Tgp chi Khoa hoc - Cong nghe Thuy sdn
KET QUA NGHIEN CLfU DAO TAO SAU DAI HOC
NGHIEN C l f u MOT SO DAC D I E M SEMH HOC SINH SAN VA THU* NGHIEM SAN XUAT GIONG NHAN TAO CUA D O N G
{Somanniathelphusa sisnensis, Bott 1970)
STUDY ON SOME REPRODUCTIVE BIOLOGICAL CHARACTERISTICS AND ARTIFICIALLY EXPERIMENTAL REPRODUCTION OF RICE CRAB
(Somanniathelphusa sisnensis, Bott 1970>
Nguyen Hdng Dvc', Thdi Thanh Binh^
Ngaynhanbai 10/10/2012; Ngay phan bi|n thong qua 27/11/2012, Ngay duyetdang: 15/5/2013
T6M TAT
Cua dong (Somanniathelphusa sisnensis, Bott 1970) Id mpt trong nhieng lodi gidp xdc cd gid tri kinh li vd phdn bd rpng lgi Vi4t Nam Nghien cieu ndy dupc thuc hi^n nhdm tim hiiu mot sd ddc diim sinh hoc sinh sdn vd buac ddu thie nghiim sinh sdn cua dong. Kit qud nghien cuu cho thdy miia vu sinh sdn cua cua ddng Id tit thdng 4 - 10, tdp trung tie thdng 5 - 7 Cua dong cd the thdnh ihuc sinh difc vd tham gia sinh sdn ldn ddu khi dgt khdi luang thdn tie 7,8 - 12,1 g vd chiiu rgng mai 2,8 - 3,0 cm Qud tiinh giao vicua cua dong keo ddi 30 phtit, stic sinh sdn luyel ddi Id 24 ±9 trieng/g cua m?, siec sinh sdn tuang doi Id 199 ±93 Irung/cua m^. Thd^ gian phdi trien phdi keo ddi 12 -15 ngdy Khdng co su khdc biet ve sinh tntang cua cua con tie nguon cua mf nuoi vo vd cua m^ thdnh thuc ngodi tu nhien Kel qud nghien citu cho thdy c6 thi tiin hdnh sinh sdn nhdn ttfo cua dong de chu dgng ve nguon giong phuc vu nhu cdu nudi thuang phdm
Tit khoa: Cua dong, Somaniathelphusca sisensis, nudi vo, cua con ABSTRACT
Rice crab (Somanniathelphusa sisnensis, Bott 1970) is one of a highly valuable and wide - distiibuted c.
species in Vietnam. This study was conducted in order lo learn about some reproductive biological characteristics and artificial reproduction of this species under laboratory conditions The results showed that spawning season of rice crab ranged fivm April to October, concentrating from May to July Rice crab could mature and participate in reproductive activity at the first lime when reaching Ihe size of 7.8 - 12.1 g in body weight and 2.8 - 3.0 cm in carapace length. The mating ativity of rice crab commonly took place for 30 minutes, absolute fecundity was 24 ± 9 eggs per female weight, and relative fecundity was 199 ± 93 eggs per female crab. The embryonic duration lasted between 12 and 15 days. There was no significant difference recorded about growth rate and survival rate of juvenile crabs between natural and artificial matured crab sources. The results fivm this study showed that It ts possible to reproduce nee crab artificially in order lo meet the demand of growing - out culture.
Keywords. Rice crab, Somaniathelphusca sisensis. artificial matured, juvenile crabs
1. OJ?IT V A N Bt nguin igi cua ding . Do do, tren mdt so dia phuang Cua ding Id iodi gidp x i e phdn h i r i n g rdi trong nhu Dong Thip, Bac Ninh .. ngudi ddn da tien hdnh eie thiy vgc nude nggt d nude la (Ding Ngoc nudi cua ding, ket qua eho Ihly nang suit cao. gia Thanh v i H i Thanh Hdi. 2001). Trong vai nam g i n ea on djnh v i dugc thi trudng ua ehuing (Le Thj ddy do vi^c khai thdc cgn kigt v i su dyng hoa chat Binh. 2011). Viec dau tu v i cham sde d i dang, thirc trong ndng nghiip dd ldm suy gidm nghiim trgng an don gidn d§ kiem nen nhilu hd nuoi da thu duge
' Nguyin Hing Due: Ldp Cao hgc Nu6i tr6ng thiiy san 2009 - Tnj'dng Dgi hpe Nha Trang ' TS. Thdi Thanh Binh' Tnrdng Cao ding Thiiy san - Bic Nmh
TRLfONG OAi HOC NHA TRANG • 95
Tgp chi Khoa hoc - Cong nghe Thuy sdn S6 2/20JI \\\\\
Igi nhudn kha eao h> nghi nudi cua ding thuong phim. Tuy nhien. nguin eua giong hign nay van ehii yeu dya v i o khai thde tu t r nhidn. Trong khi i d , qud trinh khai thdc va van ehuyin g i p nhilu khd khan din den ty Ig hao hut eao, ty le song trong qud Irinh nudi thip, eua khdng Ihich irng tot vdi diiu kign nuoi nhdn tgo vd viic khai thde cua giing phu thupe chat che vdo v i n de thdi liet vd miia vy (Tran Nguyin Duy Khoa vd etv., 2011).
Neu nhu ed r i t nhieu ede nghien euu ve smh san nhin tgo cua bien dugc thgc hign tren the gidi eung nhu d Vigt Nam (Nguyen Trgng Nho va etv., 2006; Nguyin Co Thgch. 2007) Ihi eic nghi&n euu v i eua ding edn r i t hgn ehe vd chi dung igi d viec nghien ciru dgc diim sinh hgc. phdn b i vd phan logi (Thii Thanh Duang, 2003; Dgng Nggc Thanh va etv., 1979). Nghidn euu sinh sdn nhan tgo eua dong mdi chi dugc thgc hien trin loai Somanniathelphusca germaini (Trin Nguyen Duy Khoa va etv., 2011 vd Ld Thj Binh, 2011) trong khi d i ehua cd nghidn eiru ndo trdn iodi Somaniathelphusca sisensis dugc thgc hiin. Vi vgy nghien cuu mgt s i dac diem sinh hge sinh sin v i Ihu nghigm smh san nhan Igo cua ding Id co sd quan trgng cho vige xdy dgng vd hoan thign quy Irinh smh san nhdn tgo cua ding ddp irng nhu c l u nudi Ihuong phim tgi nhiiu dia phuang tren e i nude.
IL VAT Lieu VA PHU'aNG P H A P NGHliN CtfU Nghidn ciru dugc thuc hiin tgi Trgi thuc nghigm Nudi tring Thuy san Nude nggt, Trudng Cao ding Thiiy sin, Bae Ninh tir thing 5/2010 den thing 3/2011.
1. Nghiin cu'u mot so dgc diem sinh hgc sinh san cCia cua dong
Cie mlu eua dong dugc thu tir ngoii tu nhien, sau dd duge phdn nhdm kieh thude d l nghien ciru eic ddc diim sinh hgc sinh san. Nhdm 1 bao gom cua c i kich thudc 2,8 - 3,0 em, khii lugng tmng binh 10,04 g/eon; nhdm 2 ed kieh thudc 3,1 -3.5 em, khii lugng trung binh 12,54 g/eon; nhdm 3 cd kieh thudc trin 3,6 em, khoi lugng tmng binh 15.37 g/eon.
Kich thudc thdnh thye sinh dye Iln dau dugc xdc djnh l i nhdm cua eo kich thude nhi nhit md trong dd 50% s i cd t h i c i tuyin smh dye d giai doan III v i IV. Trong nghien cuu niy. phuang phdp nghien cuu cdc dgc diem sinh hgc sinh san dua trin mgt s i t i l li$u thdng dung, hign hanh eiia Hodng Due Dgt (2003), Bauer (2004), Churchill (2003) v i Islam (2010).
D i xdc djnh miia vy sinh sdn ciia cua dong, tiin hdnh Ihu mlu ngoai tg nhien vd gidi phau d i quan
sg phat trien luyln sinh dye ciia cua dgc, eua cai va ' xde djnh ty le thdnh thye tir thdng 5 d i n thdng i ; i De quan s i t dugc q u i trinh giao vy cua eua d&ng, i cua due vd cua c i i thanh thye dugc ghip chung I trong chgu nhua cd the tieh 20 L (theo Bauer, 2004) j Tien hdnh quan sdt, tfnh todn thdi gian, quan sat vS ! m i la boat dgng giao vy eua eua dong. Qud trinh i phat trien phdi ciia eua ding dugc tinh tir khi trtrng ! dugc thu linh tdi khi phii nd. Sau khi eua dd trtmg, lly 100 tnJng da thy linh d l quan sdt cdc gial do^fi phdt tnen phoi dudi kinh hien vi
2. Thir nghiem sinh sdn cua dong 2 . 1 Nuoi v6 cua bd mg;
Cua b i mg dgt kfch thudc thinh Ihyc sinh dye duge thu ngodi tg nhiin, sau dd, tiin hinh nufii vo trong ao cd dign tich tCr 500m^, d i siu mgc niniic 0,8 - 1.2m. Trudc khi tha nudi. c i n v i sinh, khir triing ao bang v i i bgt vdi iugng 10 - 15kg/100 m', phai ao 5 - 7 ngdy. Xung quanh bd ao dugc rSo bing ddng tre vd t i m fi-bro xi mdng d l ngan khfing cho eua bd ra ngodi. D i hgn ehe hign tugng an nhau khi lot xde, lien hdnh bo sung eie ong nhi;a PVC c i t nhi (2 - 3 ing/m^) xuong diy ao lim noi tru I n cho cua. Mgt d i nuii 5 con/m^, H l i dgc: cai i i 2 . 1. Cua dugc cho dn thue an cd tgp kit hyp vdi thde an edng nghiip vo'i ty ie iln lugt i i 70% vi 30% Cua duac cho an vdi ty le 7 -10% khii lui^ng than ehia lam 2 lln/ngdy, iugng buii sing bing 1/3 tong iugng thirc dn.
2.2. Theo doi edc y^u to mdi trwcmg:
Cdc yeu to mdi trudng nhu: nhigt d i , oxy hoa lan. pH dugc do 2 lln/ngay (8 gid sdng vd 2 giir ehieu) bing nhigt k i . mdy do oxy vd test pH. HSm lugng NH^ va NO^ duge xae dinh 2 lln/tuln bing bO test nhanh SERA cCia Dire.
2.3. Xac dinh m0t s6 chi tieu sinh sin:
D i xdc djnh mgt so chi tidu sinh sdn ciia cua, djnh ky 15 ngdy kiem tra cua b i mg, bit rieng nhiJng con cua edi dm InJng, dm con lien hdnh quan sSt Tien hdnh thu ngau nhidn 30 eua cii d l xdc djnh s6 eua dm trirng v i dm com. Ndng suit eua eon duffc xie djnh bang cich d i m s i iugng cua con c i trong yem ciia 30 eua mg thu ngau nhien.
2.4. (fang nuoi cua con:
Cua eon thu tir eua mg tg nhidn vd tir eua me nuii vd dugc uong nuii riing trong chdu 20 L, mi,rc nude trong chdu 5 - lOem, g i i the l i bdo tdy, ludi eudc t i i miu. Mdt d i uang 10 con/L. Cua eon duo'c cho an thde dn chlnh Id Idng d i tn>ng gd kit tipp vdi dgng vat phii du. Ddy Id cde logi thdc dn thuftng dimg trong uang nuii au triing eua biln (Hoing Dire Dgt 1995; Le Thj Binh, 2011). Thudng xuySn
Tgp chi Khoa hoc - Cong nghe Thtiy sdn So 2/2013
quan sdt hogt ddng bit m i l cda cua de ffieu ehinhIhirc an va vg sinh thay nude 2 ngdy/lan. Djnh k^
7 - 1 0 ngdy/lln. ben hinh kilm tra ngau nhien 30 cua con de xac djnh l i c dp sinh taring giO-a edc nghiim thirc.
3. Phuvng phdp thu thap vd xi> ly so lieu Nang suit cua con:
S i eua eon dem duge (eon)
III. KtJ QUA NGHIEN CCTU
1. Ode diem sinh hoc sinh san cua cua dong 1.1. Mua Vil sinh san
K i t qua giai phlu cho Ihay luyen sinh dgc (TSD) ciia cua ding bat d i u phit trien manh tir cuii thdng 3, miia sinh sdn l i tir thing 4 d i n cuoi Ihdng 10.
Cua de nhieu nhit vdo thdng 6 den thing 7.
Ndng suat cua con = -
Khil lugng cd the cdi (g) Tyle thanh thue (%):
Tli' Ig thanh thuc (%) So cua cdi finfi tnrng, 6m con(con) S6 cua cii kiem tra (con) Tic dd sinh trudng tmng binh ngdy DWG (g/ngdy):
™ . , ^ W2 - WI DWG=
t 2 - t 1
T i c do sinh trudng dgc tarng SGR^ (%/ngay):
^ „ „ lnW2 - InWI
SGR„ = xlOO
^ 12-11 Vdi: W I : Khii lugng cua tgt thdi diem t l (g)
W2: Khoi lugng cua tgi thdi diem 12 (g) 11: Thdi gian do i l n trudc (ngdy) 12: Thdi gian do iln sau (ngdy) 4. Phiro-ng phdp xip Vj s i li^u:
Cde ket qud ve dugc xu ly theo phep phdn tich phuong sai mgt nhan l i one-way ANOVA tren phin mIm SPSS 16.0 vd phin m i m Microsoft Excel 2003. s i lieu dugc Irinh biy dudi dgng Tmng binh
± Sai so ehuin (SE).
VM gta (ItloO Hinh I.Sy phat triln tuyen sinh due cua cua ngoii ti^nhiSn
tu thing 5 den thang 12
Kit q u i kiem tra cdc mlu cua thu tir tg nhien trong cde thdng Ihi nghiem (thing 5 - thdng 12) chg thay: 100% s i cua kiem tra thdnh Ihyc sinh dgc vdo cdc thdng 5 - 8, ty le ndy bat d i u giam d cic thing 9 -12 vdl ty Ig thdnh thue luang ung l i 90, 83, 63 v i 21%. Cie quan sdt ngodi hign trudng tgi dja diem nghien euu, tir nhirng cinh dong quanh khu vgc nghien eiru va Iheo quan s i t eua ngudi ddn b i t eua nhiiu ndm qua eho thay eua con thudng xult hiin r0 trong c i c mgng lua vd ao dim Irong khoing thdi gian thing 6 - thing 8.
1.2. St/phit trien tuyin sinh due
Tuyen sinh dye cua ding trii qua 4 giai dogn phdt triin d i i vdi cua c i i va 3 giai dogn phdt triin d i l vdi cua dgc:
Hinb 1. S^ phat triln tuyen sinh dye ciia cua cai (Gial doan 1 Cua cii:
Giai doan I: Cua chua thinh thye, tuyin smh dye ming va Irong suit Cdc t i bdo tru'ng ed kich thudc r l i nhd md khing I h i quan sal bang mit thudng.
Giaidognll:Tuyinsinhdgcdang phdt trien. Nang tn>ng ring b i n trong. Nodn sdo e i mdu hai vang.
a, giai doan 2 - b, giai do^n 3 - c, giai doan 4 - d) v i cua due (e) Cde le bdo trung cd kich thudc Idn ban vd dang trong giai dogn lieh luy nhan va nguyin sinh c h i t hinh thinh mit Idp bdo nang bdn ngodi te bdo trirng.
Giai dogn III: Cua dang thdnh Ihyc. Noan sdo md rgng vd ed m i u cam. Cic te bdo trirng Idn han cde giai dogn trude vd bat ddu tieh luy noan hodng.
TRUONG DAI HOC NHA TRANG • 97
Tgp chi Khoa hgc - Cong nghe Thuy sdn
So 2/20li Glai dogn IV: Giai dogn thdnh thye. Vao d i ugiai dogn ndy tuyen sinh dye tang tdi mirc t i i da, tiii ehua tinh l i i l i n , noan sao cd mdu cam hoae dd.
Cd the nhin Ihly mdu cam ICr mai cua. Nang InJng phing lo. cua san sang de tnJng.
1.3. Kich ca tham gia sinh san tan dau Ket q u i nghien ciru cho thiy kich cd sinh san Id cua cd ehieu ring mai nhd nhit 2,8 em va Idn nhit id 3 cm. cua cd khii lirgng nho nhit 8.7g vd Idn nhit 12,Ig cd the tham gia sinh sdn. Sue sinh sdn tuang doi dgt 199 ± 93 trung/cua mg. sue sinh sin tuygt doi dgt 24 ± 9 ln>ng/g cua mg vd khing chenh lich so vdi m i l s i lodi cua ding khie nhu loii S. gennaini vdi sue sinh san tuang doi id 22,29 ± 4,73 tnjng/g cua mg (Le Thj Binh, 2011). Cua cd kfeh ed tmng binh 10 g, s i lugng frung Idn nhll frung binh dgt 238 trtrng/con v i sirc sinh sin 25 tn>ng/g, tmng binh 155 tnjng/con vd sire sinh sdn 21 tn>ng/g.
1 4. Qui tiinh giao vl vi di tmng
Cung nhu cic loii eua biin. qud frinh giao vy cua eua ding diln ra khi eua cdi mdi l i t xie xong, ca the cdn non mIm, iiic nay con dgc diing chin bd lit ngda con cua eii, phin byng (yem cua) cua c^dng md ve phia sau vd dp vdo nhau, C^ quan giao elu cua con dgc cd dgng hinh mui kiim nim d gic chdn byng thu nhit se gin vdo hai l i sinh dye (lo di) ciia con edi nim d gic chdn bd thu 3. Thdi gian moi lan cap dii.
giao vT khodng 30 - 60 phut, qud trinh cap ddi giao vT cd the tien hdnh lap di ldp lgi nhiiu iln vd ed sg Iga
chgn eon due trong khi l i i n hinh giao vT. Sau khi giao vT tmh tnJng dugc gdn vdo 2 hie ehira tinh nam tien trong. phia sau lim ctia con cdi. sau qud trinh giaovi 2 - 3 ngay. tuyen sinh dgc bit d i u phdt triln manh
Q u i frinh d i tnJng cua cua cOng ttrang ||^ nhif cdc lodi cua dong khdc. Cua ding d i tnrng tr^n n4n diy. Trirng mdi d6 cd dudng kfnh trung binh khoSng 1.5 mm CO mdu vdng ddm, ttiing trin, cdng nudcva rdi rgc. Sau dd, eua se thu gom InJng Igi vdo trang y i m bang cac d i i phin phg. Qud trinh dd trimg va thu gom trirng kdo ddi khodng 2 den 4 gid. Hi^n tugng dgc bigt dugc ghi nh|n Id sau khi d i trdng xong, cua cai dm tn>ng r i t il xuing nude m i Ihudng bd ien nhtrng nai cd gid I h i cao nam bit dpng vJ trd n i n r i t hung hang khi bj tde ding. Cua rit dl nhd trtrng neu ed tde dpng d i t nggt hodc thdm d6, lay trtrng tir y i m cua. Trong mgt s i trudng hgp, cua mg d i trtrng nhung khdng gom dugc trirng dir^c ghi nhgn bdi Trin Nguyin Duy Khoa vd etv. (2011) 1.5. Qui ttinh phit trien phdi
Khdng giing nhu mot s i lodi gidp xie khac, quS trinh phit trien phii cCia cua ding dien ra trong yem cua cua mg. Phii dugc eua mg i m trong yim vS duge bdo v i cho den luc no thdnh cua con vd thoSt ra ngoai mdi tnj-dng. glal dogn nay keo ddi khoing 1 2 - 1 5 ngdy Phii mdi dugc hinh thdnh c6 mau ving luai vd bit d i u phan c i t d i phit triln. Theo sg phdt tnen ciia phii. cdc l i bdo chit tdp tmng vao giua. hinh Ihdnh cdc ca quan vd nd Ihdnh cua con
9Jf9 99,
Hinh 2. Cac giai doan phat t Su phdn elt vd phii vj hda diu xdy ra trong 6 ngdy d i u . tu ngdy thir 7 den ngdy thir 12 thi x u l l hiin mIm chdn vd mit. Liic d i u mat cd dgng minh ddi mdu sdng. d i i xung hai ben, sau dd to dan v i m i u cung ddm ban vd cuii eimg hinh thdnh d i i mit mdu den vd hinh blu dgc. Tim bat diu hogt ding, nhip ddp y i u v i thua, ve sau nhjp d i p mgnh vd tdng d i n nhip dap l i n , vd d i u nggc chdn hdm phit trien. d i t byng vd c i c ca quan bdn trong hinh
ien phSi cua cua ddng
thdnh, cdc ca b i t dau co bdp. Phii sau khi nd Ihinh cua con v i n t i i p tyc dugc eua mg i m trong yem, dg luc ndy cua con cd Idp v i mim, chua cd khd ndng t g kiim m i i vd t g vd, Sau khi nd, eua con dugc eua mg i m trong y i m khoing 17 - 21 ngSy.
Khi ru cua con ra khdi y i m cua mg dimg 4 dfli chSn bd ndng yem l i n sau 66 dimg d i i chdn byng gSy eua con ra ngodi m i i trudng, thdi gian niy diin ra khodng 2 - 4 ngiy.
Tgp chi Khoa hoc - Cong nghe Thuy sdn So 2/2013
2. Thip nghidm sinh sdn cua dong
Bdng 1. T:^ l# thdnh thgc cua cua nuoi v i ThM gian
01/06/2010 25/06/2010 08/07/2010
S6 cua m^ kiem tra (con) 30 30 30
S^ cua thdnh tti^c (con) 18 22 16 Tmng binh
T»l«
PM 60 73,3 53,3 62,2 Nuii v6 ddng vai tro r i t quan trgng quylt djnh
thdnh cdng trong smh s i n nhdn tao cua ding. Tiiy vio c h l l lugng eua qud trinh nuoi v i md eua bien {Scylla sp.) e i the dd sau 5 ngiy nhung eung ed t h i kdo d i i den 111 ngdy hoac thdm chl Id khdng d i (Tran Nggc Hdi v i etv., 2002). Doi vdi eua dong, sau 20 ngay nudi v i eua b i t d i u Ihly cua i m trung vd sau 30 ngdy thi cua dm trung ding logt. Trong nghidn ciru hien Igi. sau 25 - 45 ngiy nuii vo, cua Bdng 2. Tdng trirdng trung binh cua
bat dau dm tru'ng va dm eon. Dieu ndy cho Ihly thdi gian nudi vo ddi hay ngan phy thuic vdo tirng loai, sg Ihdnh thuc cua cua khi dua vdo nuii v i vd cde yeu t i mdi trudng (Ngd Trong Lu, 2005). Ty le thinh thye ciia eua nuoi vo trong nghiin ciru nay dgt Irung binh 62,2% (bdng 1). K i t qua nudi v i thdnh thgc trong nghien cuu niy l i thip ban so vdi nghien ciru trdn lodi cua dong S. germaini vdi ty ig thinh thgc dao dgng 75 - 85% (Le Thj Binh. 2011).
cua con tip hai nguon cua me khdc nhau Ngu6n cua m^
Nuii Vd trong ao Thu ngodi tg nhiin
Kh6i li/^ng cua con (mg/con) 1 ngiy tuoi
0,51 0,53
8 ngdy tuoi 48.02 47.78
15 ngdy tuoi 94,48 95,51
22 ngay tuoi 466.66 471,91 K i t qud nghiin ciru eho thiy. ndng suit eua con
cOa cua me nudi vo id 17.2 ± 2.6 cua con/g cua me trong khi eon s i ndy cua eua t u nhien Id 18,8 ± 2.9 cua con/g cua mg (P > 0,05). K i t qua uong nuoi cua con eho thay, chung Idng trudng mgnh d glal dogn 15 - 22 ngdy tuii. TJ id song eiia eua eon phy thugc vio mdi trudng, thirc i n vd nai trCi I n . Cua dong Id lodi hung dCr hay tan cdng va an thjt Iln nhau nin trang qua trinh nuii c i n tgo nai an n i p eho cua ding bang cdc i n g nhga va ludi mdu den de cua trti I n (Ngd Trgng Lu, 2005). Kel q u i uang nuii eua ding tir hai nguin nuii v5 vd nguon thu tir tg nhiin khing cd sg khic bigt v i o dao ding lan lugt id 43.7% va 48,2%. TJ Ig song ciia eua thu dugc Bdng 3. Sinh tru'dng vd ty* 1$ Sung cua
trong nghiin ciru ndy eung tuang tu nhu nghiin ciru ciia LeThj Binh (2011) Iren lodi S germaini v&i ty Ig sing dao dgng 44 - 53%. C i c chi lieu ve t i c dg smh trudng dac trung, l i c do sinh trudng trung binh ngdy vd khii iugng sau ciJa cua eon khong ed sg khde bi^t giira 2 nguon eua mg nuii vo vd cua thu tir tg nhien (P > 0.05) (bdng 3). Tuy nhien. cd t h i nhgn thiy mgt xu hudng ring, cua con ciia cua mg thu tir tg nhien ed eic chi tieu sinh trudng eao han so vdi cua nuii vo (P > 0,05) Dieu nay cd the do sg khic biet ve mii trudng song, dinh dudng tardc do gitra 2 nguin cua. Cdc nghiin ciru tiip theo can dugc thue hign de nang cao chit iugng cua giong tir nguon cua nuii vo nhan tao.
cua con tir hai nguon cua me khac nhau ChlsA
Khii lugng d i u (mg) Khii lugng sau (mg) DWG (mg/ngiy) SGR^ (%/ngiy) TJ li sing (%)
Cua ma thu ngoai t^ nhien 0,51 ± 0,06 471,91 ±24,31"
23,11 ± 1,87- 32,94 ± 7,31-
48,2"
Cua me nuoi vfi trong ao 0,53 ± 0,08 466.66 ± 62,18"
21,05 ±3,23"
30,72± 11,31"
43,7"
TRUONG DAI HOC NHA TRANG • 99
i^^aai
Tgp chi Khoa hoc - Cong nghe Thuy sdn So 2/20n
IV. Kf T LUAN VA Kif N NGHj 1. Kit luan
Miia vu smh s i n cua eua keo ddi tir thing 4 den thdng 10. luyen sinh dye trdi qua 4 giai doan phdt tnen. Cua cd khoi lugng 8,7 -12.1 g vd chieu rgng mai 2,8 - 3 cm cd t h i tham gia sinh san. Sirc sinh sdn tuyet doi 24 ± 9 trtrng/g. sue sinh sin tuang d i i 199 ± 93 trung/cua me. Qud tinh phat trien phdi keo d i l 12 - 15 ngdy, thdi gian cua me i m con tir 17-21 ngay.
Ty ig thinh thgc cua eua b i me nudi vo id 62,2%. Nang suit cua con Id 16,8 ± 2,9 eua con/g cua me d i i vdi eua mg thu ngoai tg nhien vd 17,2 ± 2,6 eua con/g eua mg doi vdi eua mg nudi vo.
Sau 22 ngiy uong. eua eon dat toe dg tang trirdng 21,21 mg/eon, vd ty le sing dat 43,6%.
2. K i l n nghj
Can tiip tyc t i i n hdnh them cde nghiin CLPL v i d i e diem sinh hge sinh sdn eOa cua ding trong dd nhan mgnh anh hudng eiia mdt s i yeu l i sinh thdi v i Ihuc an len sinh trudng. tJ le sing v i sv thanh thuc sinh due cua cua bo me trong d\hu ki§n nudi nhiL
Can l i i n hanh cde nghien eiru ve anh hu'dng eiia thire an. edc yeu t i mii Irudng. gii the, m§t do.... lin sinh tardng, phit tnen va ty ie sing cDa cua eon nham hoan thign quy trinh uong giing eua dong.
a germaini, Rathbun. 1902) va tim loai in Toan quoc lan thii IV. Dai hoc Nong
a biSn {Scylla sp,). Tap TAI LIEU THAM KHAO
Tieng Vift:
1 LeThi Binh, 2011.NghiSn cmi cho sinh san nhan tao cua dong (Somanniathelphus thuc an thich h^p cho uang nuoi cua d6ng con. Ky yeu HQI nghi Khoa hoc Thiiy s;
LSm Tp. H6 Chi Mmh
2 Ho^g Dlic D!it. 1995. Ky thuat nuoi cua biin. NXB N6ng nghiep
3 Tran Nggc Hai, Hassan, A., Law A T, Shazili N A., 2002 Mpt s6 vin d% ttong nuoi v ch! khoa hpe Dai hgc C4n Tha, 236-241
4 Triin Nguyen iDuy Khoa, Ngo Qu6c Huy va Trin Ngoc H^, 2011. NghiSn ciiu smh san va uang nuoi cua dong Somanniathelphusa germaini Tap chi Khoa hpe, ttang 70 — 76.
5. Ngo Trpng Lu. Thai Ba H6. 2003 Ky thu^t nu6i dac sdn QU6C nggt tSp 3, NXB Nong nghiep.
6 Thai Thanh Diiang, 2003 Mot so loai giap xac thucmg gap ct Viet Nam Trung tam tin hgc - Bg thiiy san, Ha N^i.
7 Nguyin Trpng Nho, Ta Khac Thudng va Luc Minh Diep, 2006 Ky thuat nuoi giap xac. NXB Nflng Nghiep.
8 Nguyin Ca Thgch, 2007. San xuat giong va nuoi cua xanh thuong phSm 6 Viet Nam. NXB Nong Nghiep.
9 DangNgpcThanh, Thai Tran Bai, Pham Van Mien, 1979. Djiih loai dong vat khong xuong sflng nuoc nggt BSc Mien Nam.
NXB Nong nghiep.
10 Dang Ngpc Thanh va H6 Thanh Hai, 2001 Giap xae nu6c ngot, Trong- Dgng Nggc Thanh va etv. (Eds ), Dpng vat chi Vi?!
Nam. NXB Khoa hgc va Ky thuat, Ha Ngi, trang 55-92.
TtengAnh:
1 i. Bauer, R T. (2004), Remarkable Shnmps - Adaptattons and Natural. History ofthe Carideans University of Oklahoma Press, Oklahoma City, Oklahoma 316 pp
12. Churchill, G.J., 2003. An investigation mto the captive spawnmg, egg characteristic and egg quality ofthe mud crab (Scylla jerra/a) in South Africa In Workshop of mud crab culhue, ecology and fisheries, Can Tho University, Viemam.
13. Islam, M S., K Kodama and H Kurokura, 2010 Ovarian Development of Mud Crab, Scylla paramamosain in Tropical Mangrove Swamps, Thailand. J. Sci. Res. Vol. 2(2) 380-389
