HOI NGH! KHOA HOC C O N G N G H E SINH HQC ToX
NGHIEN cO'U S A N X U A T G I 6 N G 6 C N H O I {Pila polita Deshayes. 1830) TRONG DI^U KIEN NHAN TAO
T9 Thj Binh, Nguyin Thj Binh Dg/ hgc Vinh
T 6 M TAT
Sin )ni4t giong 6c nhSi (Pila polita Deshayes, 1830) trong difiu kien nhan t p dugc thifc hi^n qua 3 buoc. Budc 1: nuoi 6c b6 m? cho sinhsantrongb£c6dayl>iJuvab£daykhdngc6biin(ddy tro), cahaibedeudupc t^obodi, datdSlimncrt choocsinhsan. Budc 2:
Tien hanh ap tning dc bing hai phuong phap la ap Iren be chudi v^ ap trong khay Dh\ra, Buoc 3: ucmg 6c con mcri nd 16n oc giong bing hai hinh thtrc uong la uang trong giai vi uong trong be composite. Cic ihi n g h i ^ du^c ti^n iianh t^i tr^i th\ic nghiem NTTS nuac ng9t ciia khoa Nong Lam Ngu, Tiudng Dai Hpc Vinh nim tren dia b ^ thi tran Hung Nguy€n, Nghi An tir thfing 3 den thang 10 nam 2012. Kit qua cho tfiay, khi nuoi 6c b6 me cho sinh san trong be cd ddy biin c6 ti 1? tham gja sinh san (8,8-93,3%) cao htm so vdi Irong be khong co day biin (3,4-75,6%). Sii dung phuang phap kp trung tren be chu5i cho ti 1$ nd (55,36-88,80%) cao han rat nhieu so vdi ap trirng trong khay nh^a (33,30-55,31%). Sau 28 ngiy uong 6c con trong giai cd ldc dg tang tnrdng ve chiiu dii va khdi lirong (13,09 mm/con, 0,47 g/con) cao hem so voi uong trong be (11,52 mm/con; 0,38 g/con). Tl le song cua 6c con trong qui trinh uang nrang d6i cao, dao dpng tu 69% din 84%)
Tir khoa: Pila polita, sinh san, ty le nd, ti 1? s6ng, tang tnrdng DAT VAN D £
Oc nh6r Pila polita Ik loai 6c nude ngot pho bi4n, phan b6 d Dflng Dirang, Indonesia, Trung Quoc vk Thdi Lan. Chijng s6ng trong ao, ruOng, vung d6ng bing vk trung du (Dillon R. T., 2000). Cho din nay da co nhDng nghien ciru vk sinh thdi, phdn b6, vai trd vd tdc hai cua m$t s6 loai 6c nu'd'c ngpt trong 06 cd oc nhoi P. polita. Theo Burch J. B. vd Upatham E. S. (1989), Pusadee Sri-aroon et all (2005), 6c nh6i P. poiita Oagic xem Id mflt trong nhO'ng lodi 6c nu-ac ngpt c6 vai trd r^t quan trpng trong y hpc. Thaewnon-ngiw et all (2003) cho biet 6c nhol P. polita hi^n dang dupe xem nhir mflt bl^t dagc de chifa bflnh v6 da cOa ngu'di dSn dia phu-ong d mien Nam Th^i Lan.
Cf Viflt Nam, dc nh6i Pila polita Id lodi dflng vdt thdn mSm nude ngpt co mdt hau nhu* khdp vCing dong bang khu vi/c Nghfl An, Ha Tfnh. Hifln nay cdc san phim cua lodi dong vgt than mim ndy ban trfln thj trifdng du-di dgng ddc san, hiu nhu- Id tir khai thdc tg nhien, ho$c tir nguon con gi6ng thu nhgt trong t^r nhlfln d^ nudi, vl v|y khdng chii dflng vk dang ngdy cdng khan hiflm. Loai 6c ndy co the ch6 biSn du'di nhilu dang sdn phim khdc nha 6c om chu6i ddu, 6c hip gfrng, biin 6c, . vd nd cdn cd thi du'crc si> dgng Idm nguydn liflu phijc vu cho y hpc. Do dd, nhu cau v l lodi 6c ndy dang ngdy cdng tang vd khd nang phdt hiln nuoi chOng cQng dang ngdy cdng md rgng.
Hifln nay, trfln Thi gidi vd d Viflt Nam chua cd nghifln CLPU ndo v l ky thuflt sdn xuit giong lodi 6c nhfli ndy. VI v^y, nghidn cuu ndy dupe th^pc hifln nham khdo sdt cdc ylu t6 dnh hudng din qud trinh san xuit gilng 6c nhoi, tir dfl ddm bdo tinh 6n djnh cua quy hinh cflng nghfl sdn xuit gi6ng cho d6i tupng ndy, tgo co sd d l phat triin nghl nufli, bo sung thflm mflt d6i tupng nufli thuy sdn nude ngpt cfl gid trj kinh t l cho ngdnh nufli trong WiOy sdn nude ngpt Viflt Nam. Mdt khdc, ddy cung Id mflt gidi phdp nhim gidm dp lgc khai thac nguon 6c nhfli tg- nhlfln, chu dpng cung cap con gi6ng trong vi$c nufli thLFcmg phim vd eung Cmg sdn phim cho thi tnfdng.
NGUYEN LI^U VA PHirONG PHAP Vgt lifu nghifln ciru
Nguin 6c gilng bfl dupe chpn Ipc vd thu mua tO cdc ngu ddn khai thac tgi ode dja phuong nhu Nam Ddn, Hung Nguyfln 6e thu mua phai khoe mgnh, kich co' 20-30 con/kg, vo con nguyfln v^n, mdu sac dae trung cOa lodi.
Phuvng phdp nghien ciru
Nu6l thuin dirdng 6c bo mg va cho sinh san
> Dilu ki#n be nufli thuln dudng vd b l cho sinh san
B l nufli thuln dudng 6c: Thi tieh 1,5 m^, sau khi dupe vfl sinh sach se ta tiln hdnh cap nude khodng 40-50% thi tich vd tha bflo hoa ddu vdo vdi dfl phu khoang 1/2 difln tich mgt nude trong b l , Phin khong thd beo d l rdi thi>c dn cho 6c.
B l eho 6c sinh sdn. Tiln hanh chuan bj 2 b l khdc nhau d l cho 6c sinh san. Mflt b l ed day bim, mflt b l ddy tro (khflng ed biin). Tnang mfli b l diu tao mot bd dd, ed dip dit bao phii. Id noi d l Ic sinh san. Mli don b l nufli 15 cgp 6c bo m?.
Tren m6i b l diu ed mai che han chl khoang 50% anh nang true tiep chilu vdo b l nham hgn ehl SI,F fang nhiet dfl nudrc trong nhO'ng ngdy ndng nflng.
Cham sdc vd quan ly 6e b6 mp
Cho 6e^b6 mg an 1 lan/ngdy, vdo bull chilu t l i (17h). Khli lugng tht>c an cung d p bang khodng 3-5% kh6i lupng Ic trong be. Thdc an cho 6c la cam ggo. Id s i n , . . „ ngoai ra 6c eon su dung nguon thire an xanh td bdo hoa dau dd dipcrc ' tha trong be. Trong qud Wnh cho 6e dn ehCing tfli da theo doi hogt dflng bat mfli cua I c d l dieu chinh luong thi>c Sn cho phu hpp. thiy thieu thi bo sung them hoge thira thi giam di Hing ngdy quan sdt hogt dflng cCia 6e. theo dfli edc ylu it) mfli tnjfl'ng (nhiflt dfl vd pH), dfl sach hay bin cua nude Oe tiln hanh thay nude.
C CONG NGH^ SINH H g U TOAN QUOC 2013
Thu trimg vi ip trimg
Sau khi 6c dfl, chd eho v6 canm aia bi>ng ct>ng lgi, tiln hdnh thu cde ehCim tamg 6c trfln bd dat dd hong b l , rua sgch, dim s6 lugng chum trirng, so lugng trtrng/chum roi cho vao dyng cg I p . Tiln hdnh ap tnJng bang theo 2 phuwng phap sau:
Ap tnJng trong khay nhga : Sir dung cdc khay r^g3 cd kich thudc 5 x 5 x 2 cm d l I p tning. Cdc ktiay dupe ve sinh sach se sau dfl d$t Ining vao khay, phii mflt It re bflo Ifln trfln d l giO am.
Ap trirng trfln bg ehuli: DOng thdn cdy ehu6i non d l Idm gid t h i , edy chu6i dugc che Idm dfli, n>a sgeh, Idt mflt Idp bOn mflng Ifln trfln r i i dgt tn>ng Ifln d l I p . Phu mgt it rg bdo Ifln trfln d l giu I m .
> Cham sdc quan 1;^ hirng 6c trong qud trinh I p
Vifle theo doi tn>ng trong qud trinh ap dugc tiln hdnh hdng ngdy, quan sdt vd do nhidt dfl mfli trudng noi Ip hiing.
Trong qud trinh I p tn>ng thi bg chufli ed hifln tupng bi chuyin mdu, thdn hoi mim ra. Vi vay ein phdi thay be chuli mdi cfl ttil ddm bdo dio trung phdt triin binh thudng. Thtrflrng thi cir 4-5 ngdy tiln hdnh Biay bg chuli 1 lan. ICii I p trong khay se thudng xuydn xdy ra hign tugng khfl trung do thieu nude, vi vdy phdi thudng xuyfln phdi giir d$ I m cho trdng trong qud trinh I p bang each lay cdy bflo ddu nhdng nude phO len trfln o trirng.
tfcmg 6c con mdi nd len 6c gi6ng
dc mdi nd Oagc dua vdo b l composite kieh thudc 1 x 1 x 1 m hogc giai kieh thudc 1 x 1 x 1 m d l uong nufli Ifln 6c gilng (ed 0,4g). Thdi gian uong nuoi Id 28 ngdy. Mdt dfl uong Id 500 con/m^. Giai dogn diu khi l e eon mdi nd, eho chOng dn cam ggo mjn. sau 15ngdy cho 6c an thflm Id san, bflo,. ...Thudngxuydntilnhdnh vfl sinh giai vd b l nufli.
Phuong phap xir \iis6 l i i u
Todn bfl so liflu dugc xir li bing Excel 2010 vd phuong phdp thing ke sinh hpc si> dgng phin mim SPSS 16.0 K£T QUA VA TH AO LUAN
Kit qud nuoi thuan duong 6c b l mg
Oc b6 mg dirpc thu mua tCr tg nhifln v l nufli ^ u l n dudng trong he (nudi chung I c di,Fc vd 6c cdi), sau vdi ngdy nufli mflt s6 6c bi chit rdi rdc, nguyfln nhdn cd thi Id do chOng bj s6e khi dua vao moi trudng mdi. Logi bfl ede cd t h i ehit, thay nude trong b l nufli vd tilp Igc nufli thuln duong nhQng ed t h i cfln khofl mgnh. B 6 sung thflm 6e b6 me vdo be vd nudi cho din khi 6c b6 mg quen vdi dilu kifln moi tnrdng nufli trong b l . Chgn 6c b l me khfle mgnh, kich cd 20-30 con/kg, chilu ddi £40 mm, vd cdn nguyfln vgn, mdu sac dgc trung eiia lodi
Bing 1. Kich thute vd kh£l lirgng trung binh 6c b l mf ch9n cho sinh sin Dgt (thing/nSm)
1 (3l20t2) 2(4/2012) 3 (5/2012) 4 (6/2012) 5 (7/2012) 6 (6/2012) TB
B l CO dky bun P (g/con) 28,50+2.54 32,16±2,75 28,75±2,50 32,34±3,72 34.6±4,74 34,97±4.84 31.87
L (mm/con) 50,90±2,72 50,07±2,43 49.06±2,12 50,06±3,52 51.34+6,31 51.2±5.94 50,44
B l khong ci P (g/con) 26,73±2,05 31,61±2,68 31,11+2,78 30,56±3,58 34.56±4.09 34.53±4,32 31.51
> ddy bim (day tro') L (mm/con) 49,62±2,29 48,57±2.76 49,78±3.03 47,98±3,27 49.37±5,99 51,5±6,29 49,47 Ghi diO: P: khSi luang: L: chiiu diii
Qua cde s l liflu d Bdng 1 cho thay, todn bfl 6c b6 mg dua vdo trong b l nufli eho smh sdn qua edc dgt diu efl khli lugng tir 26,73-34.97 g/con, chilu dai tir 47,98-51,5 mm/eon, Trung binh v l khli lupng 6c bo me d b l ddy biin dgt 31,87 g/con vd d b l ddy tro dgt 31,51 g/con Id tuong nhau, ve chilu ddi Uian dgt 50,44 mm/eon d nhflm ddy bun, 49,47 mm/con d nhflm diy tro, tuy nhdm d b l day biin cd cao hon nhdm d b l day tro mflt It, song su khdc nhau Id khdng ddng k l . Theo Trin Thj Kim Anh vd dtv (2010) thi 6e nhii cd kieh thudc Idn (>40 mm) thi cfl sde sinh sdn cao nhat. Nhu vfly, kich thudc I c b i mg dua vdo sinh sdn nhan tgo trong nghien etru ndy cua diOng tfli tuong d6i phu hgp vdi yeu clu. dgt kich thudc sinh san.
Kit qua sinh sdn cua 6c tgi cac b l
Cdc kit qua ttieo doi khd nang sinh sdn oJa I c tai cdc b l dugc t h i hifln d Bang 2.
Bing 2. Kit qui cho sinh san cOa 6c tpi cdc b l Dpi
1 2 3
% bebl me Dky biin 93.316.67*
88.9 ± 7.70°
8 1 . 9 * 7 , 6 9 "
tham gia sinh s i n D a y t r » 75.6 ± 7.70"
62.2 ±3,85*
68.9 ±7,89'
S u e sinh san Say b i m 220±16,7*
217±16.1*
215±12,1' trung binh
Day t r e 207+15.0' 195+15.6' 205±16.7'
ui-,1 wriui i/urtA u/v- r>/Swr; MTLUC^I 1 uou, „ur,A u,T^ /-Aw,5 Mouu uiiwucJ'-IHF'"
HOI NGH! KHOA HOC CONG NGHESlRfrHOft'fi;;
4 5 6 1 B
84,4 ± 3,85*
8.4 ± 3,67"
44 ±6,64"
66,81
64.2 ± 3,65' 3.4 ± 0.66' 8.5 ± 2 , 1 7 ' 47,13
207±15,0' 68122,6"
117±38.9"
174
195±15,6' 81±3,51' 73±34,1' 159
Bdng 2 cho thiy, ty lfl tham gia sinh san cOa 6c me kha cao, cao nhit dgt 93,33% o trong be cd ddy biin trong dgt 1 v^
ttiap nhit Id 3,4% d be ddy tro trong dgt 5. Tnjng binh ty Ifl sinh sdn qua 6 dgt dgt 66.81 % d nhdm^ b l ddy bOn vj 47,13% d nhdm b l diy tro. Ty l# sinh sdn dia 6e nufli trong b l diy bun cao hon ddng k l so vdi nhflm 6c nufli trong t^
ddy tto. Qua cac kit qua ban d i u ndy cd t h i nh|n xdt. cOng m0t^ngu6n 6c b6 n ^ dugc nudi vfli c h l dfl cho an vd chfl^
sdc nhu nhau nhung ty lfl sinh sdn eOa dc b6 me nufli ttong be Sky bin cao hon so vfli 6c b6 mg nufli trong b l ddy khdng cd bdn. Dilu ndy cd ttw do 6c s6ng trong tg nhiSn da quen vfli dilu kifln faOn filt hon Id bd tflng hay eompostte, a
Hlnh 1. dc mf dang de trvng Hlnh 2. ChCim tn>ng 6c mfli Oe
Si>e sinh san eiia 6c dao ddng tt> 73-220 qua/ea t h i , cao nhit Id d nhdm nudi ttpng b l ddy bCin d dgt 1 vd thip nhlliaj nhdm nufli ttong be ddy bun d dgt 5. Trong binh ede 6c d nhflm nufli trong be day bun da de 174 tt^ng/6e (6) vd 19 tn>ng/6c (1) d nhdm nudi ttting be ddy tra. Mflt lan niia cdc kit qud ndy cho ttily 6c nufli trong b l cfl ddy biin gdn gijif vdi dilu kign tg nhifln hon nSn ed khd nang dd bi>ng cao hon so vdi 6c nuoi trong b l ddy ttcr. j « Tuy nhifln, qua Bdng 2 ta eung Uily dgt 5 vd 6 fi Ifl tham gia sinh san cua 6c mg vd sire sinh sdn Uilp d cd hai b l ^ 3 biin vd ddy tto Theo Trin Thj Kim Anh vd Ov (2010) 6e nhoi Uidnh tfiyc sinh dgc trong Uidi gian h> ttidng 3 d l ^ l 10, bt)ng dfl ty lfl ttidnh Uigc cao nhit tir thdng 4 din thdng 6 (dat 76-98%). Nhu vdy, miia vg sinh sdn cua 6c n t i ^ H ttidng 3 din ttidng 10, vy sinh sdn diinh tgp biing tir thdng 4 din ttidng 6. VI v|iy dgt 5 jttidng 7) vd dgt 6 (tfiaH khflng phdi Id miia vg sinh sdn chinh eOa 6c nhoi nfln dan din ti lfl tham gia sinh sdn cua 6c mg vd si>c sinh sdnaB
dgt ndy ttilp. i Ket qud I p trimg oc theo 2 phuomg phap
Quan sdt bfln ngodi cd thi nhgn thiy rat d l ddng su thay doi mdu sic cCia edc chiim tning tir liic mfli dfl din khi tn)i nd. Cdn cir vdo dgc diim ndy, chiing ta cd ttil biet dugc thdi gian tti>ng 6c nd d l chuin bj ede gid t h i vd cdcd\ni<
dgng 6c eon, eung nhu chuin bj v l thuc an d l eho 6c con, nham ndng cao ty Id s6ng cOa 6c eon.
Bang 3. Ket qua ap n^ trirng 6c bing cdc dgng cu ap khac nhau D g t
1 2 3 4 5 fi TB
Ap tn^ng trong khay nhg'a S6 l u o n g t l 10 10 10 10 10 10 10
S6 l u g n g trtrng (qud) 2227 2218 2120 2020 816 1111 1752
s 6 l u g n g 6c c o n (con) 1977 1916 1770 1531 473 615 1380
T i i 9 nir{%) 88,8 86,4 83,5 75.8 57,9 55.36 83,63
A p tn>ng trSn be chuoi S l l u o t i g to 10 10 10 10 10 10 10
So l u g n g t r u n g (qua) 2007 2108 2210 1969 652 1256 1700
S o k r g n g l c con (con) 1110 1018 967 757
558 921
Tllfni
(%)
55,31 48,29
^ I 3 h |
H ^ . ^ ^ ^ j a l
1^3
CSc s6 mu a Bang 3 cho thay, phirang phap ap trSn be chuoi cho ty l# nft cua tning 6c cao hrni r S t S S I phinmg phap ip Irong khay nhira. TJ 1$ no tnina i p IrSn b? chuoi a?t tnmg binh 83,S3% so vffl 43 9 2 V l i l i i i r trong khay nhua. NguySn nhan c6 the la do ytu lo 30 4m »a nhiet dO. khi ip trtmg J§„ | j ^ ,^^^^ • J'Xj^
hon va ciing mat hoTi. C6n khi 4p tning trong khay nhira, du diroc tirdi nir6c giir Sm ntn,„g „ ^ S ^ i l ^ biet IS dot thi nghiem thi> 4, 5, 6 (6,7,8/2012). a nhOng dot nang nong, nhia do khdng kh, w« J X T I Qua cac kit qui tr6n c6 the nh#n xet, phirong phip ap trtrng 6c tren be chuSi Co hi^u quj hon n h i i . m"
phap ap Inrng trong khay nhira.
Ket qua irofig 6c con moi no len 6c giong
a hon nhieu so I
Thi nghiem irong nuoi oc con trong 28 ngiy (4 tuSn), cac ket qua v6 tang tnrdng cua 6c con a i , , ^ ^ ^ ^ ^ , |
'l|ESl!Br- JC CONG N G H f SINH H p C TOAN QUOC 2013
Bang 4 . Tang tru>frng c Chi tifiu C d 6 c t h d (g/con. mm/con) 0 5 6c thu (g/con,mni/con) ADG
j a 6 G c o n d cdc hinh t h u c khac nhau
P ( g ) L(inm) P ( 9 ) L ( m m ) P (g/ngdy) L(mm/ngdy)
6 c u v n g trong giai 0,03 ±0.0096"
3.97 ±0.632*
0,47 ± 0.010*
13.09 ±1,025'' 0,016*0,0003"
0,33 ±0,004"
6 c ircmg trong be 0.03 ±0 0089"
3,96 ±0.705"
0,38 ±0,016' 11,52 ±0.96' 0.012 ±0.0005"
0.27 ±0,008'
Cdc kit qud tten Bang 4 eho thiy, kich thudc ciia cdc 6c con luc thd Id nhu nhau, sau ttidi gian uang nudi 6c duge trong nudi frong giai khli lugng vk ehilu ddi d^t (P: 0,47g/con, L:13,09mm/eon) cao hem so vdi 6c dugc uang nudi tttmg bl(P: 0,38g/con, L: 11,52mm/con). Tie a$ tdng bvdng ttung binh ngdy cOa 6c dugc ucng nuoi ttong giai dat ( P:
0,016g/con, L :0,33mm/c(Hi) cOng cao hun cdc 6e dugc ucrng nudi ttxing bl(P: 0,012g/con. L :0,27mni/eon). Nguy§n nhdn din din sg chenh l§ch ndy ed t h i Id do grai dugc dat trong ao nen c6 the moi ttirdng ttidng thoang ho'n vd cdn ed ttil chOng t$n dgng thdm dugc mdt It thdc dn san cd ttnng nude ao. Kit qud phdn tich thing ke v l chilu ddi, khli lugng va ^ d$ tdng ttirdng binh qudn ngdy cua oe qua 28 ngdy aang nudi cho thiy cd su khde bt$t ed i nghTa ttiing kd (P<0,05) giO'a edc hinh thirc ucng nudi khdc nhau.
[flnh 3. TDTT binh qudn ngdy v l khoi lugng cila oc thi nghidm Hinh 4. TDTT binh quan ngay v l chieu dai ciia 6c thi nghifm
<lt qud ttieo ddi tie d9 tang ttudng binh quan ngdy cOa 6c Nhoi giong thu duge tai Hlnh 3 vd Hinh 4 eho ttily TDTT ilnh qudn ngdy v l khoi lugng vd ehilu ddi d ede hinh thuc uong khde nhau Id khac nhau. Qua hinh cung cho ttily tie 10 tdng trudng binh qudn ngdy v l khli lugng vd chilu ddi eiia I c Nhoi khi uong trong giai ludn ludn cao hon khi udng iuOi ttong b l d ^ t ea edc lln thu miu.
i If sing ciia 6c trong qua trinh uong nudi
Hlnh thirc uo>ng h 5. Ty 1$ sing cda 6c khi uong d cdc hinh thirc khac nhau
nliMll sing eiia 6c dugc aang nuoi d trong b l sau 28 ngdy dgt 84% cao hun so vdi I c dugc uong nudi d trong giai
HOI NGH! KHOA HOC CUNO. NGHb S f f l f f f l ^ C T C
(69%). Kit qud ndy cd ttil do 6c dugc mmg nudi ttong giai d#t ttong ao, 6c con diju tdc dpng cua cac yeu ui ii>6i tr^^ig nhu nhi?t do, pH vd mpt s l y l u to khac, md cac ylu t l mdi trudng nude trong ao lgi ttiudng cd sg giao dOng Idn hon ^ nhilu so vdi nude d frong be, do dd da dnh hudng h*i tJ 1$ song dia 6c con irong nudi frong giai. Phdn tich ANOVA mOt i nhdn ^ d l so sdnh su idiac bi?t v l tf Id s6ng giCra cac hinh ttiuc uong nudi cd sg sai khdc cd y nghTa(P<0,05). * KfTLUAN
Trong dilu ki^n sdn xuat g i ^ g nhdn t?o 6e nhii, 6c tm me Iga chgn cho sinh sdn phii khde mgnh, kfch co 20-30 con/kg, ehilu ddi 240 mm, vd edn nguydn vgn, mdu sic ddc trung ciia lodi. Nudi I c b l mp sinh sdn ttong b l cd ddy biin t i t hori b l khdng cd ddy biin(ddy fra). Ap frirng 6c ttBn bg chuli cho tJ 1^ nd cao hon I p frung ttong khay nhga. Trong qua frlnh I p nhi|t dp cdng cao thi thdi gian nd cdng duge nit ngin nhung tJ 1$ I p nd l^i giam. Giai dogn uang tir Ic mdi nd Idn oc giong (^ 0.4g) ndn uang nudi trong giai d^t ttnng ao d l dat ti 1$ s6ng vd t6c d$ tdng ttirdng cao.
TAI U^U THAM KHAO
Trdn Thi Kim Anh, Ta Thj Binh, NguySn Thj Binh, Nguyin Thj Thanh Hoa (2010). Nghidn cdumdts6d$c aim smh hgc sinh sin cua dc nh6/ {Pila polita Deshayes, 1830). Tap chl Wioa hgc- Tnrdng Oai Hpc Vinh. Tdp 39. s6 3A. 2010, Trang 5-14.
Burch J . B ^»d U p a t t i a n E . S . (1989). Med(ca(//importa/i(mo//usks o f Thai/and J. Med. ppl Malacol. 1.1-9.
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Thaewnon-ngiw et al. (2003). Ostribution ofPSa polita In a southern province of Thailand. Joint International Tropical Medicine Meeting JITMM 2002, Bangkok, Thailand, vol.34, pp. 128-130.
SOME INITIAL RESULTS STUDY ON SEED PRODUCTION OF APPLE SNAIL (P//a po//fa Deshayes, 1830) IN ARTIFICIAL CONDITIONS
Ta Thi Binh, Nguyen Thi Binh
Faculty of Agriculture - Forestry - Fisheries, Vinh University
SUMMARY
Seed production of apple smails (Pita poliia Deshayes, 1S30) in artificial conditions have to follow diree steps. First step: culture broodstocks for reproiduction in the tank with mud on bottom and the tank without of mud on bottom, all tbe tanks have created by the cliSs, soil wdiere is places for reproduction of apple snails. Second step: Incubate snail eggs by two methods: Incubate snail e ^ on the banana trunks and in the plastic tiays. Third Step: Nursing new-hatched snails to seed snails with two forms, they are: nursing new-batched snails in para and con^site tank. We obtained initial results: Brood broodstocks cultivated in tank with mud on bottom have tbe rate of participating in reproduction firom 8.4 to 93.33%, higher thanlhat of cultivated in tank without mud on bottom, it is only &om 3.4 to 75.6%. Tbe result of incubated of snails eggs on banana trunk have hatched rate higher than incut>ated on plastic tray (55.36 to 88 80%incomparison with 33.30 to 55.31%). After 28 days of nursing, the growth of small snails in the para reached 14 21 mm/individual of length and 0.55 g/individual of weight are higher than that of nursing in tank (12.63 mm/individual of length and 0.48gr/ individual of weight). Survival rate of nursing snails is relative high, it is about 69 to 84%.
Dja chl: Ta Thj B i n h , Khoa NOng Ldm Ngu - Dal hgc Vinh, OT. 0984.596.189, Email, [email protected]