KHOA HOC CONG N G H i
BEIVH IVAM a CA T A M MEiA {Acipencer SfuMenstaeatii Br&ntit: a n d R a t z e b u r g , 1 8 3 3 ) VA
CA TAHi XIBERI [Acipencer isaerii B r a n d t , 1 8 6 9 ) IVUdi THUCmiG P H A M TAI LAM DOIVG
T6MTAT
Vo Thg DiingS Vd Thi Dung^
Da thuc hien nghien cuu thanh phan nam bat gap va nam cd kha nang gay bfinh cho ca tam Nga (Acipencer guldenstaedtii Brandt and Ratzeburg, 1833) va ca tam Xiben (Acipencer baerii Brandt, 1869) nuoi thuong pham tai Lam Ddng. Tong so 128 mSu ca tam, bao gdm 58 mlu ca tam cd d^u hieu bi benh nam (30 ca tam Nga va 28 ca tam Xiberi) va 70 mhx ca tam Xiberi khoe da duoc su dung de nghien cihi benh nam. Ket qua cho tiiaiy, benh mat nhdt, loet than, hong mang la nhimg bfinh do nam gay ra d ca tam nudi Da phan lap duoc n^m Saprolegnia sp., va Aphanomyces sp. Ty lfi nhiem nam Saprolegnia sp. d ca tim Nga nuoi ao va nuoi Idng tuong iing la 22,2% va 16,7%, b ca tam Xiberi nuoi ao va nuoi long tuong ung la 35,7% va 21,4%. Ty le nhiem nam Aphanomyces sp. d ca tam Nga va ca tam Xiberi nudi ao tirong ung la 5,6% va 7,1%; khong bat gap nam nay d ca tam nu6i long. Ket qua cam nhifim cho thay, Saprolegnia sp. la tec nhan gay benh cho ca tam Xiben.
Tu khda; B$nb nam, ca tam Nga, ca tam Xiberi, Lam Ddng.
1 . BAT VAN BE
Ca tam tit lau da la doi tuong nuoi quan trgng b nhieu nuoc trfin the gioi. Tuy nhifin, dich bfinh noi ehung va bfinh do nam gay ra noi rieng da gay thief hai khong nho cho nghe nuoi ea tam b nhi^u noi (Bauer etal., 2002), mac dfi vay, hien co rat it thong tin vfi bfinh do nam gay ra duoc cong bd. Tai Vifit Nam, ea tam Nga (Acipencer guldenstaedtii Brandt va Ratzeburg, 1833) va ca tam Xiberi (Acipencer baerii Brandt, 1869) da la doi tugng nuoi rat quan trpng tai mot so dia phuong nhu Lao Cai, Lam D6ng... trong nhiing nam qua (Vo Thg Dung, Nguyfin Viet Thuy, 2013; Vo Thfi Dting va cong su, 2011). Gan day, bfinh dich da gSy thifit hai Ion cho nghe nudi ca tam, co nguy co anh huong den tinh ben viing va kha nang phat tnen mo rong doi tugng nay. Dgn nay, da co mot sd cong trinh nghien ctiu vfi bfinh oca tam dugc cong bd, nhuVo The Diing, Tran
Thi Bach Duong (2011); Vo The Dung va cgng su (2011; 2014); Vo Thg Dung, Vo Thi Dung (2014;
2016; 2018), nhung chii ygu tap trung vao cae benh Ufin quan dfi'n ky sinh trung va vi khuan. Chi cd 02 trong so eac cong trinh noi trfin la Vo The Dung, Tran Thi Bach Duong (2011) va Vo Thg Diing va cgng su (2011) co mot it thdng tm hfin quan dgn bfinh nam b ca t ^ ; Mac du bfinh nam eung la benh kha pho bign va da gay ra nhieu thifit hai cho cac loai thuy san b nude ta (D6 Thi Hoa va cgng su, 2004).
2. VAT UEU VA PHUDNG PHAP NGHIBU CUU 2.1. vat 11^ nghifin aiu
Tdng sd 128 ca tSm thuong pham bao gom 30 ca tam Nga va 98 ca tam Xiberi duoc thu thap tir cac trang trai san xuat cr Lam D6ng, thong tin chi tigt dugc trinh bay b bang 1.
Bkig 1. Cd tam Nga vd ck tdm Xiberi duoc dung trong nghifin cihi Loaica
Ca tam Nga bfinh
Sdcon 30
Chieu dai (mm) 550 +100,2
Khoi lugng (g) 780,1 +128,7
Ghichu - Cabiloloet
- Co nhung soi nam mau trdng trfin
Vien NghiSn cmi Nuoi trong thiiy san III Email, [email protected]
75
KHOA HOC CdNG N6Ht
Ca tam Xiberi benh
Ca tiim Xiberi khoe 28
70
538 ±70,2
600.4 ± 35,8
740,2 ± 98,7
800,0 ± 60,1 than
- Ca thuimg bo an, mau sac khong binh thucmg
- Ca dupe dung de mo ta dau hi6u benh ly va phan lap nam gav benh Ca khoe manh, binh thuong dimg de cam nhiem nam
2.2. Phuong p h ^ phan Up va xac djnh thanh phin nam
Ap dung phuong phap phan lap va phan loai nam trfin ca ciia Hatai etal. (1977), trong do, hinh thai va hinh thiic smh san la dac digm co ban de phan loai nam; Quy trinh nghien cuu duoc trinh bay b hinh 1.
Mau benh pham
T
Nuoi cay tren moi tniong PDA 15-25''C
Nuoi cay thuan bang phuang phap 1 bao tii
Nuoi tren moi trucmg ngheo dinh duoug/Shde culture
(^uan sat dac diem hinh thai bao W, tui bao hi. each sinh san bao tu
Phan loai Hinh 1. So do phan lap, nuoi c^y n i n 2.3. Phuong phap thu miu nam
- Ca CO dau hifiu bi benh nam duge giai phau va quan sat miu bfinh pham duoi kinh hien vi quang hoc dg phat hifin sgi nim b eae eo quan co kha nang hi nhifim nhu da (thucmg b eac vet loet) va mang, eo thg thay ro sgi nam 6- do phong dai 400 lin tii cac miu nhugm uot. Nim thuong co dang soi nho, trong suot, CO hoac khong co vach ngan.
- Diing c6n 70% sat ti-iing vfi't loet, mang ca; sau do lay mau benh phim eay trfin moi truong nuoi cay o nhiet do 18 dgn 22'*C; khuin lac cua nam sfi phat
trien sau 1 dfi'n 4 ngay. Lua chgn eac khuan lac nam khac nhau dg liy miu nuoi cay thuin chiing bing phuong phap nuoi cay 1 tfi bao.
2.4. Phuong ph^p nuoi cay t h u ^ chung mOt tg bao
Sau khi bao hi nam dugc smh ra thi dimg nuoc sinh ly de pha khuin lac nam trfin dia moi truong thanh dung dieh bao hi nam; pha loang dung dich ehiia bao tu nim b nong do < 3 bao tii/gigt; hiit 0,1 ml dtmg dieh eo bao tu nim ehuyen sang dia moi truong PDA, trang deu tren be mat moi truong, nuoi eay b nhifit do 15 - 22"C trong 24 gio. Chgn nhiing khuin lac nam mgc don trfin moi truong agar dg luu giu thuan chiing.
2.5. Phuong phap cam nhifim nim
- Ca cam nhifim la ca tam Xiberi khoe (Bang 1).
Ca dirge nuoi thuan duong 1 tuan trong cac be composite 1000 L, nuoc ngot dugc loc sach, khong che nhifit do trong khoang 1 8 - 20''C, sue khi lifin tuc, cho an bang thiic an cong nghifip. Mat do nuoi la 10 con/bg. Chgn ca khoe dtra vao thi nghifim.
- Nim gay nhifim: nam Saprolegnia sp., lay tii ket qua nuoi cay thuan chdng.
- Phuong phap cam nhifim nam Ifin ea: Dua theo phuong phap cua Hatai (1980). Cac buoc thuc hifin nhu sau:
+ Thuan chung nim Saprolegnia sp. trfin moi trudng PDA b nhiet dp 20 - 22''C sau 3 - 4 ngay (eho den khi hinh thanh bao tii nam). Cho 10 ml nuoc cat vao cac dia ldng eo nim dang sinh bao tu, diing tay lie nhe nhang de duoe dich ehiia cac bao tii dinh.
Taeh rifing huyen dich nay vao dng nghifim vo tning.
Dtmg micropipet lay 0,1 ml dich bao tu eho len budng dfim thuc vat noi, kigm tra sd lugng bao hi co trong do. Tii mat do trong dich huygn phii pha loang dg dugc dich co mat do bao tu nim khac nhau.
+ Cam nhifim bang phucmg phap tiem co: chung nim dugc bd tri thi nghifim cim nhifim va bd tri b 3 thang mat do cam nhiem lan lupt la 10^ 10^ 10' 76 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 4/2019
KHOA HOC CONG NGHE
cfu/ml bang each tifim duoi da 0,2 ml dich nim/eon nuoc mudi smh ly tifit tiling 0,8 ca. Nhom ddi ehiing, mdi con ca dugc tifim 0,2 ml ti-ong 12 ngay.
)&. Theo doi thi nghiem
Nghiem thiic DC khong cam
nhiem nam
X
Nghiem thjiic cam nhiem 10^
bao xb/rnl
Nghiem thiic cam nhiem 10"'
bao tii/ml
i
Nghiem thiic cam nhiem 10^
bao tii/ml
- Theo doi tinh trang sue khoe, ty le chet, ty le nhiem nam ciia ca - Danh gia anh bucmg ciia nam tdi sue khoe cua ca
Nuoi cay, phan lap tro Iai tir mau ca benh
X
- Cham soc ca thi nghiem: Theo doi tinh trang siic khoe ca, hang ngay cho an, siphone va thay 30%
nuoc. Ghi chep cac d^u hieu lam sang u ca hi benh.
Ca chet duoc quan sat, giai phau kiem h-a su thay doi o ben trong, thu m^u benh pham de nuoi cay phan lap tro lai.
2.6.Xulj>s61i6u
- Tinh ty le nhiJm nam (TLN) hoac ty le chet tichluy: A(%) = — L * 1 0 0 N.
N
Trong do: yl% la ly le nhiem nam hoac ty le chet, Nj la sd ca bi nhiSm nam hoac bl chit tich liiy, A'la so ca ki^m tra.
3.KErQUAVAniA0lUAN
3.1. Diu hieu c4 bi b^nh v4 thtoh phin nam phan 14p tir c4 tAm nufii thiHmg phim
K i t luan gi6ng loai nam gay benli Hinh 2. Sa do cam nhi^m nim 16n cd
3.1.1. Dau hieu tl^nh ly cua ci tim nhiem nim Ca benh cb cac dau hieu benh ly nhu sau: bo an.
boi gan mat nuoc, mau sic dam hon binh thudng, thuong CO sat vao luoi (ca nuoi long) hay thanh ao (ca nuai ao), vi thd mot sd ca bi lo loet, gay xuat huydt tren than (khac voi trudng hop ca bi xuat huyet do vi khuan hay vi nit gay ra), phan Idn benh ngay cing nang va chet; mot sd trudng hop ca bi 1ft loet nhe vin sdng duoc 1-2 tuJn, vm tnrdng hop tir lanh vet thuong. Mdt sd bl Id thanh cac vet mau tring loang Id hen ttian, vay, giai phSu ben hong khdng thay bat thudng, ca it van ddng. bd an. benh gay chet rai rac.
3.1.2. Thinh phan nam bit gap va ty le ci tim nhiim nam
Hinh 3. C i tam hi n h i t o nim- A, B bi Id Ihtoh v$t-ddm m4u h-ing trdn than, v4y; C bi Icr loet, xuit huyft
KHOA HOC CONG NGHE Bang 2. Ty lfi nhifim cac loai nam trfin ca t ^ nudi ao
va ca tim nuoi long Loai ca
c a t a m Nga Catam
• Xiberi
Nam phan lap Saprolegnia sp.
.Aphanomyces sp Saprolegnia sp.
Aphanomyces sp.
Tv le (ir) 1 Catam
nuoi ao 22,2 (4/18)
5.6 (1/18) 35,7 (4/14) 7,1 (1/14)
Catam nuoi long
16,7 (2/12)
21,4 (3/14) - Bang 2 cho thiy, ca tim nuoi thuong pham tai Lam Ddng bi nhifim hai loai nam la Saprolegrha sp.
va Aphanomyces sp. Ca tam Nga nuoi ao co ty le nhifim Saprolegnia sp. va Aphanomyces sp. tuong
ling la 22,2% (4/18) va 5,6% (1/18); ca tim Xga nuoi long nhifim Saprol^nia sp. voi ty le 16,7% (2/12). Ca tim Xiberi nuoi ao co ty lfi nhifim Saprolegnia sp. la 35,7% (A/U),ya. Aphanomyces sf). la 7,1% (1/14); co 21,4% (3/14) ea tam Xiberi nuoi long nhifim Saprolegnia sp.
-Nam Saprol^nia sp. kysinh dci tam Sgi nam mau tring, chifiu dai khoang 2.900 - 5.200 pm, chifiu ngang khoang 25 - 33 pm, hinh dng CO phan nhanh (Hinh 4/^, khong co vach ngan, ti-fin diu SOI nim cd nhung tiii bao tii dai tir 45 - 70 pm, nam trfin 1 cudng dai thing diing (Hinh 4B, 4C), voi eac hinh thiic sinh san nhu sitih duong, sinh san vo ti'nh bang tlii bao tu kin va sinh san hiiu tinh.
Khuan lac nam Saprolegnia sp.
phan lap tii ca tam
Saprolegnia sp. tii ca tim^ (Soi tuoi)
Bao tur Saprolegnia sp. phan lap tOr ca t i m HiTjjjv4. N^m S^rrvJegnia ^ . ph&n 1 ^ tit ca t i m Saprolegnia la gidng nam bac thap, chii yeu ky
sinh va gay bfinh trfin cac ddi tugng thuy san nuoc nggt, thuong gap nhat la bfinh nam thuy mL Chiing CO the lam ung tning ca; lam ca ngiia ngay, ca vao cac vat the khac lam troc vay triy da, tao dieu kifin cho cac tac nhan khae xam nhap. Gidng Saprolegnia CO cau tao dang sgi dai, dfi bam vao vat chii; lai eo tdc do phat tnfin nhanh nfin rat nguy hiem cho ca bj nhifim. Bao tii nim Saprolegnia mang nhifiu luoi moc dai, nen rat thuan lgi cho vific dinh bam vao vat chii.
Nhimg trifiu ehiing ciia bfinh la trfin vay va da ciia ca xuat hifin nhimg cho co mau xam hoac mau tring.
Khi nhimg chd mau xam hoac tring nay phat trien rgng ra va nhifiu gidng nhu bdng thi d6 la liic benh dang phat trien manh Stueland (2009).
a \'ifit Nam, D5 Thi Hoa va cong su (2004) cho bifit, Saprolegnia sp. ga\" tac hai Idn cho nghfi nuoi trdng thiiy san nuoc nggt tir giai doan san xuit gidng dfin giai doan nuoi thuong pham. Cac loai ca nuoc nggt, baba, ech dfiu nhifim nam na\'. Miia vu phat bfinh thuong cd nhifit do khoang 18 - 25' C, day cung
la khoang nhiet do b nhung khu vue nuoi ca tam tai Lam Ddng.
Nam Aphanomyces sp. kysinh oca tim
Hinh 5. Aphanomy<xs sp. phan lap tir ca tam ao Soi nim phan nhanh, ciu tao da bao, tuy nhien, giua cac tfi bao khdng co vach ngan nen sgi nam 78 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 4/2019
KHOA HOC CdNG N G H |
gidng nhu mot te bao khdng Id, Aphanomyces thuoc nhdm nam bac thap. Duong kinh cua spi nam 7 - 1 2 pm, kich thudc bao hi khoang 3x8-9 pm.
Aphanomyces cung la gidng nam cd nhieu loai CO thi gay bfinh cho thuy san vi du A. irregularis gay bfinh eho ca tim Adriatic (Czeczuga etal., 2014) hay A znvarfansgay bfinh cho caldc (Saylor etal., 2010).
6 Vifit Nam, D6 Thi Hda va cgng su (2004) eho biet, Aphanomyces invadans cung la mot trong cac tac nhan gay bfinh la lofit. Tuy nhifin, trong nghifin ciiu nay, chi bit gap nam Aphanomyces sp. o ca nuoi ao voi ty lfi ca nhifim bfinh thap (5,6% -1/18 miu) d- ca tam Nga va 7,1% (1/14 miu) d ca tam nuoi long);
vi the, nim Saprolegnia sp. duoc chon de gay nhifim Ihuc nghifim xac dinh tac nhan.
3.2, K^t qua fhi nghifim cim nhifim nam Sapokgnia sp. Ifin ca t ^ Xiberi khde
Hinh 6. Ty 1§ c i bi bfinh (hinh i ^ v i ty lfi ch^t tich luy (hinh B) trong thi nghifim cim nhifim nim
Saprolegnea sp. Ifin ca tim khoe Ket qua thi nghifim cam nhifim nim Saprolegnia sp. Ifin ca tam Xiberi duoc trinh bay d hinh 6.
Ci sau khi cam nhifim hoat dgng binh thudng, ddn ngay thii 5 ca d cac nghifim thiic cam nhifim mat do 10^, 10^ bao tii/ml bit diu cd diu hifiu bi bfinh.
Dau tifin c i c6 hifin tugng boi lgi hdn loan, khong binh thudng, thich eg xat vao thanh bd, lam trdc vay h-ay da. Tai vi til triy xudc ti-fin than cd mau tring xam, sau do xuat hifin cac soi manh va phat trien din t h ^ h tiing bui nim ti-ing, mot dau sgi nim bam vao da cua ca, dau kia tu do ngoai moi trudng nude. Ty lfi ca bl bfinh b ngay thir 5 lan lugt la 10% va 25% tirong ling voi mat do tiem 10^ va 10^ bao tu/ml. Ty le ca hi bfinh tang dan theo thdi gian, ddn ngay thti 10, ty le ca bl bfinh b nghifim thiic cam nhifim 10^ bao tir/ml Ifin dfi'n 100%; nghifim thiic 10* bao tii/ml ed ty lfi ca hi benh b ngay thir 11 la 70% va duy tii nhu the den hfi't thdl gian thi nghifim. Ngay thir 6 sau khi cam
nhifim, ca d' nghifim thiic thi nghifim 10^ bao tii/ml bit diu bi chet; ngay thii 8 sau cam nhifim, ty lfi chdt d' nghifim thiie 10^ bao hi/ml la 10% va nghifim thue W bao tii/ml la 5%. Den ngay thti 10 ty lfi chet tich luy d nghiem thiie 10* va 10^ bao tii/ml lin lupt la 50% va 80%. Ty lfi dd giu nguyfin cho den ngay thii 12 cua thi nghifim.
O nghifim thiic ndng do tiem 10^ bao tii/ml ca co dau hieu cua bfinh nam d ngay thii 9 cua thi nghifim.
Tuy nhien, ty lfi ca bi bfinh rat thap (5% d ngay thii 9 va dat cao nhat d ngay thti 10 voi ty lfi 10%). Ca b nghifim thtic nay khong bi chet. Ca d nghiem thiie ddi ehiing binh thirdng, khong ed dau hifiu bfinh.
Bfinh do nam Saprolegnia da gay thifit hai Idn cho nghe nuoi trdng thiiy san d nhidu noi trfin the gioi. Tai Nhat Ban, mdi nam bfinh do nim nay gay ra lam thief hai tdi 50% sin lugng (tuong duong voi 40 trifiu USD) ddi vol nghfi nuoi ca chinh (Hatai, 1980).
Benh nim da gay ra nhirng tdn that kinh td nang ne eho nghe nuoi ea hdi d Na-Uy va nhieu qude gia khac (Stiieland, 2009). Khong chi gay thifit hai cho ca nuoi thuong pham, nam Saprolegnia ciing gSy ung tiling va gay bfinh ca hdi giong b Na-uy, Canada, Chile, Scotland (Barnes etal, 1998), tham chi gay bfinh vdi ca ca hdi ngoai tir nhifin (Steckler et al, 2014).
Stiieland (2009) cho biet cae ehung nim Saprolegnia khac nhau thi kha nang gay bfinh va ti lfi chdt d ea hi nhifim bfinh khac nhau. Su khac bifit ve kha nang gay benh gitia cac chiing Saprolegnia duoc the hifin thong qua d lfi chef cua ea hoi thay dot tii 0 den 89%
khi hi nhifim. Athanassopoulou et al (2004) thong bao nim Saprolegnia sp. gay bfinh cho ca tim Nga, tuy nhifin ket qua cho thay ty lfi nhifim bfinh chi d miic 5% va cudng do nhifim d miie nhe.
4. KFT LUAN
- Da phan lap, xac dinh duoc nim Saprolegnia sp. va Aphanomyces sp. d ca 2 loai ca tim Nga va ea tim Xiberi nuoi thuong phim d Lam Ddng.
- Saprolegnia sp. la tac nhan gay bfinh nam cho catam Xiberi.
TAI UBITHAM KHAO
1. Vo Thfi Dung, Vo Thi Dung, 2018. Thanh phin va miic do nhifim ky smh tiling d ca tim Nga (Acipencer guldenstaedtii Brandt and Ratzeburge, 1833) va ea tim Xiberi (Acipencer baeri Brandt, 1869) nuoi ao va nuoi ldng tai U m Ddng. Tap ehi Khoa hgc va Cong nghfi Thuy san, Sd 3/2018: 26-31.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 4/2019 79
KHOA HOC CdNG N G H | 2. Vo The Dong, Vo Thi Dung, 2016. Nghifin
ciiu bfinh xuat huyet trfin ca tim Nga gidng (Acipenser guldenstaedtiii tai Lam Ddng va de xuit bifin phap phong tri. Tap chi Nong nghifip va Phat trien nong thon, Sd 5/2016: 87-91.
3. Vo The Dung, Vo Thi Dung, 2014. Ket qua nghifin ciiu benh xuat huyet, Id loet do vi khuin giy ra d ca tam nuoi thuong phim tai Lam Ddng. Tap chi Nong nghifip va Phat trien Nong thon, sd 23/2014:
99-105.
4. Vo The Dung, Vo Thi Dung, Glenn Allan Brisfovir, 2014. Bfinh do vi khuan gay ra d ci tim thuong pham tai Lam Ddng. Tuyen tap Hgi thio qudc te "Hop tac khoa hgc cong nghe va phat trien ben viing nong nghiep Lam Ddng - Tay Nguyfin 2014. Trang 117-122.
5. Vo The Dung, Nguyfin Viit Thuy, 2013. Nuoi ca nude lanh tinh Lam Dong - Thanh tuu va trien vong. Tuyen tap Hoi thao qudc tfi khoa hoc va cong nghe phue vu phat tridn sin xuat nong nghiep cong nghe eao tinh Lam Ddng, Da Lat, 29/3/2013. Trang 78-81.
6. Vo The Dung va Trin Thi Bach Duong, 2011.
Nghifin ciiu tie nhan gay bfinh trfin c i tim (Acipencer baerl) vk ca hdi (Oncorhynchus mykiss) trong hfi thdng ao nuoi cong nghiep. In trong. Ky yeu Hoi nghi khoa hgc thuy san toan qudc, ngay 16/12/2011, Trudng Dai hge Nong Lam thanh phd Ho Chi Mmh, 196-200.
7. Vo The Dung, Vo Thi Dung, Nguyfin Thi Hdng Tuyen, Nguyfin Viet Thiiy, Le Phudc Thuan, 2011. Nghifin ctru mgt sd tic nhan ed kha nang gay bfinh xuat huyet Id lofit b ca tim (Acipenser gueldenstaidth va A. baeri) nuoi d Lam Ddng. Tap ehi Nong nghifip va Phat hien nong thon, Sd 23/2011:74-79.
8. Dd Thi Hda, Bin Quang Te, Nguyfin Huu Dung va Nguyfin Thi Muoi, 2004. Bfinh hgc thuy san, NXB Nong nghifip, TP. Hd Chi Minh.
9. Athanassopoulou P., Bilhnis C, and Prapas Th., 2004. Important disease conditions of newly cultured species in mtensive freshwater farms in Greece: first ineedence of nodavirus mfeetions m Acipenser sp. Diseases of Aquatic Organisms, 60:
247-252.
10. Barnes M. E., Ewmg D. E., Cordes R. J. and Young G. L., 1998. Observations on Hydrogen Peroxide Conti-ol of Saprolegnia spp. during Rainbow Trout Egg hicubahon. The Progressive Fish- Cultinist, 60(1): 67-70.
11. Bauer 0 . N., Pugachev 0 . N. and Voronin V N., 2002. Stiidy of parasites and diseases of sturgeons in Russia: a review. Journal of Apphed Ichthyology, 18: 420-429.
12. Czeczuga B., Czeczuga-Suneniuk E., Sarosiek N. and Simeniuk A., 2014. Hamful effects of the sti-aminipiles organisms on the reproduction of the Adriatic stiirgeon. Current Trends in Microbiology, 9: 57-64.
13. Hatai K., 1980. Stiidies on pathogenic agents of saprolegniasis m fresh water fishes. Special Report of Nagasaki Prefectural Institute of Fisheries No.8, Matsugaecho, Nagasaki, Japan.
14. Hatai K., Egusa S., Takahashi S. and Ooe K, 1977. Stiidy on the pathogenic fiingus of mycotic granulomatosis -1. Isolation and pathogenicity of the fungus from cultured-ayu infected with the disease.
Fish Pathology, 12:129-133.
15. Saylor R K., MiUer D. L., Vandersea M. W., Bevelhimer M. S., Schofield P. J., Benneti: W. A, 2010. Epizootic ulcerative syndrome caused by Aphanomyces invadans in captive bullseye snakehead Channa maruhus collected from south Flonda, USA. Dis. Aquat. Org., 88:169-175.
16. Steckler N. K., Yanong R P. E., Pouder D.
B., Nyaoke A., Sutton D. A., lindner J. R, Wickes B.
L, Frasea 8. Jr., Wolf J. C, Waltzek T. B., 2014. New disease records for hatchery-reared sturgeon. II.
Phaeohyphomycosis due to Veronaea botryose. Dis.
Aquat. Org., I l l : 229-238.
17. Stueland S., 2009. Saprolegnia infection in salmonids: Characterization of Saprolegnia species and search for new treatment of Saprolegnia mfeetions. Thesis for the degree of Philosophiae Doctor. Norwegian School of Veterinary Science.
18. Willoughby L G., 1994. Fungi and Fish Diseases.
Hsces Press, Stirling, Scotland. 57 p.
80 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 4/2019
KHOA HOC CdNG NGHE
FUNGY DISEASES OF GROWTH - OUT RUSSIAN STURGEON (Acipencerguldenstaedtii Brandt and Ratzeburg, 1833) AND SIBERIAN STURGEON (Acipencer baerii Brandt, 1869) IN
LAMDONG PROVINCE
Vo The Dung, Vo Thi Dung Summary
The study on fungy eompositon and fungy that caused diseases for grow-out Russian sturgeon and Siberian sturgeon in Lam Dong province. A total of 128 specimens, including 58 sturgeon specimens with fungi disease signs (including 30 Russian sturgeon specimens and 28 Sibenan sturgeon specimens) and 70 healthy Siberian specimens were used for fungi disease study. Results showed that, mucus losses, ukerativeness, gill rot are fungi diseases of cultured sturgeon. Saprolegnia sp. and Aphanomyces sp., were isolated. The prevalences of pond and cage Russian sturgeon infected with Saprolegnia sp. were 22.2 % and 16.7%, respectively. The prevalences of of pond and cage Siberian sturgeon infected with Saprolegnia sp.
were 35.7% and 21.4%, respectively. Tbe prevalences of pond Russian and Siberian sturgeon infected with Aphanomyces sp. 5.6% and 7.1%, respectively; Aphanomyces sp. was not found on cage-cultured fish. Results of back-infected experiment showed that Saprolegnia sp. is the disease causing agent of Siberian sturgeon.
Keywords: Fungi disease, Russian sturgeon, Sibenan sturgeon, Lam Dong.
Ngudi phan bi$n: TS. Hii Ky Ngjly nhan bai: 12/02/2019 Ngiy thdng qua phan bifin: 12/3/2019 Ngiy duyfit dang: 19/3/2019
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 4/2019
