nu6i .112

3 XXy dpg c6ng trinh nu6i 113

5 The gi6ng : 121

6 Xic dinh t6c d0 sinh truong vi ti lQ s6ng ' 123

7 Ky thuflt cho An : '."' ' -.-.- - 124

9 Phdng tri benh t6m nu6i : 144

10 Thu hoach 148

cHLfcrNG rrr: Ki THUAr NUOI r6u uunn lsl

1 Phan lo4i vi hinh th6i 151

2 D{c di6m ph6n bO .152

3 D6c di6m sinh truong .154

4 Ddc tliOm sinh s6.n 156

rr KY rHUAT m-lor rou HUM rHuoNG PHAM 160

1 C6c dqng l6ng nu6i 160

2 Chqn vi tri nu6i .162

3 Chgn gi6ng vi ucmg t6m con 162

4 Quan lf vi chdm s6c t6m nu6i 163

5 Thu ho4ch 163

rrr TRrEN VQNG CUA NGHE r.U-lOr roU HUM GAI 163

CHIIONG IV: KY THUAT NUOI TOM CANC XANH THTIONG PHAM .,., 167

r Gror rHrEU 167

rr DAc DrEM srNH HQC CUA roU CANG XANH 167

1 Phan lopi vd hinh th6i 167

2 Phan b6 169

3 Vdng ttdi ctra t6m cang xanh 170

4 Dac di6m sinh truong 170

5 D{c di6m sinh sin 171

6 YOu ciu vC m6i trudng s6ng 171

7 Nhu cAu dinh du0ng ctra t6m 172

rrr KY rHUAT IJONG NUor roU CANG XANH r72 1 Llcrng t6m gi6ng 172

2 Nu6i t6m thit .174

CHTIONG V: KV THUAT NUOI CUA BIEN 179

I GIoI THIEU ; 179

II MOT SO DAC DIEM SINH HQC CHINH CUA CUA 8IEN 180

l Hinh th6i, phtn lo4i, phln b6 ' ' 180

Z.Dlc iliOm sinh tru&ng, lQt x6c vi t6i sinh ' 183

3 DEc tti6m dinh du0ng '.' 184

5 MOt sO a{c di6m sinh th6i cta cua bi6n ' 189

rrr KY rHUAT SAN XUAr GIONG 190

1 K! thuft sinh san nhdn t4o 190

2.Ky thuft vf,n chuytin vi khai th6c Megalopahay cua bQt/gidng .' 196

1 K! thuft nu6i chuy0n cua con thd,nh cua thit 198

2.Ky'thuflt ning cdp cua thucrng phdm 200

CHUONG vr: KY rHUAr NUor ARTEMTA 205

I GIOI THIEU ; 205

rr EAc DrEM srNH HQC CUA ARTEMTA 2:07 1 D6c di6m phnn loai 207

2 Vdng clcri ph6t tri6n vi sg sinh truong r ., 207

4.D{c ditim sinh s6n : 209

5 Kha ning thich ung vdi c6c didu kiQn m6i truong 210

1 Vei n6t vA hoat dQng ctra ruQng mu6i ve sp thich nghi cria Artemia 211

TAI LI.EU THAM rcrAO : , 230

LOI NOI DAU

icip xdc ld ldp dQng vQt thu\c ngdn( chdn khop, cd nli.iu lodi ld diii twqng

nuii quan trong cila nghi nu6i tr1ng,thity sdn NghA nu6i gidp x(c; do9biQt ngh€ nu6i t1m he, hi€n dang chiAm m6t ti trpng l6n trong nghA nuditr6ng thily sdn thd gi6i vd Vi€t Nam, cd vi sdn luqn7 va gid tri Trinh d0 W thugt nu6ithrty sdn.nadc lq, mfin trong ao ddm vd tr€n biAn 6 Vi€t Nam trong thdi gian qua iluqc phdt tri€n, ndng cao, chit yAu dqra vdo cdc kdt qud nghi€n crhu, cdc kinh nghiQm tich lfiy

daqc trong qud trinh nu6i t6m he, t6m him, cua bi€n, Artemia, NghiAn c*u, tim hiAu

nhftng

"ai tiA" lQ thuQt trong linh vtgc nu6i gidp xdc sd gitip chung ta duc k€t duqc

nniii tctnn nghiQm cho viAc thig (lang phdt fiAn nu6i cdc d6i tuqng hdi sdn khdc

Hi€n tqi, tfi thuQt nu6i gidp xdc 0 nadc ta kh6ng ng"irng duqc cdi tidn ndng c.ao vdtiAp thu kinh nghiQm ct)a thf giOi K! thuQt nu6i biiin d1t hang ngdy vd phdt tri€n mQtcich da dqng tily theo diiu kiQn t*ng ving h vQy, trong pham vi cudn sdch ndy kh6ngthd cung ciip $n d7c gid tdt cd nhtrng cdi tidn W thuqt, nhtrng gidi phap W thudt ddcthr), nhing bien dil liin tqc qua tirng uu, Chilng t6i hy vgng vdi nhirng ddc diAm ciladiSt tuqn{nu6i, nhirng ngrydn ly cobdn cilng nha kinh nghiQm sdn xudt daqc trinh bdy

t:?"€ td.i li€u ydy,sd Sity

1!o bsn doc.tich lily vd hQ th6ng duqc_cdc k1!y th*c cdn thi€td€ tim hidu sdu hon vd d1i taqng, hiAu rd hon cdc qud trinh dang di€n ra trong m6i

tradng nu6i, th6ng qua dd de ddng fiAp cQn vdi bdt c1.r mQt gidi phdp lO thuqt mhi hodcm1t phuong phdp nu6i mdi ndo khdc Nhtrng rdn ai tnac khdng duqc trinh bdy tronq

cu6n sdch ndy xin d7c gid tham khao 6 cdc tdi lieu c6 li6n quan nhu: Qudn ly chdt

laqng nadc trong nu6i tring thity sdn, BAnh hOc thily sdn, C6ng trinh nu1i thily sdn,

Trong qud trinh bi€n soqn chung t6i dd st)r dung cdc tu hAu, cdc ket qqa ngli1ry

ctru vi

""di gtap xdc ct)a nhiiu tdc gia trong vd ngodi nadc Tuy nhi€n, nhiAu viin dAdagc tich ml * cdc bcii g.idng, cdc ght chep qua

"iii, thA he gidng vi€n n€n kh6ng the

trdnh khdi sq thdt lsc xu-tit *i, mra ihdn cho iie" tri"h ddn fii liQu tham khgo; ,rdt,mong

daqc sw laqng thu cita cclc tdc gid vd xin chdn thdnh cdm on MQc dil dd rdt cO gdng hAtsrhc nhang cin m\t sii vtin di-cutin sach chaa th€ cdp nhctt het Rdt mong nhQn daqcnhirng Sop i t* phia d7c gid, nhAn daqc nhftng thdnh qud nghi€n c*u vd kinh nghiQmsan idt quii bdu ae Ua sung, hodn chinh cudn sdch ndy

Chilng t6i xin chdn thdnh cdm on sW giilp ild cua.cac tradng dgi hqc, cdc viQn

nghi€n ctru, cdm CIn sU cQng tdc cila cdc tdc gid vd cdc d6ng

nghiQp-Thay m{t cic thc gih LBc Minh DiQp

Chucrng I:

I

l Gi6'i thiQu chung

Mic di dd c6 tir kh6 ltu nhmg nghd nu6i giirp xitc trOn th6 gioi chi m6i ph6t tri6ntrong vii thap kf gAn d0y TOng sin lJqng gi6p xitc nu6i ctra th6 gioi gia tdng deu dqn

tu ndm 1970 (Ilinh I.1) vd dd dat di5n con s6 1,65 triQu t6n, tri gi6 9,4 ti USD vio nlm

2000 (IrA(), 2OO2) S1r' gia tdng nhy ld k6t qui ctra vi6c mo rQng diQn tich nu6i, d6i

tuong nu6i vh gia tdng rnirc d6 thAm canh IIi0n tai c6 it nhAt ld 46 lodi gi6p x6c c.o ei1

tri thu<rng phAm dang-duqc nudi ri 70 qu6c gia trOn th6 gi6i C6c qu6c gia d6n dAu vC

sdrn luong gi6p x6c nu6i bao g6m 'l'rung .Qu6c, Ih6i Lan, Indonesia, Vi6t Nam,Ilangladesh, An f)6, licuador (Iling I.1) Ngh€ nu6i gi6p x6c dem lai lqi nhu4n c.ao, ggpph6n n0ng cao dcri s6ng cua ngudi dAn vir gia tdng kim ngach xu6t khdu cira nhi6u qudc

gia Iai ViQt Nam, gi6 tri xu6t khau t6m sri trong ndm 2000 de d$ 239,5 triQu USDfutrto, 2002) Chi fi;h riOng 6 Kh6nh IIoa nghd nu6i t6m hum l6ng xu6t khAu dd dem

l4i mQt ngu6n thu nhap hing nlm udc tinh khoang 450 ti d6ng (So Thriy sdn Kh6nhIIoa, 2002)

Ilinh I.1: Sin luqrng vi gii tri cria gi6p xic nu6i tir 1970-2000 (IIAO,2002)

Gi6p x6c (C'rustacea) li mQt trong nhflng nh6m clQng vQt c6 thdnh phAn lodi phongph(r 'l'uy nhi6n kh6ng phai loii nho cfrng c6 grb tri kinh t6 vd c6 th6 nu6i dugc trong

iieu f<iqn nhAn tao 't,ong s6 nhfrng d6i tugng nu6i, c6 lodi d6 phr,rc vu nhu ciu thuc

C6c d6i tugng giitp xfrc, dac biQt c6c tl6i tugng phin b6 cr virng nu6c lg ho{c mdn,thudmg c6 gi6 tri dinh du&ng cao Him lugng cao ctra chc axit b6o kh6ng no (highlyunsaturated fatty acid, HUFA) trong cic san phAm niy tir lfu vAn dugc xem h c6 lqi

cho sric khoe vd tri lgc cta con nguoi Trong khi d6, viQc str dung 6u trung ctra c6c lo4igiep x!rc nho nhu Artemia lim thric 5n cho 6u trung cua chc d6i tuqng nu6i c6 gi6 trikinh tc cao (nhu c5 bi6n, t6m he) dd t4o du-o c nhirng budc nhiy vgt trong c6ng nghg san

A A

xudt con gi6ng nhln tao, k6o theo sg gia t6ng ilang kO cta san lugng gi6p x6c nu6i

Bdng L/; Sin tugng vir gi6 tri cfia nghd nu6i giip xic t4i cic qu6c gia hing tliu

tr6n th6 gi6ri trong nIm 2000 (FAO, 2002)

303.430146.82396.43364.64852.77150.94046.8t933.53025.243

17.457

15.923

11.390

10.3648.50056.354

2.137.615861.799521.892393.938302.960293.2202s5.741194.333177.066134.006126.52891.120

78.343

s9.568373.569

T4i chdu M! vi ch6u Au ngh0 nu6i t6m hirm cing holc t6rn cdng nudc ngot bit

ngu6n tir nhiing thanh c6ng cta viQc thi gi6ng vio tu nhiOn 6 thap kj/ 50-60 voi muc

-: e - -?r':J .-.

-i tlich bO sung ngu6n lqi Ngh0 nu6i giSp x6c (chir y6u li nu6i t6m he) khcri dAu 0 khu

vuc D6ng Nam A vdi hinh thtc nu6i quang canh (trong cilc ao dAm tU nhiOn ven bi6nhodc vtrng nmg ngflp m{n, cta song,bing rrgu6n gi6ng tu nhiOn, c6c ttoi tugng chinh li

t6m he vi cua) ho6c nu6i ntrOt mQt thdi gian trong c6c l6ng nudi th6 so (cua, t6m htm).Mac dir v4y chi trong mQt thoi- gian ngin, nhd sg ph6t triOn nhanh ch6ng cta c6c c6ngngh6 mang tinh h5 trg (sAn xu6t gi6ng nh0n t4o, s6n xu6t thric 5n, c6ng trinh va thi6t bfnu6i) hinh thric nu6i dd duoc ning l6n quang canh cii ti6n (improved extensive), b6n

thnm canh (semi-intensive), th0m canh (intensive) vi thfm chi siOu thdm canh (super

intensive) D{c thir voi cic muong hodc b€ vdng nu6c chdy, m6t dQ nu6i vi ndng su6trdt cao nhung hinh thric nu6i siOu th0m canh thucrng kh6ng <tem l4i hiQu quA kinh tti dodAu tu c6ng trinh vi chi phi van hanh qu6 t6n k6m

Su ph6t tritlncria ngh€.nu6i mdi AOi tugng gi6p x6c php thuQc vio mdt lo4t ytiu t6:

kh6 nang gi6i quy6t con gi6ng (khai th6c tir 4r nhi6n ho{c sdn xudt nh0n t4o),-ngu6nthric 5n (tu nhi6n ho{c c6ng nghiQp), diQn tich m{t nudc phir hqp v6i y€u cAu cta rl6i

tugng, khi ndng 6p.dpng c5c ti6n b0 khoa hgc k! thuAt vio x6y d1mg, van hanh vi quan

llf c6ng trinh, hQ th6ng nudi vd khi ning kii5m so6t dich bpnh grrg v6i nhirng hiQu qud

kinh ti5 to l6n mi n6 dem l4i, ngh6 nu6i giirp xitc cfing tao nOn nhirng m6i lo ng4i vC m6itrunng vi b6o vQ ngu6n fqi iht y sdn Vi[c pnat tri6rlf,ii5u qui ho4ch t6ng th6 vd c6c th6cfr6 quan lf thich hqp c5c khu nu6i t6m t4i nhi6u qu6c_ gia dd k6o theo mQt loqt nhirng

u6, ,an nhu ch{t ph5 rimg ngflp min, thoii h6a d6t dai,.6 nhi6m m6i trucrng cuc bQ,tranh ch6p tdi nguy0n it6t, nudcvli cilc ho4t dQng kinh t5 kh6c ViQc su dpng c6 t4p

ldm thric 6n cho c6c d6i tyqng gi6p xhc nu6i g6p ph6n gia tdng 6 nhi6m m6i trudng vi

lan trim dich benh Ngay cA khi thrlc 6n c6ng nghiQp c6 hdm luqng qjot:tl cao dugcdirng, 6p lpc khai th6c 16n c6 bi6n ldm bQt c6 cfing sE gia tlng m4nh, din d6n nhimg longaiue-.a, kiQt ngudn lqi c6 tg nhi6n Nu6i trdng thtry san v6n dugc xem nhu li mOthoat dQng tich cUCdO b6o vQ ngudn lgi Tuy vQy, vcri nhi6u dOi tuqng nu6i khi mi con.t

glong va rnuc an con duqc khai th6c chir y6u tt [r nhiOn, 6nh hu&ng ctia nu6i tr6ng thriy

i* t0n ngu6n lqi tU nhi6n lai diSn ra theo chi6u hudng ti6u cpc

'l

DO c6 thd ph6t huy hOt c6c ti6m ndng cira ngh€ nu6i gi6p xhc, c6c v6n d0 n6u tr6n

phii duqc giai quy6t Ot r6.h thoa tlang vd d6ng bQ Cfrng gi6ng nhu t6t ch chc ho4tdQng kinh tt.f.fra., ngh6 nu6i gi6p xhc dang timg bu6c ph6t tri6n vd tg hoin thiQn minh

Tru6c nhu cAu ngiy cing tdng cira xd hQi vi 6p lgc crta chc t6 chfc bio vQ m6i trulng,

tii nguydn thi6n nhi6n, viQc xiy dpg c6c m6 hinh hoac qui trinh cdng nghQ nu6i bOnvm{Aa"g ld trgng tdm chinh gtra nghE nu6i gi6p x6c cfing nhu cic ho4t ttQng nu6i trting

thtry san kh6c.nhlm gi6m thi6u nhimg t6c dQng m6i trudng vi dAm b6o cho sg ph6t

tri6n l6u ddi, b6n vlrng ctra ngh6

2.Eiituqng nudi

M{c du c6 it nh6t 46 lodi gi6p xitc kh6c nhau dang dugc nu6i tr0n th6 gicri (bang1.2), s6luqng c6c tl6i tugng nu6i chinh l4i kh6ng nhiOu T6m he (1huEc h9 Penaeidae) lddOi tuqne ru-Oi pfrO bi5n nh6t, chitim ti trgng cao cA vii san lugng l6n gi6 tri Trong nh6mnity, cilc d6i tuqng duoc nu6i rQng rdi ntrAt ta t6m sri Penaeus monodon vd t6m chin

trdng P vannamei (cdn gqi ld Litopenaeus vannamel Tey sri dugc nu6i o hcrn 30 qu6cgia tr0n thti gi6i (k6 ca nhirng ncri loii niy kh6ng ph6n b6 tU nhiOn) nhd vio t6c tIQ sinh

i*-rg nhanh cira n6 T6m chdn tring chri yC, duo,t.nu6i 0 c5c nu6c.thuQc tiy ban cAunhu Ecuador, Mehico, My, Venezuaela,Braztl Nhd vio nhffng ti6n b0 v0 di tnryCnchqn gi6ng me gAl diy con gi6ng sach bQnh (SPF - specific pathogen free) ho{c c6 kh6ndng kh6ng m0is6 bQnh thdng.thucrng (SPR - specifii pathogen resistance) hoac c6 t6c

dQ sinh trucrng cao cta mQt s6 ddng t6m chdn trdng vir t6m xanh P stylirostrzs (hayLitopenaeus stylirostrzs) dang dugc du nh4p vdo c6c nu6c nudi t6m 0 khu vuc chAu A(Preston & Clifford 2002) TOm he Trutg Qu6c P chinensis c6 kich thu6c thucrngphAm nho hcrn (12-l5g) vd dugc nu6i nhiiSu o Trung Qu6c (Qingyin vi ctv, 2002) m{c dr) c6 sdLn lugng tucrng d6i l6n so v6i c6c d6i tuqng kh6c nhu t6m th6 P (hayFenneropenaeus) merguiensis, t6m he NhOt Bin P (hay Marsupenaeus) japonicus, P

(hay Liiopenaeus) stylirostris ho4c t6m rin P semisulcatzs T6m the, P merguiensis

.U"g ta mQt d6i irrqng nu6i l0u ddi 0 khu vuc D6ng Nam A Tuy nhi6n chi trong vhi

,A* tro lai ddy ngh6 nu6i t6m th6 vi mQt s5 c6c dOl tuqng thuQc gi6ng Metapenaeus

mgi ttuo c quan tim nhi6u hcm khi dich bQnh vi kh6 khdn trong kh0u cung cdp con

gi6ng cho ngh6 nu6i t6m sri ngdy cdng tr0 nOn trAm trgng (Ting2001a, b) Ti0m ndng

nu6i t6m the khA l6n, d{c biqt n6u dugc thpc hiQn v6i sg trg girip cua mQt chucrng trinh

di truy6n chgn gi6ng hiQu qui (Tirng vi ctv, 2OO2).

T6m cing xanh (Macrobrachium rosenbergii) c6 th€ ducy c coi H d6i tugng t6mnu6i ph6 bi6n nh6t o c6c virng nu6c nggt Dii Loan vi Thii Lan ld c6c nu6c Adn d-Au ves6n luong trong sO +l qu6c gia tr6n th6 gioi (trong tI6 c6 ViQt Nam) dang nudi t6m cing

xanh Ctng gi6ng nhu v6i c6c d6i tugng t6m he, c6ng nghQ sin xu6t con gi6ng nhan taoill6n <linh vi mang,tinh chir dQng cao vi t6m nu6i cdn c6 ti l0 thanh thuc cao trong di6ukien nhin t4o T4i iic vi cic qu6i gia chnu Au c6 khi hdu lanh nghA nu6i c6c aOi Iuqng

tdm cing nu6c nggt (crayfish) kh6 ph6t tritin nhmg san lugng cdn rlt khi6m t6n (Lee &

gltg Portunus dang ducv c tri6n khai d kh6 nhi6u qu6c gia nhu Uc, Indonesla, Philippines,

Th6i Lan, Vigt Nam voi mgc dich thric dAy sp ph6t tri6n cria nghA nu6i c6c t16i tuqngniy (Keenan & Blackshaw,l999;Pizzuto vi ctv, 20001, Th4ch, 2002)

Nghd nu6i Artemia thu trung bio x6c v6n cdn k6m ph6t tri6n m{c dt nhu cAu r6tcao M{c di Artemia li dQng vflt du<r c.sir dgng ldm thric 5n s6ng trong nu6i tr6ng thty

sin nhtmg trung bdo x5c Artemia vi gAn ddy Artemia sinh kh6i le *at trang cO gia t4tr0n thf trucrng Nu6i Artemia lA mQt nghd mang tinh ch6t sin xu6t hang h6a cho nOnArtemia duoc xem li mQt aOi tuqng nu6i, kh6c vcri c6c sinh vft ducr c sri dpng lim thirc

[n s6ng kh6c nhu Copepoda, Daphnia, Sdn luqng trimg bio xic Artemia cria thti gioichri yi5u h tir ngu6n thu tg nhiOn (d My) (Lavens & Sorgeloos, 1996) Cic qu6c gia friqndang.nu6i Artemia thu tnmg bio x6c g6m c6: Uc, Bi, M!, Trung Qu6c, Vipt Nam UOt

s6 tl6i tuqng nu6i moi thuQc nh6m giirp xhc nhu t6m mt ni (Thenus orientalis), t6m tit(Squilla,spp), mQt sO loei kh6c thuQc ho Penaeidae (chua du-o.c nu6i nhi6u tru6c dAy)ho4c gi6ng Metapenaeas hiQn dang dugc quan tim nghiOn criu

Bdng L2: Citc toii gi6p xic.tlang tluqc nuOi tr6n th6 gitfi vi O ViQt Nam

(T6ng hqp tt s6 liQu ctra FAO vi SUMA - Danida)

MOi Loii Khi ntrngtrudng nu0i O sx giiing

nuOi VN nhin tao

Hg

(Family)

TGn khoa hgc(Scientific name)

TGn thuong phAm(Commercial name)

Penaeidae Metapenaeus dobsoni Kadal shrimp L, M

Metapenaeus endeavouri Endeavour shrimp L, M

Metapenaeus ensis Greasyback shrimp L, M

Metapenaeus manoceros Speckled shrimp L, M

Penaeus aztecus Northern brown shrimp L, M

Penaeus chinensis Fleshy prawn L, M

Penaeus esculentus Brown tiger prawn L, M

Penaeus indicus Indian white prawn L, M

Penaeus japonicus Kuruma prawn L, M

Penaeus kerathurus Caramote prawn L, M

Penaeus merguiensis Banana prawn L, M

Penaeus monodon Giant tiger prawn L, MPenaeus notialis Southern pink shrimp L, M

++

++

+++++++++++++

Penaeus paulensis

Penaeus penicillatus

Penaeus schmitti

Penaeus semisulcatus Penaeus setiferus Penaeus stylirostris

Penaeus subtilis

Penaeus vannamei

Sao Paulo shrimp

Redtail prawn

Southern white shrimp

Green tiger prawnNorthem white shrimpBlue shrimp

Shouthem brown

shrimp

Whiteleg shrimp

L,M L,M L,M L,ML,IvlL,M L,M L,M

++++++++

Xiphopenaeus kroyeri Atlantic seabob N, L, M

Sersestidae Acetes iaponicus Akiami paste shrimp M

Palaemonidae Macrobrachium

malcolmsoniiMacrobrachiumrosenbergii

Palaemon serratus

Monsoon riverprawn N, L, M

Nephropidae Homarus americanus American lobster

Homarus sammarus European lobster

MM

+

+I+(N: ntfrc nggt L: nudc lq M: nuoc mQn)

3 COng trinh vir m0 hinh nu6i

Tiry thuQc vio d{c tinh sinh hgc mi d6i tuqng nu6i gi6p xic c6 th6 dugc nu6i

trong aoinA" a6t hoac i6t nhua plastic, xi ming), ldng, ddng, UC 1xi.mdng, sgi thiry tinh,ptasiicy ho{c c6c muong nu6c ch6y (raceway) (Pillay, 1993) Ao dat la c6ng trinh nu6i

pnO Ui6n nir6t cho trAu [et c6c ddiiuqng nuoi phgc vg nhu c6u thgc phAm Kich thudc

ao nu6i thay d6i tiry theo mtic dQ c6ng nghiQph6a vi khi ndng.su a;11S a6t dai, th6ng

thuong khoang I ha/ao nhtmg c6 thiS nh6 hon (vii tr[m, vii nghin m') ho{c lon hon rdt

nhieuis-tO hata) (Fast vi Menasveta,2OOZ) Ca9 Joai nu6i lim thirc 6n nhu Dapnhia

du-o c nu6i chtr yt5u trong bC c6 kich thudc nh6 NghC mt6i Artemia thtt trimg bio x6c sri

dpng c6c ruOng mu6i g,avens vi sorgeloos, 1996) T6m hirm l4i rtugc nu6i ch6 y6u

trong ldng (chim hoac n6i) o bi6n fictr ttruoc l6ng dao dQng ttr t- 64 m3 (Sd Thtiy sanKhenh Hita,2002)

M6 hinh md sir.dpng ao thay nudc theo ctr6 Oq thtry tridu (hoic sir dgng m6y bcrm)

duoc sri dpng ph6 bitin o tdt chc6c qu6c gia c6 ngtrA nuOi gi6p xic Tuy nhl6n, do tinhhinh 6 nhi6m m6i trucrng vi d{c biet le sg lan trin cria aicfr Udnn, ga" Oay c6c m6 hinhnu6i it thay nudc ho4c t6i sy dpng nuoc dang duqc nghi0n cr?u vi img dUng o kh6 nhi6u

noi Th6i Lan ld qu6c gia tIAu tiOn tri6n khai c6c m6 hlnh dang nny B-iit rrgrfr, tir viQc sri

dqng c6c ao nu6i ng91 sdu trong dAt ficn de nu6i t6m (tang dQ mpn lOn 2-3 pptli";

c6ch pha vdi nudc 6t > 200 ppt thu ttr c6c rugng muOi; c6c md hinh niy sau d6 nhin

r6ng ra c6c khu vgc nu6i ven bii5n Luqng nu6c bi mdt^Attrong thcri gian nu6i (do bayhoi ho{c rd ri) duqc b6 sung bing nu6c nggt tri c6c gi6ng khoan Uinfr tnric nu6i niy

thuc chdt chi li mQt gi6i pnap tirt *rc nirim han -ch6"nhtng

rui ro vd b€nh dicir(Robertson, 2001 ; Fast vd Menasveta, 2002)

Tai nhirng qu6c gia kh6c nhu M!, Israel, Colombia cilc hQ th6ng nu6i t6i sridung nu6c (recirculation) trang b! hQ th6ng lgc sinh hoc vd co hgc ngny cang dugc sridung rQng rdi hcrn Cfing gi6ng nhu m6 hinh nudi it hoic kh6ng thay nu6c Oih6i Lan,viQc quan llf vi v4n hanh cic m6 hinh nu6i t5i sri dgng nu6c ddi h6i trinh dQ chuyen

m6n rAt cao Th6ng.thulng c6c ch6 phAm sinh hoc nhu probiotics vi c6c lo4i thric 6nc6ng nghiQp dac chiS (cO ti le CN cao) dugc sri dgng trong qui trinh nu6i d6 ntug caoch6t luqng nu6c (Roberston,2001)

Ngh6 nu6i t6m bi6n trong nQi tti3 sri dung nu6c mdn ngarn cfing.li m6t mO hinh

du-o c quan t0m nhi0u trong thdi gian gan dly, dac biet d c6c khu lru" E6t dai cdn c5i c6gi6 tri n6ng nghiQp k6m M6 hinh ndy dang ph6t tri6n 6 My, Israel, Venezuela Gi6 d6t

vi nhAn c6ng 16, khi ndng bi nhi6m bQnh th6p (do nim siu trong d6t Hdn, xa c6c virngnu6i chinh d ven bi6n, kh6ng tlao d6i nu6c vcvi m6i trucrng) ln nhfng lqi th6 ctra md

hinh niy Tuy nhi6n, sg thay ddi.ctra thanh phan h6a hgc vi ctr6t tuqng theo thcri gian

cfing nhu trfr luqng cira nu6c nga{n dang cdn ld nhirng vudmg mic tam thcri SU tIi6u

hpt ho{c hi6n diQn 0 hem lucrng th6p hon mric binh thuong cria mQt s6 ion nhu Ki, Ca2*hodc hdm lugng tr0n mric binh thuong cira mQt s6 ctr6t dac c6 th6 anh huong d6n kh6ndng t6n t4i vd phit tri6n cria t6m nuOi tr,t4c di c6 tiAm ndng nhmg m6 hinh-nu6i t6m

str dpng nudc m{n (lq).ngAm sE chi ph6t tri6n <ltin mQt mr?c tIQ gioi h?n nh6t dinh (CraigBrown, trao d6i tryc tiiSp)

- c6ng trinh nu6i phir hgp cho mQt so aoi tuqng mcri nhu cua, ghg, t6m mfi ni

v6n cdn dang hong giai do4n nghi0n cr?u C6c thir nghiQm nu6i cua, gh'g irorg ao d6t chi

hqn ch6 d T{ {0 n1O1 r6t ttr6p Hao hpt do hiQn tuqng an thit t6n nrrau ltronftncri k} l6t

x6c) dang ld th6ch thric lon cho nhtng nguoi nghiOn criu vO c6ng trinh nu6i-cria cac a5itug4g niy (Clive Keenan, trao <16i tr.uc tiiSp).

4 Ngudn giting

Con gi5ng ati tna nu6i ho{c ngu6l ci th6 b6 me cria nhi6u A6i tuqng girip xic

du-o c khai thdc chri.ytiu tir t1r nhiOn NghA nu6i t6m hirm l6ng vi cua bien ScylkO Vigt

Nam vi mOt sO qudc gia kh6c trong khu v.uc tir trudc ACn nay v6n dga vio ngudn congi6ng khai th6c tt tU nhi6n (Keenan & Blackshaw, 1999) Ei6u niy lim niy sinh nhimg

quan ngai ngiy cang gia tlng vC viQc b6o vQ ngu6n lqr tU nhi0n vi rd rang dE han chC sU

ph6t triOn cira ngh6 nu6i c6c dOi tuqrng niy T4i ViQt Nam, lugng con git5ng cua Scyllaictrai tnac ft tU nhi€n chi c6 th6 d6p ung duqc khoang l\-2To/onhu cAu trong khi k6t qu6cria cic thr? nghiQm san xu6t gi6ng nhdn t4o vdn cdn han chti (Th4ch, ?00?) Cfing tuong

tq nhu vQy, t6m hirm gi6ng ftich thu6c tt 2-10 cm) dugc ngu d0n Uat Ae th6 nu6i trong

l6ng T4i ryOt sO ncyi, d6u hiQu can k19t ngu6,n lqi da trd n€n 16 rimg (John Hambrey, trao

ddilruc ti6p) Do thcri gian ph6t tri6n ctra 6u trung qu6 dei (200-300 ngiy tiry loii) vi

phric t4p, kha narg sdn xuAt con gi6ng nhAn tqo t6m him vin duo c xem ld rAt th6p vi

tl,Org c6lgi nhufn cho d6n thoi ili6m hiQn nay

Qui trinh c6ng nghQ sin xu6t nhnn t4o con giiSng c6c loii t6m bi6n vi t6m cfurgxanh hay mQt s6.lodi t6m cing kh6c.o nu6c nggt dA kh6 6n dinh Da phdn t6m gi6ng thinu6i c6 ngu6n g6c tri circ tr4i sAn xu6t gi6ng nhAn t4o Tuy nhi6n, ngo4i tru mQt s6 it tt6i

tugng nhu t6m chin tring P vannamei,I6m xanh P stylirostris, t6T h? MT B* f.

japonicus dd dugc thuAn h6a vi chgn gi6ng o mQt sd qu6c gia, ngu6n t6m b6 m9 criac5c <t6i tugng kh6c dpa holur todn v,ao k'tr.ai th6c tU nhi6n, il6c biQt ld trudng hqp t6msf

P monodon, aAi tuqng nu6i ph6 bi6n nh6t trdn todn ciu Su 10 thuQc vio ngudn t6m b6

mg khai th6c tir tU nhiOn ve iinfr tr4ng khan hit5m cira ngu6n cung c6p $y <Ie trd thanhmQt trong

"hyg trcr nggi l6n nh6t c[o nghA nu6i t6m sri tr6n toan thC gicri vi cin tro

qu6 trinh thu6n h6a d6i tugng niy (Benzie, 1.997; Ting 2001a) Ciic chuong trinh ,ghie" cuu sir dpng t6m sri bO mg nudi trong di6u kiQn nhnn tao dO san xuAt t6m gi6ngdi5n nay m6i chi thanh c6ng o mric d0 thi nghiQm chri chua dem l4i hiQu qui kinh tC

thUc sU o qui mO san xu6t.16m sri nu6i nhnn t4o thucrng c6 ti lQ thanh thgc th6p, sricsinh sin tt Org cao vi sric s6ng cira con non k6m h<vn so vcvi t6m Uat ttr tg nhi6n

(Benzie, 1997,1998; Browdy, 1998; Huberman, 2000)

Kh6 khAn trong khiu san xu6t gi6ng nhin t4g,, tii sir dgng c6c c6.th6 b6 m9 ,n hi

phi cao trong viQc duy tri 6p lUc chqn lqc de khitin cho c6ng tic thudn h6a, di,1ruyOn

chen gi6ng c6c <t6i tusng nu6i gi6p x6c n6i delg ::" Y6 clng-h?n

3he C.!o ilT 17

moi chi c6 mQt s5 chuong trinh dugc thUc hiQn d vdi qu6c gia cho mQt s6 rdt it c6c d6ituqng tdm nu6i nhu t6m he Nhflt Ban P japonicus, t6m chln trlng P vannamei vi t6m

xanh P stylirostris (Preston vd Clifford ,2002)

SU lQ thuQc it nhiAu vio ty nhi0n trong khiu s6n xu6t con gi6ng cho.nghd nu6i

gi6p x6c d4t ra v6n AC lya chqn dtii tuqng nu6i vd x6c dinh qui m6 phqt tri6n phn hqp

Iho t*g ddi tuqng Vugt l6n trOn nhirng t6c dQng cira thi truong, nghO nu6i gi6p xirc

n6n tfp trung vio nhirng dOi tuqng mi khi ndng sin xudt con gi6l8 nhdn tao cao vi huyttqng'nguon"lgc itO noair tnien qrri tA*r nu6i, n0ng cao nlng su6t cria nhirng ttOi tuq4g

niy."Aif, hucrng tich cgc cria ngh6 nu6i trong c6ng t6c b6o vQ ngubn lql tU nhi6n sE dE

deng biQn tt_r*h tiOu cpc ntiu viQc khai th6c con gi6ng tg nhi0n 0 mtic cIO gay anh hunng

"6n1i6p di6n Cflng tucrng t.o +" vdy, vi0c du nhflp c6c loi,i mcri hay c6c ddng ngoainhflp vdo nu6i t4o ia nhthrg m6i 1o ng4i vO kla $ng hy nhiSm bQnh dich (Tjm Flegel,t.uo AOi tr.uc tii5p) ve nhirn! anh hueng c6 th6 yA m{t ditruy6n l€n nhthrg quan dan n6itlia (Michel1996; Janet Brown, trao d6i tryc ti6p)

5 Thrfrc in

HAu h6t c6c d6i tuqng nu6i c6 gi6 tri kinh te cao thu6c nh6m gi6p x6c d6u thuOc

nh6m An thit (carnivorous) ho{c an tAp (omnivorous) nhrmg thi6n.v6 6n thit, viQc giiiquyi5t thric an ctro chrlng.Ung n mQt [h6 kh[n Cbtup ho{c c6c dOi tuqng thtry san c6

gi+ tri kinh t6 tfrSp nfru moi (Acetes), than m6m thuong dyqc srl dgng lim thric [n v] c6th6 tao ra 6 nhi6m m6i trucrng hopc anh hucrng d6n ngu6n lqi thuj/ san C6c ch6t ainhduong th6t tho6t.tt nsu6; tr,* ai, ra ci @p (l6n tcri 75./.j ;;loi.ira, ii6i cra tt6itugng nu6i c6 thO giy 6 nhi6m cuc bQ m6i trunng nu6i hoac hmlu hai ch6t diy Trong

khi d6, viQc gia tdng- cucrng tIQ khai thhc citc loii thuf sAn c6 kich thu6c nh6 c6 th6 enhhucrng di5n c6c c6 th6 non cira c6c loii c6 giittri kinh ii5 .uo

Thric 6n ctrii Uii5n (dane viOn kh6 hoac 6m) m6i chi phO Uien cho c6c dOi tuqngt6m he vd mQt sO loai t6m nu6c ngqt 6 c6c m6 hlnh nu6i ban th0m canh vd tham canh

Do tinh ctr6t AAc tht, c6c nghi6n cr?u v€ nhu cAu dinh du0ng cria c6c tt6i tuqng nu6ithty san thulng r6t pnyc tap vi k6o dii vi th6 mi kh6 n6ng img dgng c6c kEt quanghiOn cuu vio san xu6t thric 5n c6ng nghiQp phii c6n c6 thcri gian vn tt o*g kh6ngtheo kip sy ph6t triOn nhanh ch6ng crta chc d6i tuqng nu6i mdi ThOm vio d6, viQc sanxuAt thric dn c6ng nglrigp cfing g4p phni kh6 khrn vC nguon protein vi khi n6ng gia

t[ng gi6 thanh san phAm San luqng bQt c6 ctra th6 gi6i hiu nhu kh6ng tAng trong thOi

gian gdn dAy Nim 2001, sin toqng bQt c6 cria hai {u6c gia hang clAuia P; vd Chile

giam h.on I triQu t6n ttri6n cho gi6 bQt c6 c6 chAt luqng t*ng binh tang vgt lQn 450-530

LlSDit6n (Starkey, 2002) Vi th6 mi c6c ngudn protein c6 ngu6n gOJ ttr thlrc vft trencan (dflu ndnh, md, ) phdi du-o c khai th6c nhi6u hon

6 Dich bQnh vi quin lf dich bQnh

Dich bQnh ttang li mQt trong nh&ng mOi de do4 cho sg tdn t4i vi ph6t triiin ctiangh€ nuoi gi6p xic,.cg thc le nghA nu6i t6m BQnh c6 thti do vi khuAn, ,i*r, [i sinhtrung ho{c nhffng U6t tqi vt m6i truong gdy ra Cing vcri thoi gian vd sg gia tdngtrong mric dQ thim canh h6a, s6 lugng dich bQnh ngdy cang nhi6u, giy nhtrrg thiQt h4i lnn

tl4c bi0t khi t6c nhdn g0pr benh le virus ThOm vio d6 viQc di nh{p, trao d6i t6m gi6ng vi

t6m bd m9 gifia c6c quOc gia, virng nu6i girip cho bQnh O .o hQi phet trien, tayian -Cac

loai virus gay bQnh ph6 bi6n 0 t6m he hiQn nay li: YHV (yellow head virus), MBV(monodon baculovirus), TSV (taura syndrome virus), IHHNV (infectious hypodermal

and hematopoietic necrosis virus) WSSV (white spot syndrorne virus) (Lightner &

Redman, 1998; Muroga, 2001; zaruin-Herzberg & Ascencio-valle, 200r) HiQn nay

virus giy bOnh <t6m tr'ing (WSSD {e dugc ph6t hiQn trong hAu hiSt c6c tt6i tuqng giei

xic nudi vi trong cn nhfng san phAm gi6p x6c d6ng lanh (Nunan vd ctv, tsls)- tuynhi6n chi c6 tdm he ld m5n cam d6i vni t6c nhnn gny bQnh ndy Ngodi ra con mQt ;6 lo?i

virus giy xbQnh tr6n t6m he mcri duo c ph6t hiQn nhtmg chi manglinh cgc bQ o mQt vainoi vi cdn cdn phni nghiOn cr?u th€m vi {u nhu G4V (gill associated virus) o Arrstralia(Peter Walker, qSIRO, Australia: trao d6i tr.uc tiiSp) O ViQt Nam c5c lopi bQnh virus

nhu bOnh dtim tring, dAu vang vi MBV khe ph6 bitin ve ld nguy6n nhan chri y6u gfly sstginm nghiOm trgng san luqng t6m nu6i trong nhfing nIm 1993-1994 vi 1998-1999 ctngnhu trong 6 th6ng d6u nAm 2002 (Sd Thriy san Kh6nh Hda, 2002) C6c bQnh virus hiQi

nay ddu c6 th6 duo c chAn dorln d6 dang b6ng phuong ph6p PCR (Lightner & Redman,

I 998 ; Muro ga 2001 ; Alvarez-Borrego & Chavez-Sanchez, 200 I )

Voi hAu h6t cic benh, khi ndng can thiQp khi d6i tugng nu6i d6 nhi6m bQnh ld hanch6 vd thuong.St tOt k6m Nghieq

"* "C Uenfr vi thiS Fp trung nhiAu vdo viQc tim hi6u

co chiS gal b0lh, c6ch thric truycn nhi6m, hy lan 116

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ri cdc biQn ph6p k! thuftphdng chdng t6ng.h9p .HiQn nay c6c huong nghiCn cuu nhim chi5 t4o vaccine phdngbQnh ho6c chgn gi6ng tt6 tao c6c ddng sach bQnh ho4c L*rang bQnh dang dugc quan tflm

thg tdm htrm nhiOu nfr6t ttriS gi6i T6m duo c vfn chuy6n s5ng trong c6c thirng carton vdi

.l

mun cua am

T6m cang xanh, t6m cang nu6c nggt chri y€u tiOu thg tai thi trucmg nQi rlia d c6c

nudc c6 ngh€ nu6i nhfi'ng ttOj tuqng niy ho{c n6u c6 xu6t khAu sang cii nudc lnn cfn thi s6 luong cfing r6t han ch6 Trung bio xic c:iua Artemia chir y5u dugc tiOu thp d c6c

nudc c6 nghd nu6i c6 bi6n ph6t tri6n nhu Nauy, khu vgc nam Uc vd <r noi c6 nghA nu6i

tom he ph6t tri6n manh nhu khu vgc D6ng Nam A, Trung Qutic, khu vuc Nam trrty cia

thi truong ctra tnmg bio x5c Artemia bi6n <tQng r6t lcm, php thuQc vdo ch6t luqng (kichthu6c, ti lQ no, thenh pnan ainn du0ng) vi khi ndng khai th6c tir thi0n nhi6n.1.org

nhfrng nam gdn tIly hiQn tuqng thi6u tnmg beo 1ac Artemia cho nghA san xu6t t6m cigi6ng thgc sq li m6i quan tim cria nguoi nu6i tr6ng thtry sin vi c6c nhi kinh t6 Viecstdpng c6c d6i tugng thay th6 kh6c (chAng han nhu Copepoda) dangtlugc nghiOn criunhAm kh[c phpc kh6 khdn niy.

Gan diy citc v6n aC ch6t lu.qng, vQ sinh an toin thpc phAm cria sin phAm xu6tkhAu dang duoc quan t6m vi quyOt tlfnh gi6 tri cria san phdm C6c san ph6m mang dulugng khang sinh (vi dg nhu Chloramphenicol) bi c6m 6 thi trucrng chnu Au.-Thi

nghiOm cim nhi6m c6c bQnh virus (vi dg nhu bQnh i16m trAng) cho th6y sin phAm tuoiho4c <16ng lanh vfu mang mAm bQnh vi c6 th6 truyCn bQnh cho dan tdm o cic nu6cnhfp nhfrng san phAm niy (vi dU: nu6c thai tt nhd m5y ctr6 Ui6n t6m nhflp khAu ra m6i

trucrng c6 th6 ldm cho c6g dn4 t6m ty nhiOn nhi6m bCnh d Mexico vi Ecuador) Vi thC

c6c qui dinh vn ti0u chuAn.ki6m dich ngdy cang tro n6n ng{t nghdo hcrn MQt s6 nu6c

nhu Uc chi nhap t6m d6 ndu chin vd titin hanh ki6m dich vi xem x6t qui trinh san xu6tcira c6c thric dn c6ng nghiQp c6 thit hodc vo cria gi6p x6c trong thanh phAn Nhimg sanpham du.<v c nl6i theo qui trinh khdng sri dpng miarrg sinh, h6a ctrAt va kh6ng gat anh

h*yrg x6u d6n m6i trudrng <tugc ghi nhen le "ian phA* xanh" (green products) c6c san

pham nny thu<mg dugc ban va giit cao vi c6 khi ndng xam nhQp c6c thi trucmg k*r6

tinh nh6t Tro$B tuong lai, chc chucmg trinh di truyAn chgn gi6ng sc nfrim ACn viQc t4o

ra c6c sin phAm theo nhu cAu d{c biQt cria trng thi trucmg-(mnu s6c, hinh th6i, thenhphdn dinh du0ng, v.v.)

8 Xu hurturg phit tri6n vi cic illnh hutfng nghiOn cltu

Sg ph6t tri6n cira ngh6 nu6i gi6p x6c m4c dr) c6 nhi€u ti6m n6ng cdn php thuQcvdo nhiOu y6u t6 Voi mrlc d0 tham canh ho6 nhu hiQn nay vi viQc tdng cudmg nghiOncriu, dAu tu vdo.di BvA, chqn gi6ng theo huong khang benh;.u d;6" ;6 hq"g ffi;ei

tugrg nu6i truy0n th6ng sE kh6ng giim nhrme sW che,nh lQch vC san lugng giti cac AOi

tuQmg nu6i chtr ytiu vd c6c d6i tuqng nu6i kh6c sE rAt cao Ngay trong nghd nu6i t6m he,mac d.u tflm quan trgng cria da dang sinh hgc ludn dugc.itanh gi6 cao, d6 c6 nhi€u f kiencho ring <Ic tflp trung ngu6n lgc vio gini quyiSt circ viln ac trien t4i v0 c6ng nghQ sanxudt gi6ng vd nudi thucrng phem, quan lf dich bQnh, thric dn mQt c6ch c6 hiQu qu6 thindn c6ng nghiQp nuoi t6m chi n6n dga vio 1 - 2 doi tuQmg nu6i mi th6i Da dqng h6ad6i tuqng nudi vi th6 phg thuQc nhiAu vdo khi ndng tim ki6m c6c dOi tuqng mcyi VcribAt cri d6i tuqng moi ndo, khd ndng giAi quyi5t con gi6ng, sdn xu6t thrtc dn c6ng nghiQpphn hqp ld diOu kiQn ti6n quy6t de c6 th6 ph6t triOn

Tinh 6n cira c6c.di5i tuqng gi6p xkc c6 giittri kinh t6 cao chri y6u la 5n thit Voi mfc dQ gia tdng dAn sO nhu hiQn nay tr0n tod,n cAu, lugmg cirt4p hoac-bQt cA c6 th6 dirng

cho ngh6 nu6i gi6p x6c sE gi6m d6ng kC mQt phAn do nhu cAu thyc phAm cria nguoi

nghdo vd chu y€u do c4nh tranh cira c6c ngdnh chdn nu6i truy€n th6ng (th6ng thudng

, A- '

v6i chi phi sdn xu6t thdp hcm) SU tdng giit cua cilc nguy6n liQu ndy ctrng v6i chi phi caovdo vi€c xAy dpg hC th6ng c6ng trinh nu6i nhim ki6m so6t hiru hiQu b6nh dich vi dim

b6o duoc c6c ti0u chuAn an todn m6i trucrng sE lim tdng giitthirnh sdn phAm, khi6n cho

loi nhu6n cira ngh6 nu6i gi6p x6c giam

tdt canhirng h4n chti tr0n chi c6 th6 dugc gi6i quy6lmql c6ch hiru hi6u th6ng qua

m6t chi0n luoc ph6t tri6n t6ng th0 v6i trong tAm viro c6c vdn dC sau, theo thri tr,r tru ti6n:

- Qqi hoach, phAn virng ph6t tri6n ddi han voi ccy c6u dOi Juqt g nu6i vi mric dQ ph6t

tri6n (di6n tich, sin luqng) phu hqp v6i di6u kiQn kinh tr5 xd hQi, co sd ha tdng phUc

vu sin xuAt vd c5c ngdnh c6 liOn quan Vi0c lua chon dOi tuqng nu6i vd xdy dmg kC

ho4ch nghiCn cuu ph6t tri6n c6ng ngh6 mang tinh chi6n lugc r6t cao Chon lqa dring

v6i kC hoach hqp ly sC gi6m thi6u nhirng rui ro vd gia tdng co hQi thinh c6ng cta

',\

ngne nuor

- Nghi0n cuu ch6 bi6n thirc 6n c6ng nghiQp cho c6c d6i tuqng nu6i ph6 bi6n vn d6i

tuqng nu6i m6i Tim ki6m ngu6n protein thay th6 cho bQt cit vd, su dpng m6t cSchhi6u qud cho c5:c loai thric [n dd c6

- Nghi6n cuu sAn ,u6t con gi6ng nhAn tao oba chc dOi tuqng nu6i dd dugc lga chgn

- Xny dpgcirchQ th6ng qudn l.V ch6t lucrng, dich b6nh cria d6i tugng nu6i, d[c biet lengu6n c6 th€ b6 m9 vd con gi0ng

- Nghi6n cuu xiy drmg c6ng trinh nu6i b6n thim canh hodc th0m canh thich hqp, hiruhi6u trong vi6c ki6m so6t bQnh dfch vd ctrAt tnai; qui trinh nu6i v6i ndng su6t cao

- Nghi6n cuu vd tri6n khai c6c chucrng trinh thd con gi6ng vdo tu nhiOn nhim phgc

hdi vd b6 sung ngudn loi (ddc"bi6t v6i c6c dOi tuqng md ngh6 nu6i dua vdo vi6c thugom con gi6ng hodc c6c c6 th6 b6 me tt tg nhiOn)

Xuc ti6n c6c nghien cuu co bdn nhim phuc vu cdng t5c di truy6n chon gi6ng vdtrii5n khai c5c chucrng trinh di truyAn chon gi6ng

Theo dinh hucrng ph6t tri6n cua BO Thtry s6n, t6ng diQn tich nu6i tr6ng thiry sin

d6n ndm 2010 cira ViQt Nam ld,l,l-1,25 tri0u ha, v6i sdn lugng tt 1,1-1,3 triQu t6n v6itrgng t6m tAp trung vdo c6c d6i tuqng nudi c6 gi6 tri kinh tC cao nhu gi6p xhc, c6 bi6nphpc vr; xu6t khAu Ngodi mQt phAn diQn tich mdt nu6c nQi dia (nu6c nget), diQn tich

.).

lcrn cua ving tri6u (chi€m 39oh tdng diQn tich c6 th0 nu6i tr6ng thtry sin) vd khoing 300

- 4}}.nghin $ mat nu6c quanh c6c d6o cho thAy tiAm n[ng ph6t tri6n ngh6 nu6i gi6pxirc rilt l6n DC c6 d4t duoc muc ti6u ph6t tri6n ndy, chc vdn dO vira nOu tr0n phii dugcxem x6t, cAn nhic k! Trong d6, c6ng t6c Qui hoach vd dinh hucmg ph6t tri6n chi6n lugc

cho timg virng phAi <Iuoc uu tiOn hing dAu.

T6m v6 - Thenus orientalis T6m m0 nid6 - Scyllarides squammosus

Ghe - Porlunus pelagicus (H.Tirng st)T6m cirng nu6c nggt - Cheraxsp (H.T0ng st)

Cua khdng 16 - Paralithodes camtschaticus T6m nu6c nggt - Red claw, Porcambarrus clarkii

Au trlrng Phyllosoma c&a t6m v5 T6m v5 gidng sAn xuat nhdn tgo

Chuong II:

phAn r: cAc DAc DIEM sINH Hec cHU vnu cuA r0u nn

r niNn rrrAr, pHAN LoAr vn pnAN rO

1 Hp ttr6ng phfln lo4i vir cic d6i tuqng nu6i chinh

Theo th6ng k0 cira FAO, tr6n th6 gioi c6 hq*g 343 lodi t6m c6c lo4i c6 grA fi

kinh t6, trong d6 c6 110 loii thuQc h9 t6m he VA hQ th6ng phfin lo4i, t6m he thuQcnganh ch0n khop - Arthropoda,l@ gi6p xhc - Crustacea, bQ muoi chfrn - Decapoda,

b0 phU boi lQi - Natantia, h9 t6m he - Penaeidae Hq tdm he c6 tat ce 4 gi6ng:Penaeus, Metapenaeus, Parapenaeopsis vd Metapenaeopsis Sii luqng loii cria hai

gi6ng Penaeus vd Metapenaeus ld 2i vit 23 Gi6ng Penaeus du-o c chia ra lirn 6 gi6ng

ph1r, bao g6m; Penaeus (Penaeus), Penaeus (Fenneropenaeus), Penaeus (Litopenaeus),Penaeus (Meliceratus), Penaeoo (Marsupenaeus) vQ Penaeus (Farfintepenaeus) Gdn

d1y, trong phin lo4i t6m he c6 xu huong t6ch c6c gr6ng php thuQc gi6ng Penaeus thanhc6c gi6ng chinh; tuy nhi0n c6ch ph0n lo4i niy \h6rg nlran duqc sU ung.h0 ctia gioi khoahgc NhiAu nhi nghi0n criu vi xu6t ban trOn th6 gioi vAn sir dgng h0 th6ng phin lo4i cfl.HiQn tai xu hudng str dpng gi6ng phg ngiy cang tlng trong cic b6o c6o, c6c t4p chi

khoa hgc Mac dn vfy, viQc srl dgng t€n gi6ng ho{c t6n gi6ng php cho c6c loii t6m hethuQc Penaeus dAu duqc ch6p nh{n Trong pham vi gi6o trinh ndy, chring t6i v6n st

dpng tOn gi6ng Penaeus Tuy'nhien, AC tien"cfro viec thim kh6o, ten gi6ng p-nU r5o duq.

tflp hqp vd trich din d bing II t.

Bdng II.I: Chc loiri t6m he dii tluqc nghiGn crfru nudi thinh thgc vi sinh siln trong

ilidu kiQn nhin t4o (Bray vi Lawrence,1992)

l Penaeus aztecus lves Fadantepenaeus aztecus Northem brown shrimp

2 Penaeus brasiliensisLatreille,l8lT Farfantepenaeus brasiliensis

3 Penaeus califtrniensis Holmes Farfantepenaeus californiensis Brown shrirnp

4 Penaeus canaliculatus (Oliver, I 8 I I ) Melicertus canaliculatus Stripped shrirnp

5 Peni,aeus chinensis (Osbeck, 1765) Fenneropenaeus chinensis chinese/Fleshvprawn (P orientalis Kishinouye/

6 Penaeus duorarum Burkenroad

7 Penaeus esculentus (Haswell)

8 Penqeus indicus Milne Edward, 1837

9 Penaeus japonicus Bate, 1888

10 Penaeus kerathurus (Forskal, 1775>

ll Penaeus latisulcatus l

Farfontepenaeus duorarum Pinkshrirnp PenaeuS eSculentUS Brown tiger shrirnp

Fenneropenaeus indicus Indian white prawn

Marsupenaeus japonicus Kuruma shrirnp

Melicertus kerathurus Caramote prawn

Melicertus latisulcatus Blue leg king

; :' /Westem king prawn*

12 Penaeus marginatus Randall

13 Penaeus merguiensis de Man, 1888 Fenneropenaeus merguiensis Bananaprawn

74 Penaeus moiodon Fabricius, I 798 Penaeus monodon Ciant tiger/Black tiger prawn

15 Penaeus notialis Perez Farfant e, 1967 Farfantepenadils notiatis southem pink shrimp '

16 Penaeus paulensis Perez Farfante, 1967 Farfantepenaeus paulensis stgl"ulLnkjhfrne

Eastem king prawnr

Southern white shrirnp Green/Grooved ti ger shriip

Northem white shrirnp Blue shrimp

Pacific white/ Whitelegs pmwn

(*) Theo v! tri cua Uc

Trong s6 50 loii thuQc hai gi6ng Penaeus vd Metapenaeus c6 khoang 20 loiidugc coi le d6i tugng nu6i phtr hgp do chring thich nghi dugc vcri di0u kiQn nu6i nh6t vac6 t6c <IQ tdng trucrng lcm hcrn so voi c6c loii cdn l4i Trong s6 27 loii thuQc gi6ng niy

dI c6 23loii dI dugc nghiOn cr?u nu6i thanh thpc vi sinh san trong cti6u kien nhtn tao(B6ng II.1)

Hi€n nay c6 8 loii t6m he dang du-o c nu6i ph6 bi6n tr€n thiS gicri, trong d6 t6m sri(P monodoz), t6m he Trung Qu6c (P chinensis) vi t6m he chAn trAng (P vannamei) lir

3 i16i tuqng nu6i chinh, c6 sin luqng cao (Bang II.2) Ngoni ra, cdn c6 mQt sii loai kheccfing dugc nu6i & chiu A nhu P penicillatus (t6m du6i d6), P latisulcatus (t6m nilon),

P semisulcalils (t6m rin1, M monocerag M brevicornis vit& chiu M! nhu P setiferus,

P schmitti, P occidentalis, P californie.nsis, P aztecus vd P duorarum

Bdng II.2: Chc A6i trEong nuOi chri y6u tr6n th6 gir6,i (Theo Bailey-Brock, 1992)

Penaeus schmitti Burkenroad, 1936

Penaeus semisulcatus de Haan, 1844

Penaeus setiferus (Linnaeus, I 767)

Penaeus stylirostris Stimpson, 1 874

Penaeus vannamei Boone, 193 I

Litopenaeus schmitti

Penaeus semisulcatus Litopenaeus setiferus Lito p enaeus s ty liro s tri s Litopenaeus vannamei

luqng t6mnu6i th6 eiOi

Cic nrnirc nudi nhi6u

1 Penaeus monodon Fabricius, 1798

Giant tiger prawn / Black tiger prawn

Panama, Columbia, Honduras,Ecuador

Trung Qui5c, Hin Qu5c

Ecuador, Mexico, Panama,

Columbia, HondurasIndonesia, Th6i Lan, TrungQu6c, Philippines, ViQt Nam

An EQ, Indonesia, ViQt Nam

Panama, Columbia, Honduras,Ecuador

NhAt Ban, UcTrung Qui5c, ViQt Nam,Philippines Eii Loan

8

6I

<1

2

2 D{c tti6m hinh thii

a) Ciiu tqo co thi

Ccv thd t6m chia li.rrrr 2 ph6n: dAu nggc (Cephalothorax) vi phAn bung (Abdomen).pfran dAu ngsc c6 14 doi phil phu, Uuo E6*i

(i) I d6i mlt tep c6 cu6ng mit,

(ii) 2 d6i r0u: Anten I (A,) vi Anten 2 (N) A1 ngiin,.d6t mQt lcm vi c6 h6c milt, c6

hai nhanh ngen A.2 c6 nh6nh ngodi bi6n thanh vAy r6u (Antennal scale), nhanhtrong k6o ddi Hai d6i rdu niy dam nhan chirc ndng L*niu gi6c vn gifi thAng bAng

(iii)3 d6i him: d6i him lon, d6i hem nh6 1 vi t16i him nh6 2

(iv)3 <I6i chan hnm (Maxilliped), c6 chric ning gifi mdi, An m6i va h5 trq cho ho4ttlQng boi lQi cria t6m

(v) 5 tl6i chin bo hay chin nggc (pereiopods ho{c walking legs), girip cho t6m bdtr6n mflt il6y Nhi0u loii ba <I6i chin bd 1,2,3 c6 ttdt bdn vd tl6t ng6n c6u t4od4ng kim Ae Uat vi giir m6i; hai d6i 4, 5 kh6ng c6 c6u t4o d4ng kim.

O t6m cai, gita g6c chAn ngpc 4 vi 5 c6 thelycum (co quan sinh dgc ngoii, n<ri nhQn vi git trii tinh tt con dlrc chuy6n sang)

Hinh II.1: Hinh d4ng ngoii cfia t6m he (Theo Bailey-Brock, J,992)

Phdn dAu ngpc dugc b6o vQ bcri gi6p tIAu nggc

(carapace) Tr6n gi6p dAu nggc c6 nhiAu gai, gd, s6ng, rlnh.

Dny ln nhirng dac tti6m lim c6n cf dO phdn loai gi6ng, loei

t6m he Phia tru6c vo gi6p dAu ngpc li chiry dAu (rostrum),

vff khi tg vQ cira t6m Chriy dAu nhgn hinh mfii ki6m, c6 gai

trOn chiry, gai du6i chuy Hinh d4ng chiry, sO luqng gai trOn

vi dudi cria chty ld nhirng <I4c t1i6m ph6n lo4i quan trgng

C6ng thric gai chtry (CR) tluo c trinh biy nhu sau:

(a)b-c

Ilinh II.2: Hinh d4ng rflu I

(Theo Trdn Minh Anh, 1989)

Trong d6: a: s5 gai tr6n chriy nim tr0n phAn gi6p itAu n&uc;

b, c: s6 gai tr6n chtry;

d: s6 gai duoi chiry

Trong hg t6m he, chi c6 circ loai thuQc grdng Penaeus c6 gai ducri chriy (Bang II.3)

Bdng II.3: Hinh d4ng vi c6ng thrfrc gai chfry cria mQt s5 a6i tuqng nu6i

chPenaeus monodon g6c chriy kh6ng cao, chiry hoi cong xu

l/3 chiry cong l6nPenaeus

(3)6-8

3

(3)8-e4-5(3)7-e2-5(2)8-e0

Penneus indicus

Metapenaeus ensis

nh6 cao nhmrg khdng thanh hinh

Phdn bpng (abdomen) c6 7 d6L Nam ddt dAu m5i d6t mang mQt d6i ch0n boi haycon ggi ld chffn bgng (pleopods hay swimming legs) M6i ch0n bpng c6 mQt d6t chungb6n trong, d6t ngoii chia ldm hai nhanh: nhanh trong vi nhAnh ngoii OOt bgng tht 7bi6n thanh telson hqp voi t16i chfrn du6i phin nh6nh tao thanh tlu6i, girip cho t6m

chuy6n dQng lOn xuOng vd bring nhny O t6m dgc,2 nhanh.hong cta d6i chin bpng 1

bi6n thanh petasma vi 2 nhanh trong ctra tt6i chdn bUng 2 Ui+5n ttranfr d6i phq b0 tlUc, ld

c6c bQ phf,n sinh dgc dyc b6n ngoii.

Miu sic co th6 li mQt trong nhihrg dac tti6m A6 nnan bi6t hoflc phdn biQt c6c lod{kh6c nhau T6m sri P monodon miu xanh th6m, c6 khoang tr6"g 0 t46n, khoang vang dchAn nggc (pereiopod), ng6n ch6n c6 miu d6 h6ng ho{c da cam T6m r5n (P semisulcatus)

c6 mdu s6c gdn gi6ng t6m sri nhmgxanh nh4t hon, c5c khoang tf"g it 16 hon T6m th6 (P.merguiensis) miu trdng trong, hoi hdng, kh6p co th6 phtr c6c ch6m nh6 miu xanh, d6, ntu,mep |.chAn miu hdng nh4t ho{c vang Tdm the An EO (P indicus) c6 miu kem di6m c6cchdm nho k*rdp thdn, mep chfur mdu do rO hon P merguiensis Hai loai P merguimsis vd

P indicus i.it gi5ng nhau, d{c biQt tong grai tloqn hflu 6u trtrng vi 6u niOn, tuy nhiOn ni5u

quan s6t ky

"5" c6 thO phan biQt dugc Do sg gr6ng nhau niy nOn chring du-o c x6p chung

vdo mQt nh6m ggi ld nh6m merguiensis-indicus ho{c nh6m Penaeus me.rguiensis Tuong

t.o, hui loii Metapenaeus ensis vit M monoceros cflng c6 hinh thai r6t gi6ng nhau vi dugcx6p chung vio nh6m Metapenaeus ensis

c) Ctic chi fiAu ih fiAn thdn t6m

Hinh II.3: Cic chiiju dii tlo tr6n thfln tdm(Theo Trdn Minh Anh, 1989)

(1) Chiiu ddi chuy diiu RL (rostrum length): Khodng cdch t* mili chuy cho ddn mep sau h6c mdt(2) Chiiu ddi gidp ddu ng;c CL (carapace length): Khodng cdch tit mdp sau hiic miit cftn mdp

sau vd gJdp ddu nglrc 0 mfi fung

Q) ChiAu ddi thdn Ls hoQc BL (body length): Khodng cdch tir mdp sau hiic mdt diin cuiit klsonkhi thdn t6m niim tr€n iludng thdng

G) Chi1u ddi todn thdn L hodc TL (total tength): Khodng cdch t* miii chuy diin cu6t tulson khithdn tdm niim tr€n I iluong thdng

g6c chtrytam gi6c

3 Phin bii

C?" loii thuQc gi6ng Penaeus phan bO tg nhiOn O virqg nhiet ddi vi cQn nhiet doikhip th6 gi6i, tir 40 vi d0 Bac d6n 40 vi d0 Nam Trong 8 d6i tuqng nu6i chinh c6 2loiri

ld: P vannamei vit P stylirostns phin UO O UO DOng ThAi Binh Ducrng S6u loii cdn l4i,

bao gdm P monodon, P japonicus, P chinensis, P merguiensis, P indicus vd M ensisphln b6 vtng An DQ Ducmg - T0y Thei Binh Duong (Bang II.a).

Bdng IL4: Phin b6 cria 8 toii t6m kinh t6 chri y6u

(Holthuis 1980, trich theo Bailey-Brock, 1992)

P chinensis -An DQ Ducrng vd TAy Th6i Binh Ducrng: Trung

Qu6c, H6ng K6ng, Hdn Qu6c

DQ siu: 90-180mBi6n

P japonicus -An D0 Duong vd Tdy Th6i Binh Duong: Tir HOng

Hii, E6ng vd D6ng Nam ch6u Phi d6n Hdn Qu0c,Nhat Ban Phia Nam di5n Indonesia, Bic vd D6ngBic Uc, phia D6ng tliin Fr1i.

-Can Oay du nh4p vdo DOng Dia Trung Hii qua k6nhtldo Suez d6n Nam Th6 NhiKV

-DQ sdu: 0-90 m-D6y: c6t birn-Bi6n

P indicus An D0 Duong vd T6y Th6i Binh Duong: Ddng vd

Ddng Nam chiu Phi d6n Trung Qu5c,Indonesia,New-Guinea, Bdc vi E6ng BIc Uc

DQ sdu: 2-90 mD6y: birn

- I hleu .r nlen: uua song

Tru6ns thdnh: BiiSn

P merguiensis An D0 Duong vd TAy Th6i Binh Duong: Tir vinh Ba

Tu (Persian) dtin Th6i Lan, Hiing Kdng, Philippines,Indonesia, New-Guinea, New-Caledonea, Tdy, Bdc

vi D6ns Uc

DQ siu: 10-45 mD6y:birn

Ctra s6ng vd bir5n

P monodon An DQ Duong vd TAy Th6i Binh Duong: Tfr D6ng

vd D6ng Nam Phi chdu vd Pakistan cl6n Nh|t Bin.

Phia Nam d6n Indonesia vd Bic Australia

Tru6ng thdnh: Bii5n- r.I hleu nlen: uua song

P vannamei D6ng Th6i Binh Duong: Tir Bfc Mexico cl6n Peru DQ s6u: 0-72m

D6y: bin

Tru6ng thdnh: Bii5n

-.,4 I hleu nlen: uua song

M ensis An D0 Duong vd Tdy Th6i Binh Duong: Sri Lanka,

Malaysia tl6n DOng Nam Trung Qu6c, Nhat Ben

Phia Nam d6n Indonesia, New-Guine, TAy, Bic vdD6ns Uc

DQ sAu:18-64 mD6y: birnBi6n vd ctia s6ng

M6i loei c6 virng phhn bd ttia lf kh6c nhau, tiry theo y6u cAu 'rrA AiAu kiQn m6i

truong s5ng cria chfng P chinensz's thich nghi v6i nhiQt dO th6p vi phin b6 nhiAu o Trung Qu6c vi Han Qu6c Phan b6 cira P monodon rQng hcyn vC m6t <tia l1i TOmtrucrng thanh thich s6ng b citc virng nu6c xa bd, c6 d0 trong cao Trong tti6u kiQn m6itrudng nhu vdy chring.c6 t4p tinh.vui minh vio ban ngdy d6 lAn tranh ke tht Tdm th6,P merguienszs phAn UO nfri6u <r gAn cira s6ng nhi6u phtr sa, d0.tlUc cao, ch6t d6y ld birnm6m Vio mia nudc trong, khi dO dpc giim, t6m th6 tet ean rAt d6ng, ldm x6o trQn birndhy, giy dpc m6i truo:ng dO tU vQ (Lucas Ig7g, trich t* Bailey-Brock, 1992)

SU phnn b6 cria t6m he cfing thay <t6i theo giai do4n ph6t tri6n Giai tlo4n 6u trung

vi dAu post-larvacg (< Ps) t6m si5ng tr6i n6i o tdng m{t vi t6ng giiia, tir cu6i giai do4npost-larvae t6m blt itAu chuyi5n sang s5ng dily A P monodon, giai dopn 6u ni6n vdthi6u niOn t6m s6ng o d0 snu 46rg qui 6 m, d6n giai tlo4n sip truong thanh vi truong

thanh tdm c6 xu hucmg di chuy6n ngiy cing xa bd, s6ng n virng triOu vd ngoii khoi D0

siu t6i da bit gap t6m he phtn UO ta tSO m

MQt s6 loii t6m he dugc di nhQp vio c5c qui5c gia chring kh6ng phan b6 tp nhiOn

T6m th6, P merguiersrs dugc dua sang French Polysiana, New Caledonia, Fiji dri nu6i

thtr.nghiQm T6m he chin trilng, P vannamei dugc dua sang nudi 6 Dii Loan, Trung

Qu6c, ViQt Nam, Israel vi Th6i Lan Tdm sf, P monodon du-o c nhflp vio Phip, t6m

he Nhflt BAn du-o c nhfp vdo Italia

O ViQt Nam, t6m sri (P monodon) phnn b6 cht y6u cr ven bi6n c6c tinh miAn

Tryng, tir Quang Binh tt6n Vfing Tiu Tru6c dly o midn Nam 9hi g{p t6m sri o virngbi6n Ki0n Giang Trong nhirng nem g6n diy, <io sg di chuy6n gi6ng ttr mi6n Trung vio

nu6i o midn Nam lim xu6t hiQn t6m sri trong c6c ving nu6c tp nhi6n v6i s6 lugrrg kh6

nhiAu Hai lodi t6m b4c (P merguiensis vit P indicus) ph0n UO O ca 3 mi6n P.merguiensis c6 nhi6u 6 midn Blc vd P indicus c6 nhi6u & miAn Nam T6m tfp trung

nhiAu t4ichc cira s6ng T6m d6t (Metapeneus ensis) thich nghi duo.c v6i nhi0u lo4i chf,t

dby,,khdn6ng ch6ng chiu vcri m6i trucmg lJric nghiQt cao n6n chring phan bO rQng rdi

khdp noi

Hi6u rd duo c d{c tli6m ph6n bO, diAu kiQn m6i truong s6ng ctra c6c loii chring tac6 th€.qui ho4ch, lya chgn ct6i tuqng nudi phir llqp .1ro timg vtrng, timg mta h,ay chondia di6m, mira vg khai thSc gi6ng tU nhiOn O miAn B6c, ncyi c6 nhiQt dQ thAp trongmira d6ng ta c6 thiS xem x6t di nhap dua c6c lodi chiu nhiet dO th6p nhu P chinensis viro

nu6i Cfing c6 thiS nghiOn criu dua c6c lodi c6 ndng su6t cao, kich thu6c lon vdo nu6i

thay cho c6c lodi kich thudc nho, ndng su6t th6p Tuy nhiOn c6c rui ro trong viQc di nhap

(vi dg nhu sg l0y lan bQnh dich cho c6c dOi tuqng nQi dia, c5c dnh huong x6u vO sinh

th6i) phii du-o c xem x6t mQt c6ch nghi0m tric trudc khi thgc hiQn di nhap vd ph6t triOnngh6 nu6i d6i tuqng m6i

II DAC DIEM SINH TRIJONG, PHAT TRIEN vA LQT xAc

1 Cic thoi k) phit tri6n vi vdng dli cfra tdm he

a) Thoi kjt ph6i

Thdi ky ph6i bat dAu tt khi tnmg thp tinh tttin khi trung no Thcri gian ph6t tri6nph6i thay d6i tiry theo lodi vd nhiQt dQ nu6c

@) - nit dAu hinh thdnh mdng truong nudc

(c) - Hinh thdnh xong meng truong nu6c (ming ngoii - Extemal membrane)

(D) - Trtrng thU tinh phAn chia 2 t6 bdo

(E) - PhOi ddu (Ph6i nang - Morula stage)

(F) - DAu giai do4n ph6i Nauplius (Early Nauplius)

(Gr) - PhOi Nauplius binh thudng (- g1: ming ngodi - 92: ph6i - g: ming ph6i)

(Gr) - Ph6i Nauplius di hinh

iHi_ r,,i,e kn6ng th,,r tinh_

[fl:]; I:,,I,f,:*f;Jfor.,*;i:n,*n

(Hr): T6 bio chdt bi vi khuAn Phin huY

Qu6 trinh ph6t tri6n ph6i cira t6m he g6m nhi6u giai do4n Khi tnmg vtra tho6t rakh6i ld sinh dUc c6i, cnat teo tir trimg nhanh ch6ng toa ra t4o n6n sU ch6nh lQch 6p su6t

itr"- ira" gita tnmg vi m6i trudng nu6c N6u nhin qua kinh hiiSn vi tathdy nhtng vdngsang t6a ra xung quanh nOn giai doan ndy dugc ggi li giai do4n hinh thinh vanh ph6ng

x4 Nu6c viro tnmg qua c6c 16 nh6 tr6n ming tnmg vi hinh thd"! ming trucrng nudc

fti *ang trimg At ca"g ldm khit c6c 16, ngdn khdng cho nu6c ti6p tgc vio, qu6 trinhthAm th6u ch6m dut N6u vi mQt nguyOn nhdn nio d6 nu6c vAn ti6p tqc thdm th6u s0

g0y vO trimg Trong sin xu6t, AC mrac phqc hiQn tuqng vd tnmg, nu6c trong bC de rtu-o c

xtr llir voi EDTA (ethylenediamine tetraacetic acid disodium) tir 2 - lO ppm (thucrng li 5

ppm) ye suc khi nhg co chi5 t6c dung cira EDTA trong truong hqp nay u6n chua?ugctim hi6u 16 rdng

Trung t6m phAn cit hoe, todn vi dAu Di5n lAn phdn cit thir hai, c6 sy sap xi5p dac

bi6t c6c tryc phin chia phdi tr6i lQch nhau mQt g6c: 45 - 600, d6i khi d6n 90"

\lltdiyasa, 1942) Sau khoang 10 gid, bat dAu chuyiSn sang giai do4n ph6i Nauplius.

NOu ph6i ph6t tri6n kh6ng binh thucmg, 6u trung Nauplius sC bi di hinh

pOi vOi tnmg kh6ng thg tinh, c6 th6 xhy ra.chc trudng hqp: trung hod,n toin kh6ngph6t tri6n ho4c bi vi khu6n tAn c6ng Trong nhi6u truong hgp, trimg phit tri0n qua c6c

giai dopn ddu nhtmg ph0n cit kh6ng qui luft, tao nOn mgiAam t6 Uao lcrn nh6 kh6ng rlau

vi nlm lQch mQt bOn tnmg

b) ThN kj, du fiilng

Au trung t6m he trii qua nhi0u tan tQt x6c vi bi6n th6i hoan tod.,n vi gdm c6 c6c

giai doan sau:

Giai itoan Nauplius (Nl

Au trung Nauplius ctra da s6 c6c loii t6m he (P monodon, P merguiensis, P

japonicus, P semisulcatus, P vannamei, ) 4e" trdi qua 6 lan lQt x6c vi c6 6 giai do4n

phu con s6 ndy d loii P setiferus chi ld 5 mn Thoi gian o giai doan niy tnaJ, aoi ttry

theo lodi vi nhi6t tlQ nu6c

Loii Nhi6t dO nu6c (oC)

chim Tr0n chac du6i c6 chc gai du6i Cdng thric gai ttu6i ld ttac di6m quan trqng dC

ph6n biQt cilc giai clo4n phg Nauplius Bat dAu tir Nr, m{t bpng xu6t hiqn cac m6u tOi tam6m cira c6c d6i hem 2, hAm 3, chdn hdm 1,2,3 sau ndy Giai do4n N+, Ns, N6 phAn sau

co th6 k6o ddi Cu6i No, hQ tiOu h6a bit diu hopt rtQng.

Giai doan phuNrNz

Nl

N+

NsN6

C6ng thric eai du6i

T6m he chAn tring

-Penaeus vannamei (H Ting st)

lgid 30 phrit(phdn chia ldn2,3l

Nd ra Nauplius 1 (14 gid)

Sau 4 gid (ph6i v!) Sau 5 gid

(Cdc hinh tr€n khOng thd hiCn slr

tudng hng vd kicn thudc cecgiai doAn du tring)

Nauplius 1

- Co thO tron hcrn

-LOng cimg trOn ph6n php trcrn

Dti phan biQt Nauplius 1 vi Nauplius 2 c6 thd dpa vio c6c d{c di6m sau:

Nauplius 2

- Co thiS dni hcrn

- LOng cimg trOn phan phq c6 nhiAu l6ng nh6d4ng l6ng chim

-Gita 2 gai tlu6i chua c6 khuy6t nho - Gi[a hai gai du6i c6 1 htruytit nh6, bit tIAu

- Chi0u dii gai du6i < 1/2 chi6u dii phinchiach4cdudi

then - Chi6u dii gai du6i > ll2 chi€:ndai than

Au trung Nauplius bcri lQi b6ng 3 <l6i phdn phg, vfn dQng theo kiOu zic zic, kh6ng

dlnh huong vi kh6ng liOn tpc Chirng chua dn thirc dn ngodi mi dinh du0ng bdng noln

hoang dp trfr

Hinh II.5: D[c tli6m cic giai ilo4n phg 6u tring Nauplius cria P vannamei

(Kitani 1986, trich theo Bray vd Lawrence 1992)

A-Nr B-Nz C-Nr D-Nc E-Ns F-No

G: m{t b6n Nauplius 1, thanh kich thufc: 0,2 mm

Giai iloan Zoea (Zl

Giai do4n Zoea c6 3 giai do4n phu: Zoeat (Zt), Zoew (Zz) vd Zoea3 (Z) Zt thay

AOi nan vC hinh th6i so v6i Nauplius Co thC Zt k6o dii, chia lim hai phdn: (i) phan dAu

c6 vo gi6p dinh long 16o (ii) PhAn sau gdm 5 dtit nggc vd I phdn bpng chua phdn d6t c6ch4c du6i Zr chua c6 chriy dAu, m6t dd c6 sg phdn chia rO nhmg dinh s6t nhau t4othinh mQt kh6i, chua c6 cu5ng mht Zzc6 chriy dAu, hai mit tep c6 cu6ng mit t6ch r<yi,

phAn bqng c15 chia thanh + ddt 23 c6 phdn dAu vd phdn nggc t6t trgrp tao thanh phdn dAu

nggc vi duoc che phir bdi gi6p dAu ngyc O m$t bsng cu6i phan d6u ngpc xu5t hipnmAm S d6i chAn nguc Phdn bpng c6 7 d6tbao gtim 6 t16t bpng vd 1 ch4c ttu6i, d6t bung

6 dei, c6 mdm chdn du6i

Au trung Zoeaboi lQi nho 2 tt6i riu (d6i 1 phdn tt6t, d6i 2 phin nhtuh kep) vn 3

d6i chin him phAn nh6nh Chring boi lQi liOn tqc c6 dinh hucrng, thing vC phia tru6c

Au trung Zoeabdt ddu dn thric dn ngoii, thric 6n chri y6u li thgc vft n6i vcri hinh thric5n lgc O giai doan niy, 6u trung an mOi liOn tgc, ruQt lu6n ttAy thric 6n vi th6i phAn liOn

tpc t4o thanh du6i ph6n k6o dii phia sau Vi v{y khi nu6i 6u trung Zoea, thric 6n cAndugc cung cap <Iat mQt mQt tlQ thich hgp ddm b6o cho vi6c lgc thric in cira 6u trung

Ngodi hinh thric 5n lgc 6u trung Zoeavdnc6 khi n6ng bit m6i va [n dugc cac dQng vflt

n6i kich thudc nho (Nauplius cira Artemia,luin trung, ), dflc biQt vio cu6i Zz vd Zt ttt6i giai do4n php cria 6u tring Zoea thudng k6o dii khoang 30-42 gid, trung binh 36

KhOng

Kh6ng

Zoea2

C6C6

Kh6ng

Zoea3

C6C6C6

G6m 3 giai ilo4n phu:.Mysisr (Mr), Mysis2 (M2) vd Mysis3 (M3) Chan du6i criaVysis ph6t tri0n dni bing mAu du6i, nhAnh ngoii cria anten Z bat <tAu dpp ttC hinh thanhvAy riu,, co th6 cong gpp Mysis s6ng tr6i n6i, c6 tt[c tinh treo minh trong nu6c, dAuchtic xu6ng dudi Au firng Mysis boi 10i ki6u bung ngugc, vfn ttQng chtr yi5u nhd vio 5

d6i chAn bo

.Mysis Uat mOi chri tlQng, thfc 6n chri yi5u li dQng v4t n6i Tuy nhi6n, chung vin

c6 thO 6n t6o silic, d{c biQt 6 giai tto4n phU Mr vi Mz Thcri gian chuydn giai do4n ctaMysis gAn gi6ng nhu giai doqnZoea

Cic giai do4n php cira Mysis c6 th6 phdn biQt nhanh dpa vdo sU hinh thdnh mdmchdn bgng: (i) Mysis 1: DAu Mr chua c6 mA'm chAn byng, cu6i Mr mAm chin bqng bAtdAu hinh thanh (ii) Mysis 2: MAm ch6n bsng c6 1 tt6t (iii) Mysis 3: MAm chnn bung c6

2 d}t (Hinh II.S)

Giai ttoan Post-larvae (PL)

Hflu 6u trung (Post-larvae) tdm he dd c6 hinh dqng cria loii nhumg slc t6 chuahoin thiQn, nhinh trong anten 2 (A2) chua k6o dii Post-larvae bcri thdng c6 dinh hu6ng

vA phia \rrt6g, boi lQi chi y6u nhd 5 d6i ch0n,bUnS', Post-larvae ctia P monodon co I dulng s6c t6 k6o.ddi .o m{t bpng tit diu riu d6n cu6i telson Lric d6u.duoTg sic td c6

miu d6, sau chuy6n ddn sang den Posl-larvae ho4t dQng nhanh nhgn, bdt m6i chfr dQng,thric 6n chtr ytiu li dQng vdt ndi Tu6i ctra Post-larvae dugc tinh theo ngiy DAu giai

doan, Post-larvae s6ng tr6i n6i, tt PL3 (3 ngny tu6i) ho{c PLs tr0 di chring bit dAu

chuy6n sang s6ng diy Post-larvae chuy6n sang s6ng tl6y hodm toan o PLs-PLro

Thoi gian gita hai lAn lQt x6c tiry thuQc vio nhiQt <tQ nu6c vd tiry loii O nhiet d0

27-2goc, Post-larvae P monodon lQtxhc m6i t,5 ngiy mQt lAn, nhtmg Post-larvae P.merguiensis lQt x6c hang ngdy Khi nhiet dO <270C Post-larvae cria t6m sri lQt x6c m5i

1,5 + 2 ngiy mQt lAn

Trong phAn chia chc giai do4n vong dcri t6m he, tir khoang Ps tro di du-o c gqi li

giai doqn 6u ni6n.

* Ung dqng vdo tO thuqt sdn xuiit giiing nhdn tgo:

Trong sin xu6t con gi6ng t6m he, dga vdo d4c di€m phin b6, phucmg thric s6ng,

thric dn.cria 6u mng ngodi tu nhiOn, cen t4o tli6u kign m6i truong phn hqp nhu: dQ m4ncao vi 6n dinh, giii quy6t thric 6n phir hgp, sgc khi dC tang hdm luqng oxy hda tan vi

t4o di6u ki€n cho 6u trirng s6ng tr6i nOi Viec phnn biQt c6c giai ilo4n 6u trung vd phantloan thdi di6m chuy6n giai do4n cdn cri vdo nhiet dO nudc li r'At quan trgng nhim: (i)

chuAn bi loai thric dn phtr hgrp (vi dU nhu t6o, Artemia, thrlc dn t6ng hgp), dring kich cOcho timg giai do4n; (ii) xny drmg kti ho4ch san xu6t: chuAn bi b.5, chuyiSn Nauplius,

siphon,.thay nu6c, phdng tri benh Th<ri gian chuy6n giaj doan vi mric dQ chuy6n giai

<loqn d6ng lo4t li mQt trong nht,rg cdn crl quan.trgng ae aanfr gi6 tinh tr4ng sric kh6ecria 6u trung, tinh tr4ng m6i truong nudc trong bti uong nu6i, hiQu qud t6c ddng cria c6cgrai ph6p k! thuat

EC phdn biet c6c giai do4n, dac biQt li giai doen phu cira Au mmg tdm he, cfln phni

sri dpng kinh hi6n dga tr6n c6c d{c tli6m hinh thei de trinh biy & trOn Cic giai do4n

chinh (N, Z, M vi PL) c6 thiS <tuqc phin biQt a6 aang bang mit thudng dpa vio hinh

d4ng ngoii, qinh thric boi lQi, tlu6i ph6n hay sU xudt hiQn cria x6c lQt Ngucri c6 kinhnghiQm c6 th6 cdn crl vio mQt s6 d4c di6m nhu 23 c6 dOt Upng gdn ch4c dudi trong vit,

dQ cong co th6 cria Mysis ginm dAn tir Mr d6n Mr

c) Thdi kj,du niAn

O thoi kj,niy, hQ th6ng mang ctra t6m d6 hoin chinh T6m chuy0n sang s6ng d6y,Uit aAu bd bing ch0n vd boi bing chin boi Anten 2vdshc t6 thdn ngdy cing phSt hi6n

Thdi ky niy tuong duong v6i cu6i giai do4n t6m bQt vi diu t6m gi6ng trong sin xu6t,

tric li khoang tir PLs -PLzo.

d) ThN kj, thiifu niAn

T6m bit dAu 6n dinh ti le than Thelycum vi petasma du-ry c hinh thenh nhurgchua hoin chinh, hai nh6nh cria petasma cdn t6ch biet Giai doqn niy tuong duong voi

,',giai tlo4n ucrng gi6ng vi nu6i thit trong s6n xuit CuOi thcri k! thi6u niOn b6t ddu xuit

hiQn sp sinh trucmg kh6ng <16ng dAu giffa 2 gioi tinh (sex dimorphism), con c6i lonnhanh h<rn con d1rc.

e) Thdi kj, sdp tw1ng thdnh

T6m truong thinh vE m4t sinh dpc: Co quan sinh dgc ngoii (petasma vi thelcum)ttd hoan thiQn, t6m dpc Uat AAu c6 tinh tnrrg trong hii tinh, t6m cdi dd tham gia giao vi l6ndAu HiQn tuqng sinh truong kh6ng <tdng d6u giira 2 gioi tinh th6 hien 16 rQt hon trongthoi k) nny

fi fhil ki, trufing thdnh

T6m c6 khi nSng tham gia sinh sin Chfng sdng 0 virng xa bd, noi c6 dQ trongcao vi d0 man 6n ttinh (Trdn Minh Anh, i989)

Bdng II.5: Chc thdi ky trong vdng tldi cria t6m sri

Thi6u ni6n T! lp thdn 6n dinh, ph6t tri6n Diy 4 th6ng Dpc: 11+30 Cria s6ng

Tru6ng thdnh Chin sinh dpc hoan todn DLy

Nd N6i 20 ngity 0,5+Z,Z<*) Khoi -Vtng tri6u

70m

(*) Bdt ddu drsc tfnh theo chiiu ddi gitip ddu nguc (CL)

Ving cii'a s6nq Virng tri6u Virns khol

'r-Hinh II.9: So dd vdng tliri tdm he (Trdn Minh Anh, 1989)

1- Au ni€n 2- Thi6u niOn 3- Sip truong thinh 4- Truong thinh 5- Tnmg

6- Naplius 7- Zoea 8- Mysis 9- Post-larvae

2 D[c di6m sinh tru&ng

O t6m he n6i ri6ng, gi6p x6c n6i chung, sU tang lOn v0 kich thu6c c6 dang bacthang, the hien sg sinh trucmg kh6ng liOn tgc Kich thubc co thO gita hai nn tQt ia fri,

nhu kh6ng tlng ho{c tdng khdng <iling kC vi sE tdng vgt sau m6i mn lQt x6c Trong khi

d6, sp t5ng truong vO *rOi lugmg c6 tinh liOn tgc hcm.

T6m he c6 t6c ilQ tAng truong

tucrng d6i nhanh TOc rtQ tAng

truong tiry thuQc vdo ttnglodi, timg giai do4n ph6t triiSn,

gioi tinh vd di6u kiQn m6itrudrng, dinh du0ng, TOm

non c6 t6c ttQ tdng trucrngnhanh Cang v0 sau t6c ttQ

tdng trucrng cang giam dan

Kich thu6c t6i da kh6c nhau

tiy loii T6m sri c6 kichthu6c lcyn nh6t trong hg t6m

he, con dgc c6 chi6u ddi tointhan (TL) tot 24,7 cm vd con

c6i ld 26,6 cm Tdm th6 P.merguiensis nh6 hcrn, chiAu

dii toan than t6i da rt6 ghi

Kich thu6c tOi Aa cta tdm M

Hinh II.10: So ild bi6u di6n sg sinh tru&ng kh6ng

Ii6n tgc vO t<ich thudc cria giip xic (Chang, lgg2l

nh4n duo.c ld" 17,6 cm & con duc vi 24,3 cmd con c6i

ensrs duc 17,5 cmTL (Trdn Minh Anh, lgsg)

Tir 6u trung di5n dAu thcri k) thi6u ni0n, kh6ng c6 sy khic bi6t vA t6c dQ tAngtrucrng giira tdm dlrc vd t6m c6i Tuy nhi6n, Uit aAu tu cu6i thdi kj, thi6u ni6n, con c6ilcm nhanh hon con dgc

a) Sli tdng trrhng crta du fiilng

Theo Hujinaga-.1942, sg ting truong vA chi6u dni d 6u trung tdm P japonicus thu

sau: Giai do4n Nauplius tdng tr0n du6i l0%ll nn tQt x6c Ldn l0ix6c tir N6 chuy,Sn sung

21 chi6u dii tdng 86o/o, gdn eilp 2lAn, vi d0y cfrng le lan tdng chi6u dni lfn ntr6t tron!

yd.1s itcri cria t6m he Tri 21 chuy6n sangZ2 tdng 25yo, 22 citryi:n sangq3 tdng 13,7%o

(giam U2 so v6i tir 21 sang Zz), Zt chulln sang M1 tdng 13,2o/o Ml chuyiSn sang Mz vi

M2 chuyiSn sang M3 tang >10oh M3 chuyo, r*g pr EnE l2,6yo Trong giai do4n

rost-larvae, su tdng truong vO chiOu dii kh6ng ddu, da s6 < tObttan t0t x6c

Ty le gita chi6u rQng vd chi6u ddi co th€ (R/D) kyn nh6t d giai do4n Nauplius(50%) Ri0nq Nr, R/I) :53,1Yo Ti lQ.niy giim trong.qu6 trinh sinh trunng, sau m6i lanlQt x6c co tho thon hcm Ti le R/D th6p nh6t tir pr dZ;p4 (wD : 1/10), ru" ao t6ng l6n

tY Pl d.5n Pn vi giim jt P,, dtin Prz Tir Prz d6n P21, ty re nn on dion, danh;fu s;chuy€n sang thoi kj,thi6u niOn

Tf 16 chi6u dni gi6p dAu nguc vd chi6u dii toan than (cLlTL): tir pl-r diSn pl-r+:27-28yo, tir PL15 d6n PLzr: 32o/o, tir Pl-21_tro di x6p xi 30%o vd hAu nhu kh6ng thay <t6i

nira, d6nh d6u sy chuy6n sang th<ri k! thitiu ni6n

SU bi6n it6i ctra ti lQ thin o c6c loii t6m he khSc cf,ng c6 khuynh hudng tuong tg

b) Tir iiu niAn ddn fiwhng thdnh

^ ,^

TOm 6u nidn Penaeus merguiensls tdng truong CL I-2 mm/ tuan, tuong ducrng vcri

TL 0,8 mm/ ngdy Trong tudn dAu t6m tdng kfrOi tuqme thin g6p 6 lan Kii vio irong

cria s6ng 6-7 tuAn, t6c d0 tdng.trucrng giam, chi cdn gip 2 lLn/ 2 tudn fhi dat CL =

10mm, t6c d0 tdng truong Ult aAu cO sU kh6c biQt gitia 2 gicn (Trin Minh Anh, 1989).Trong ao nu6i, P indicus dat 18 g, P semisulcatus dpt I lglcon sau 6 thang nu6i

P japonicus vd P latisulcatus d1t 7 glcon sau 6 thang nudi Theo Lobergeiger vi Ttng

2OO3,t6m th6 P merguiensis dqt 16-18 g/con sau 4 thing nu6i

TOm sri P monodon c6 tdc dQ t6ng trucrng nhanh nh6t theo Yamashi, quan hQ

gif,a tudi vn kh6i lugng trung binh cta t6m sri trong tU nhi6n nhu sau:

6 7

Bw (e) 5 10-15 2s 40-5070-80100-120180-250200-250

Theo ktit qui nghiOn criu ctta Nguy6n Trqng Nho vi cQng t6c vi6n (EPi hqcThtry sin), t6m nu6i tai Nam Trung BQ v6i hinh thtic nu6i b6n th0m canh, mOt d0nrOi ZO-f ti con/m2,quan hQ gifra chlAu dii vi thdi gian nu6i dugc the hien nhu sau:

Trong thUc t6 s6n xu6t, PLro c6 chi6u dei than tU 9-11 mm sau 7+10 ngiy ucrngd4t cO l-2 cm (TL), sau l5+20 ngiy tl4t cO 2-3cm, sau 20+25 ngiy tl4t cO 3-5 cm vi sau25+30 ngdy d4t cO 4-6 cm N6u thi nu6i trong ao ttr PLrs sau 1 thang il4t khoang l-2

g/con TOm nu6i 4 thang tt4t kich cO thucrng PhA-, da-s6 le loai 3 (30+40 con/kg), mQt

sO toai 2 (20-3Ocon/kg) O nhfmg ao nu6i diAu kiQn t6t (dO m{n: 10+25 ppt) t6m tdng

truong nhanh c6 th6 thu ho4ch d4t lo4i 3, loai 2 sau'2,5 - 3 thang nu6i

c) fuili tttg crta fim he

T6m he c6 tu6i thg ngin, tu6i thq cria t6m dgc th6p hon t6m cai O t6m the P.merguiensis ngu<ri ta thAy ti lQ dUc/c6i giam dan theo nh6m kich thu6c Ti le dgc/cii

ctra tdm loai 4-5 ldxZ,loqi 3-4 li = 1 vi t6m loq l-2 chi cdn c6 x ll4 (Trdn Minh Anh,tgSg) O t6m sf, trong thdi ky 611niOn vi thii5u ni€n.ti lQ ttUc/c6i h 1/1; trong thoi k)truong thenh (16rg ngiui khoii, sO luqng cii gdp 1,5 hn sO luqllg <tUc' Di6u <16 cho th6y

sy khic biet v0 tu6i ttrg ctra} gi6i Theo Motoh (1981), tu6i thg ctra t6m sri ilpc khoang1,5 ndm vi t6m sir c6i khoang 2ndm.

d) Cdc c6ng thrbc tinh sinh trrhng

Kich thudc cta t6m tai thcvi tti0m t

Lt = L.", (1 - e- k(t'to) )3 Yor: L** : Kich thadc tiii da cila lodi

to : Thdi diAm md kich thudc:0

Ddy ln c6ng thric mi Von Bertalanffy dua ra chung cho dQng vQt, sau niy dugc stidpng cho gi6p xilc m4c dtr tdng tru<rng kich thudc cua gi6p x6c kh6ng 1i0n tgc (TheoTrdn Minh Anh, 1989).

d tOm the P indicus ngu<ri ta c6 th6 tinh toan t6c d0 tdng tru&ng theo c6ng thricndy ducri d4ng CL:

CLt : Cl,r"r(l - .- k(t-to);3 vcri c6c th6ng s5 nhu sau:

EtTc: k: 0,3 to: 0,06 CL*nr: 29,88

Cdi: k : 0,344 to : 0,15 CL,n* : 42,41

Thoi gian gitra2 tan tQt xac

Theo Kurat a (1962) khoing thdi gian gita 2 tan tQt x6c gdm 2 phdn: ph6n co so vi

pnan UO sung PhAn co so kh6ng thay d6i theo kich thu6c thyc ti5 Phen bO sung ti lQ voithC tich co thO t6m

C6ng thric : D: do + k CL3

do : Thoi gian phdn ccv sd bing hAng sO AAc tnmg cho loii

k : Hing s6, bi6u thi th6 tich y6u cAu b6 sung

CL : Chi6u dni gi6p dAu ngsc (mm)Hiroshi Motoh (1981) tinh cho P monodon:

D:8,33 + 4,55 CL3 (r:0,461, P < 0,001, df : 190)

Nhung 6ng cfing tinh theo m6i quan hQ cho hQ s6 tucrng quan cao hcrn:

D = 3,10 + 0,66 CL3 (r:0,727, P < 0,001, df : 190)

Tucrng quan gifra kich thu6c tru6c lQt x5c vi sau lQt x5c

Kurata (1969) dlra vio c6c si5 fiQu ting truong x6c dinh m6i quan hQ niy ld duong th5ng: ,

Ln+l:a*bLn

Y6i Lnvd Loal: ChiAu ddi trudc vd sau l\t xdc a, b: Cdc hdng sii

Hiroshi Motoh (1981) x5c dinh tr6n P monodon:

L-+r :0,09 + 1,01 L (r:0,997, p < 0,001, dcrn vi: mm)Tuong quan giiia chi6u dii co th6 (TL hoac BL) vi chiOu ddi girlp dAu nggc (CL)ctra t6m st P monodon (Trich theo Trdn Minh Anh, 1959)

+Thdi k] t6m bQt vi 6u niOn:

TL: -2,9 + 6,21CL (r:0,935)

+Thdi k! thi0u niOn <li5n tru&ng thdnh:

Dyc: BL : I1,8 + 3,31 CL (r : 0,983)CAr BL: 22,8 + 3,00 CL (r : 0,990)

Loiri Gicri tinh Tuons quan tins tru0ne 56 miu

P merguiensis

Duc

c6i

W: 173x10-6 TLr'r' W:319x10-8 Tl-3'res

6492

Eucc6i

W: 1001x10-8 TL 2'e63

W :497x10-8 TL 3'113

t432t727Duc

cai

logW:-4,04+2,56logTl loeW:_4.49+2.09 loeTl.

t52 t70

P monodon

Duccai

logW:-2,73+2,71logTl loeW:-2,64+2,65loeTl-

383383

Tucrng quan gifia chi6u dii vi kh6i luqng

Bdng II.6: Tuong quan ting tru&ng 0 t6m he (Trich theo Trin Minh Anh, 1959)

3 Sg lQt xic

a) Co chii sinh hgc crta quti trinh lQt xtdc

D6 sinh trucrng dugc, t6m cfing nhu t6t ch cic ttQng vQt ch0n khorp kh6c ti6n hdnhlQt x5c SU lQt x6c chi le ktSt qua cu6i ctrng cira m6t qu6 trinh phric t4p, trdi qua nhiAugiai do4n, dugc chu6n bi tu nhi6u ngiy ho{c nhiAu tuAn tru6c tI6 Qu6 trinh chuAn bi

di6n ra 6 tit ch c6c m6 c6 liOn quan thOng qua c6c hoqt <tQng nhu: (i) huy dQng ngu6nlipid dp trii d gan, tpy ho{c o tuy6n ruQt gita (midgut gland) o gi6p x6c bflc th6p, (ii) sp

phin bdo gia t[ng va (iii) c6c ARN th6ng tin duoc t4o thanh vi ti6p theo ld qu6 trinhsinh t6ng hgrp cfc protein mcri Trong thcri gian niy tr4ng thai cira t6m cfing thay d6i

Qu6 trinh phric tap ddi h6i c6 sU ph6i hqp ch?t ch€ gifia chc co quan c6 liOn quan

vd cdn c6 sg tham gia cria c6c hormone Ban dAu c6c m6i liOn kiit gitia bi6u bi vi lop vocimg bOn nggni duqc lim" l6ng dO girip cho t6m c6 thO tho6t kh6i l6p v6 cfi Sau d6,

nu6c dugc h6p thp qua bi6u bi, mang, ruQt ldm t[ng thd tich m6u, khiOn cho lorp vo moicon dang m6m d6o cdng l0n vi kich thudc cria t6m vi thi5 gia tdng Ti6p theo li sp tich

t9 chAt kho6ng vi protein, nu6c ddn d6n duqc thay bdng l6p m6, v6 moi cimg dAn l6n

Chu k) lQt x5c duo c c6c thc giit ph6n chia thanh nhi6u giai do4n ttry theo ting loii, m6i giai aoa" c6 thb c6 nhieu-giai do4n phu $t phric tapIDC Ocrn gian, chfng ta

xemx6t sg phAn chia chung cho t6t ch gShp x6c KO tir Hn lQt x6c tru6c diSn Hn lQt xac

kC ti6p, chu k! lQt x6c du-o c phin chia thdnh 4 giai do4n: (i) giai doan sau lQt x5c molt), (ii) giai do4n gifra l6t x6c (Inter-molt), (iii) giai do4n tru6c lQt x6c (Pre-molt ho{c

(Post-Proecdysis) vd (iv) giai do4n lQt x6c (Molting stage) (Trich theo Chang, 1992)

- Giai ilogn sau bt xdc (Post-molt)

Li giai doan kC ti6p ngay sau khi t6m lQt x6c- D0y ld khoang thcri gian tt khi nu6c

dugc hdp thg vio m6u qua bi6u bi, mang, ruQt tl6 lim tdng th6 tich m6u, cdng lop v6

mtvi cdn mOm d6o cho d6n khi l6p vo moi tI6 cimg lai Giai doqn niy c6 thO k6o ddi viingny d6i vcri t6m l6n ho{c vii gid OOi voi t6m cdn nh6

- Giai doqn gifia lAt xdc (Inter-molt)

E0y H grai do4n dai nh6t theo sp ph0n chia niy Su6t grai <to4n ndy v6 <ti cimg l4i

nhd sg tich tu ch6t khoang vi protein V6 dny vd dAy dtr ci 3 ph6n nhu hinh vE (Hinh II.1 1).

- Giai doqn trudc l1t xdc (Pre-molt)

Lcrp m9 simg ngoii m6i (1') hinh thanh vio dAu giai dopn,tru6c lQt x6c (earlypremolt) CuOi giai do4n tru6c lQt xic (late pre-molt) hinh thanh ti6p lop giffa m6 simg

moi (2'.) Lric ndy lcrp v6 cfi dd bong ra kh6i 16p bi6u bi d phia dudi lim cho vo tdm c6

miu tring dpc Eny li mQt trong nhirng dAu hi6u d6 nhfn bii5t sg lQt xic sip xiy ra O

giai doan niy ndng lugmg dugc di6u dQng tir San tpy, mQt phAn v6 cfl c0ng dugc h6p thplai, hirm lugng hormone lQt xic trong m6u tdng cao vd sau d6 giflm clQt ngQt ngay tru6c

klri sg l6t x6c xtry ra

- Giai dogn l|t xdc (Molting stage)

Chi k6o ddi vii phrit, bdt dAu tt khi l6p v6 cfi tilchran m{t hmg noi titip gi6p gifia

, -l

vo dAu nguc vi vo phdn bpng vi kOt thric khi t6m thoSt hdn l6p vo cfi

Trong qu6 trinh lQt x6c cria gi6p xhc, chc di6n bii5n kh6ng binh thuong ctra giai

doan tru6c s€ gAy kh6 khAn cho c6c giai do4n tC tiep Lorp mO duoi lop vo mdi bat tuQc

phii dugc ph6t tri6n vi n6 dE dugc chuAn bi dAV dri v6 chAt, n6u t6m kh6ng 10t x6c dugc

Ddu giai doqn trudc l\t xdc

Ilinh II.1l: Sq phfln chia chu ky tQt xic chung cho gi6p xhc (Chang, 1992)

L-LCIp mO s*ng ngodi hay ldp cuticun ngodi (Epiculticle)

2-Lop m6 s*ng gi{ia hay lop cuticun gitra (Exoculticle)

3-Lop m9 simg tyong ho(c l6p cuticun trong (Endoculticle)

4-Lop tii bdo bi€u bi (Epidermal cells)

Giai doqn sau lQt xdc

Giai tlo4n lQt xic

CuiSi giai doqn trudc l\t xdc

T6c ttQng ctra c6c y6u tO vQt llf l6n qu6 trinh lQt xic c6 th6 gAy nguy hi6m cho t6m.Khi lQt x6c t6m p.h6ng thich ra m6i truong nu6c ch6t dich lQt x6c bao g6m c6c axit amin,

enzpe vi mQt s6 chit hiru co (c6 khd nlng ty phan !liy) tt l6p vo cfi Dich lQt x6c cfing

h ch6t kich thich m4nh thu hrit c5c d$ng v6t kh6c t6n cOng ttng khi t6m cdn yi5u; khInrng v4n d0ng, tu vc triinh ke tht cdn han chti oay h giai do4n nguy hit5m cho t6m.Theo m6t c6ch phln chia kh6c cta Drach 1939 (trich theo Trin Minh Anh, 1g8g),

chu kj, lQt x6c gom 5 giai do4n: A -Ngay sau lQt x6c, b-sau lQt x6c, c-Giira lQt x6c, Tru6c l6t x6c, E-LQt x5c Theo sg phAn chia ndy thi giai do4n D (tru6c lQt x5c) le deinfr6t fra6i giai do4n lpi ttugc phin lim nhi6u giai doan phg, cdn cutr6n c6c bii5n O6i vC

D-hinh th6i rAt chi ti6t vi phric t4p

b) SV iliiu fi& hormone trong quti trinh lQt xtic

Hormone lQt x6c (Ecdysteroids):

C6c k6t quA nghiOn cr?u cho th6y c6 sg tuong d6ng trong su diOu titit nQi titit d c6cdQng v4t chin khcrp TrOn co sd d6, nhting ktit qui nghi0n cr?uvO nQi ti6t trong qu6 trinhlQt xic trOn dQng vft chan khop ctng dring cho cdc dQng vft thuQc lop gi6p x6c

Hormone l6t x6c <r ttQng vft chnn khorp <luqc nghi€n ctu dAu ti0n o c6n tr:trng (bu6m

dg*), sau duqc nghiOn criu 6 t6m hirm vi.nhi6u gihp x6c kh6c M4c dir sp nghiOn cr?u

vO nQi tii5t trOn t6m he cdn it nh,ng thpc t6 <h chimg minh cic k6t qui nghiOn cuu trentdm hr)m, cua Cancer antennarius, Pachygrapsus crassipe vd cilc loii gi6p x6c thu$c bQ

phg bd (Reptantia) dAu c6 thO 6p dung cho t6m he

Hormone lQt x6c d chin.hop .O g6c steroid nOn ggi li Ecdysteroids Hormone lQt

x6c.(edysteroids) trong m6u t6n tai 6 2 dqng: (i) Dang chua ho4t h6a dugc sinh ra tt

tuy6n lQt x6c ggi ln ecdysone (ii) Ecdysone duoc ph6ng thich vio m6u, trdi qua qu6trinh hydroxyl h6a trd thanh d4ng ho4t <10ng sinh lf tham gia tryc tiiSp vio qu6 trinh l6tx6c ggi le 20-HE (20-OH-ecdysone ho4c 20 hydroxy ecdysone)

Tru6c d0y, hormone lQt x6c cv c6c loii gi6p x6c kh6c nhau dugc ggi vcyi nhi6u t0n

kh6c nhau: ponasterone A (25-deoxy-20HE); inokosterone (25-deoxy-20, dihydroxyecdysone); makisteron e A (24-methyl-20HE); 20, 26-dihydroxyecdisone; 2-deoxyecdysone Trong nhidu tii liQu, hormone lQt x6c cdn dugc gqi U6rrg c6c t6n kh6c

26-nhu: Ecdyson cdn goi ld cr-ecdysone., 20HE cdn ggi: B-ecdysone, crustecdyson,ecdysterone; Ecdysteroids cdn goi: ecdysones GAn dly d6 thdng ntr6t Otrng c6c thuft ngir: Ecdyson, 20HE, vi gg-i chung Edysteroids d6 chi tdt cac6c dqng hormlne lQt x6cc6 c6u trfic polyhydroxyl steroid (G6c steroid vi nhi6u nh6m hydroxyf (Chang, 1gg2)

Co quan Y (.Y-organ) li tuy6n nQi titit san sinh ra hormone lQt x6c (Ecdysteroids)non cdn ggi li tuyiSn l6t x6c (molting gland) 6 cua, co quan Y ld I tctroi oic, ot6m htm

vi c6c loii t6m kh6c co quan Y c6 d4ng brii sqi Vi tri cta co quan Y o phAn tru6c

khoang *ang;NhiAu nghi€q crlu.x6c ttinh san pham nQi tii5t cta coquan Y li ecdysone

Co quan Y tdng hgp vi <tidu titit ecdysone tir cholesterol Ecdysorrl duqc ph6ng thichvdo m6u trii qua qu6 trinh hydroxyl h6a thinh 20-HE (20 Hydroxy Ecdysone) li ch6ttrao d6i hoat h6a, tr.uc ti6p t6c rlQng vio qu6 trinh lQt x6c

Cholesterol Hydroxyl h6a

Co quan Y -+ Ecdysone :: :: : ) 20-HE

-* L6t x6c

(M6u)