NGfflEN Cifu BIEN DONG SO L U O N G ROTIFER VA COPEPODA TRONG CAC AO NUOI SINH KHOI
TAI QUY KIM - HAI PHONG
Tg ThiHgnh Viin Sinh Nong Email: [email protected]
Ngdy nhdn bdi: 2/4/2018 Ngdy PB ddnh gid: 24/4/2018 Ngdy duy4t ddng: 27/4/2018
TOM TAT
Rotifer va Copepoda Id thiic an tuai sdng dupe diing chii ydu cho uong nudi giai doan ddu ciia du tning ca bien. Hien nay, nhting ddi tupng ndy chi ed the nudi trong be dung tieh nhd vd nudi rieng tirng ddi tuang voi ehi phi tdn kem va ty Id sdng thdp. Trong khi dd, viec nudi ehung trong ao nudi de dang va chi phi thap bang vide sir dyng cac che dp gay mdu khde nhau chua van chua dupe nghien ciiu cy the. Ket qua nghien ciiu eho thdy, ao nudi sinh khdi rotifer dat mat do cyc dai d ngay nudi 5-6, ao nudi smh khdi copepoda dat mJlt dd cyc dai d ngdy nudi 11-13. Ao gdy radu bang ca tap cd mat dp rotifer vd copepoda eye dai cao ban so vdi ao gdy mdu bdn phdn vi sinh va ao gdy mdu sir dyng bpt cd ket hpp cam gao.
Tie khda: Ddng vdt phu du, luan tning, ca tap, phdn vi sinh, bpt ea, bpt cam gao.
RESEARCHING THE QUANTITY FLUCTUATIONS OF ROTIFER AND COPEPADA IN BIOMASS POND IN QUY KIM - HAI PHONG
ABSTRACT
Rotifer and Copepod are living food that is primarily used for rearing of marine fish larvae at the early stage. At present, they can only be raised in small tanks and individually raised with high cost and low survival rates. Meanwhile, eulturing thera in ponds with easy raethod and low cost using the different techniques in coloring water has not been studied in details. Results ofthe research showed that the biomass pond of rotifer reached the maximum density at the days 5-6, and the the biomass pond of copepod reached the maxiraura density at the days 11-13. The pond whose water colored by trash-fish had higher maxiraura density of rotifer and copepod than the one using biofertilizer and the one using fish meal combined with rice bran.
Tu khda: Zooplankton, rotifer, trash-fish, raicroorganic fertilizer, fish meal, rice bran.
T^P CHI KHOA HOC, So 28, thang 5/2018 I 45
1. M d DAU
Rotifer (Luan trirng) vd Copepoda la thiie an tuoi sdng cd nhieu uu didra dupe dimg chil yeu cho uong nudi du tning cd bidn. Chiing la dang con mdi sdng, cd tdc dp sinh san nhanh, kich thudc nhd, giau dinh duong, bd sung cac axit amin khdng thay the nen rdt phii hpp cho uong nudi au trung tdra, cd. Khu vyc Quy Kim - Hai Phdng cd nghe uong nudi ca bien rat phat trien dap ting nhu cdu con gidng cho nhirng tinh ldn can, ngudn thire an cho uong cd phu thupc nhieu vao ddng vdt phii du ngoai ty nhien.
Bai bao nay se danh gid loai thiic an ty nhien eung nhu thdi gian, chu ki phat trien dat mat dp eao ciia Rotifer va Copepoda trong dieu kien vdi che do cham sdc khac nhau, tir dd lam ca sd khoa hoc giiip nhirng nha nudi ca bien cd the chu ddng thu ngudn thirc an khi chiing dat mat dp cao nhdt de dap ung dii ngudn thirc an tuoi sdng phuc vy uong nudi ca bien mdt each hieu qud nhdt.
2. DOI TlTi^fNG VA FHU'CfiVG PHAP NGHlfiN CUtJ
2.1. Doi tuong va dia diem nghien ciru - Ddi tupng nghien ciru: Mdt sd loai ddng vdt phil du (Rotifer va Copepoda) trong ao nudc lp.
- Dia diera nghien ciiu: Tram nghien ciru NTTS nudc Ip - Quy Kim - Hdi Phdng
2.2. Vdt lieu va phuong phap nghien ciru 2.2.1. Di^ng cu thi nghiem
- Gdm cac ao hinh chir nhat, raoi ao cd dien tich la lOOOm^ coc dong, xd, ca, lp dyng mau, vpt lpe va ehau.
- Dyng cu thu mdu: Ludi hmh ndn, dai dudng kinh mieng ludi 20cra, chieu cao ludi 40 - 50cm, CO mdt ludi 50pm.
Kinh hidn vi, budng dem ddng vat phii du, ddng hd dem, nhiet ke, khiic xa ke, mdy do pH ...
- Dyng cy giai phdu: kim gidi phdu, panh, hop long, ...
- Cac hod chdt: formanme, hod chdt mdi tiirdng nudi cdy tao...
2.2.2. Vgt lieu nghien cieu
Thirc an su dyng trong thi nghiem bao gom: phdn vi sinh, cd tap, bdt ca ket hpp cam gao.
+ Ca tap: Ngudn cd tap dupe mua tut cac tau ddnh cd, ca mua ve dupe riia sach, ndu chin, sau do cd dupe xay nhuydn va ii vdi 1,5 lit ehe pham Super vi sinh. Khi sir dung boa vdi nude nudc tat deu khap ao. Mdi ao thi nghiem dung 10kg vd dupe chia Idm 2 lan trong sudt qua trinh thi nghiem. Thi nghi?m lap lai 3 lan vdi sd lupng cd su dung la 30 kg/3 ao tbi nghiera.
+ Phdn vi sinh: san phdra phan vi sinh diing lam nguyen lieu tdt nhdt nhd qud trinh len men tir dich the vi sinh vdt tao thanh, bao gdm nhieu loai vi khuan nhd vd cd ich.
Thanh phdn ctia phan vi sinh gdm: N, P, K, nguyen td vi lupng vd cac loai vi sinh vdt hmi ich. Sdn phdm phan vi sinh cd xudt xii tir Tmng Qudc dupe ddng bao vdi lidu lupng 2,5 kg/tiii. Tae dung cua phdn vi sinh: lam eho cae loai tao dan bdo trong ao phat trien manh va tao radi trudng nudc cd chdt lupng tdt. Khi sir dung hod vao nudc, sau dd cung cap deu khap cae ao thi nghiera. Mdi ldn thi nghiem sti dung 5 gdi vdi ham lupng la 10kg ehia ldra 2 Ian trong qua trinh thi nghiera. Thi
46 T R I T Q N G D A I H O C HAI PHONG
ngbiep lap 3 Idn vdi lieu lupng sii dyng la 30kg/3 ao thi nghiem.
+ Bdt ea ket hop cam gao hod ciing 401 nudc, sau do u vdi 1,51 ehe phdm Siqier vi sinh.
Khi sii dung khuay deu va tat lahap xung quanh ao. Lieu lupng sii dung la lOkg vd chia lam 2 Ian. Thi nghiera lap Iai 3 lan vdi hdu lupng su dung la 30k^3ao thi nghiera
2.2.3. Phuangphdp bo tri thi nghiim Thi nghiem dupe tidn hdnh gdy mdu vdi 4 cdng thiic vdi 3 ldn lap eho radi edng thiie nhu sau: C T I : Sir dyng phan vi sinh
CT2: Sie dung cd lap
CT3: Su dung bgt ed kit hgp bdt cdm gao CT4: Thi nghiim doi chung (de ldo phdt triin ti^e nhiin trong ao)
- Thi nghiem dupe bo tri trong 12 ao theo so dd khdi ngdu nhien hodn toan. Mat dp dpng vdt phil du ban ddu theo ngudn nudc. Cac che dp eham sdc vd qudn Iy duy tri nhu nhau.
Tien hanh thu mdu xac dinh thanh phdn gidng loai ddng vdt phu du trong ao.
Thdi gian thu mau tir 6h sang den 7h sang tiong ngay
- Vi tri thu mdu: Dimg vot ed kich thude mdt ludi 50 pm keo lpc ddng vdt phu du d nhieu diem khdc nhau tiong radi ao thi nghiem.
- Xu li mau: mdu djnh lupng dupe xir li bdo quan trong dung djch Formanine 3 - 4%
- Phan tich mdu: Trudc khi phan tich radu phai lac nhe mdu de ddng vat phu du phdn bd deu sau dd diing dng hiit Idy 3 Idn/mdu, mdi ldn Idy 1 ml. Mdu dupe dua vao budng dera vd quan sat tren kinh hien vi. Neu mat dp qud ddy thi boa loang ra dem. Xac dinh mat dp dpng vdt phii du bang phuang
phap ddm ca thd ciia Konvic, 1905. Dung budng dem dyng mau vd dem cac ca the dpng vdt phil du dudi kinh bien vi.
- Mat dp ddng vat phu du dupe xac dinh theo cdng thiic tinh sau:
AxC
Trong do A : lupng nudc lpc (lit) B : lupng nude ed dae(ral) C : the tich nudc dera dera (ml) D : sd ea the dem dupe
- Tinh mat dp tnmg binh cua Copepoda vd Rotifer bang edng thiic:
1
D = X ( D i + D 2 + ..Dn) n
D: mat dp ca the trung binh Dn: mat dp ca the dem dupe d ldn ddm thic n
n : sd ldn dem
- Cdng thirc xac dinh ty Ie % cac thdnh phdn trong rapt raau
Trong dd fi : Ty Id % lodi i dupe xdc dinh trong mdu tdng the
n,: Sd lupng ea the lodi i trong radu tdng the
N: Tdng sd ed the trong mdu phdn tieh 2.2.4. Xulysd lieu
- Su dung phdn mdm Excell 2003 dd tinh cdc gia tri tiimg binh, dp lech chudn, sai sd chudn va phuang sai.
TAP CHi KHOA HQC, S^ 28, thang 5/2018 47
- Ve cdc dd thi, bdng bieu the hien thanh phdn lodi vd mat dp theo tbdi gian va khdng gian.
Phdn tieh phuong sai 1 nhdn td (ANOVA) va sii dung tieu chudn LSDo,o5 dd xac dinh raiic dp sai khac giiia cae cdng thiic thi nghiem. Cac phdn tich tbdng kd dupe sir dung vdi dp tin eay 95% (a=0,05).
3. KET QUA NGHIEN CUtI 3.1. Kdt qua bidn dong so luong rotifer trong cac ao nudi sinh khoi
Qua trinh phdt tridn ban ddu Id sy phat tridn ciia cdc qudn the luan trung Brachionus plicatilis keo ddi hem 10 ngay va tidp sau do den sy phat trien eua quan the Copepoda cho den hon 20 ngay. Kdt qud thi nghiem bien ddng qudn thd ludn tiling ti-ong eae edng thtic gay mau dupe the hien qua dd thi sau:
ede tning nghi cdn sdng sdt Iai dudi day ao.
Khi nhiet dp trong ao d khoang 30 C thi so lupng luan trimg bat ddu tang nhanh vd dsit cyc dai tirong vdng tii 5-7 ngay sau khi ao dupe cap nudc. Kdt qua nghien ciiu cua Dhert (1995) vd thai gian trai qua giai doan smh san cao nhdt cting chi mot vdi ngay. Vdi kdt qua thu dupe tirong thi nghiem eho thdy, thdi gian dat mat dp cyc dai dai hon la do mat dp ludn tning ban ddu thap, cdc cd the edn cd thdi gian dd thich nghi trong didu kien nudi, sau dd phat trien va dat mat dp cyc dai.
Vdi kdt qud thu dupe ti-ong thi nghiem nay tbi thdi gian thu hoach luan trung vdo ngay thii 6 eiia chu ki nudi.
Bang 3.1. Mat dp cue dai ciia Rotifer trong cac cong thiie khac nhau.
Hinh 3.1. Biin dgng mat do trung binh cua rotifer trong cdc cdng thue
CO che do gdy mdu
Dudng cong bieu dien sy sinh trudng eua qudn the ludn tning thudc loai Brachionus plicatilis, sd lupng ludn trimg tdng len nhanh chdng va dat cyc dai tai ngdy thii 5-6 eiia chu ky nudi sang ngay 7- 8 mat dp ludn triing bat dau suy gidm nhanh. Theo ket qua nghien ciru cua Gerald M. & et al (1998) ludn tning Id nhdm ddng vdt phii du phat trien ddu tien trong ao, chiing nd ra tir
Cong thuc gay mau CTI CT2 CT3 CT4
MDLuan trungCD (ct/1) 2.152 ± 8 3 "
10.287 ± 835' 4.917 ±289°
222 ± IS""
Sd lieu trinh bdy Id gia tri tnmg binh ± sai sd chudn (SE). Sd lieu trong eiing mdt cot cd ky hieu sd mu a, b, e, d khdc nhau minh hpa cho khac biet cd y nghTa ve mat thdng ke (aK),05).
Kdt qua nghien eim tir hinh 3.1 va bang 3.1 cho thay mat dp luan tning dat cao nhat trong ao nudi cd sir dung cd tap xay nguyen (CT2) Id 10.287 cd thd/1, tidp sau dd la ao nudi sir dung hot ed ket hpp cdm gao (CT3) la 4.917 ea thd/1; phan vi sinh (CTI) Id 2.152 ca thd/1 va thdp nhdt la trong ao nudi khdng cd bd sung chat gay mau Id 222 ca the/1; mat
48 TRirdNG DAI HQC HAI PHONG
dp cya d^i giiia eac cdng thiie deu cd sy sai khde cd y nghTa thdng ke (a=0,05).
Cdc ket qua cho thdy, cdng thiic sii dung ca tap cho mat dp cyc dai cao hon cdc cdng thiie cdn Iai, dieu nay cd the gidi thich bdi cd tap raua tir tau edn tuoi duoc xay nhuyen ndu chin thi ham luprng dinh duang cdn nguyen ven khi bd sung xudng ao nudi se kich thich su gia tang sd lupng thyc vdt phil du. Sy gia tang sd lupng thyc vat phii du gpi Id hien tupng nd hoa, thyc vdt phii du tang la ngudn thiic an tryc tiep cho ddng vat phii du. Mat khae, cd tap xay nhuyen kich thudc nhd, mui vi hdp dan nen cd the duoc hdp thu tryc tiep bdi cac ddng vdt phii du nhu vay se ldra tdng sd lupng nhanh ehdng khi sti dung. Cdn hot ca ket hpp cam gao cd kich thudc nhd hda dang nudc dupe ngudi nudi thudng sir dyng de cdi thien mdi trudng ao nudi hoac gdy mau kich thich sy phat tridn thyc v^t phii du. Tuy nhien, bdt cd da qua phoi khd va xir li nen ham lupng dinh duong gidm hon Iiic tuoi va raiii vj khdng hdp ddn nhu ca tuoi nen hieu qud khong cao bang cd tuoi xay nhuyen.
Vdi ket qua nghien ciru ndy, chiing tdi eiing chua tira dupe ddn chiing khoa hpc eua tdc gia nao ve mat dp eye dai thu dupe khi sir dung phan vi sinh, ca tap xay nhuyen, bdt ca de gay mau.
3.2. Ket qua bien dong s6 luong Copepoda trong cac ao nuoi sinh khoi
Ben canh sy phdt trien ciia Rotifer thi cimg Ihdy sy phat tridn cua qudn the Copepoda ngay tu nhiing ngay ddu khi ludn trimg bat dau phat trien vd chu ki phdt trien theo ddi trong thi nghiera ctia qudn the Copepoda Id hon 20 ngdy.
Ket qua thi nghidm bien ddng qudn the Copepoda trong cdc cdng thtic gay mau dupe the hien qua dd thi sau:
Hinh 3.2. Bien ddng mat do trung binh ciia Copepoda trong cdc eong thiec
CO chi do gdy mdu
Hinh 3.2. bieu dien sy sinh trudng ciia quan the Copepoda, cung vdi sy phat trien ciia ludn tning, qudn the Copepoda cung bat ddu tang ve mat sd lupng. Mat dp Copepod d mdu thu ngay ddu tien 27 ed the/lit, ede cd the tdn tai d cdc giai doan khac nhau trong vdng ddi. Tai cdc thdi diera khac nhau chiing cd tdc dp tang trudng khac nhau vd mat dp cung khae nhau. Nhiing ngdy ddu, qudn the Copepod phdt trien vdi tdc dp chdm, tir ngay thti 9 trd di cac ca the phat trien nhanh vd dat mat dp cyc dai tu ngay thii 10 den ngay thii 13. Giai doan suy gidm mat dp quan the tir ngdy thii 18 trd di mat dp cd sy suy gidm nhanh chdng, tuy nhien mdt sd ed the thich nghi khdng bi tieu diet het trong mdi trudng ma van tdn tai vdi mat dp thdp.
Theo Gerald M. & et al (1998) cho rang, rotifer phat trien sau mdt vdi ngay sd luong ctia chiing gidra xudng thdp. Khi sd lupng rotifer gidm xudng thi Nauplius ciia Copepoda bat ddu tang. Nauplius cd kich CO nhd va chiing thudng dat mat dp eao sau khoang 2 den 3 tuan sau khi bdn phdn gdy mdu.
TAP CHI KHOA HQC, So 28, thang 5/2018 49
Cung theo Geiger&Turner (1990) tir nhiing ngdy ddu khi cdp nude vao ao cho ddn ngay thii 6 thi toe dp gia tang sd lupng cd thd cham. Sd lupng tang trudng chdm cd thd do mdt sd nguyen nhdn co ban la sd lupng ddng vdt phu du trong ngudn nudc thdp vd ludn trimg Id nhdm cd vdng ddi ngdn, sinh san nhanh dd ehiem uu the va da nhanh ehdng dat mat dp cyc dai. Copepoda cd hinh thuc sinh san hiru tinh cdn thdi dai hon dd tang so lupng cd the trong qudn the ciia chiing.
Nhu vay, quy luat phdt trien vd thdi gian phat tridn ciia rotifer va copepoda trong thi nghiem ciing gdn phii hpp vdi nghien ciiu eua tac gid. Vdi kdt qua thu dupe trong thi nghiera nay thi thdi gian thu hoach Copepoda tir ngdy nudi thii 10 den ngay nudi thir 13 eua chu ki nudi.
Bang 3.2. Mat dp cue dai cua Copepoda trong cac cong thiic khac nhau.
Cong thuc gay mau
CTI CT2 CT3 CT4
MSCopepodaCD(ct/l) 683 ± 20"
1.523 ±29'"
1.396 ± 4 2 ' 232 ± 1 8 "
So Heu trinh bdy la gid trj trung binh ± sai so chuan (SE). Sd lieu trong cting mdt cot cd ky hieu sd mu a, b, c, d khac nhau minh hpa cho khae biet cd y nghia ve mat thdng ke (a=0,05).
Ket qua nghien cirutii hinh 3.2 vabang 3.2 eho thdy mat dp Copepoda dat cao nhdt
trong ao nudi ed sir dung cd tap xay nhuyin (CT2) la 1.523cd tbd/I, tidp sau do la ao nudi sii dung bdt cd kdt hop cam gao (CT3) la 1.396 ca thd/1; phan vi sinh (CTI) la 683 ca thd/1 va thap nhdt Id drong ao nudi khdng co bd sung ehdt gay radu la 232 ea the/1; mat dO eye dai giiia ede edng thirc deu cd sy sai khac cd y nghTa tbdng ke (a=0,05).
Cdc kdt qua eho thdy, cdng thirc sii dyng ca tap cho mat dO eye dai ciia cd rotifer va copepoda cao hon cac edng thirc cdn Ijii.
Tuy nhien, vdi kdt qud nghien ciiu nay, ehung tdi ciing chua tim dupe dan chiing khoa hpe ciia tdc gia nao ve mat dp eye dai thu dupe khi sii dung phan vi sinh, ed tap xay nhuydn de gay radu.
4. K E T LUAN
- Thdi gian dat radt dp cyc dai luan triing (Brachionus plicatilis) a ngdy nudi thii 5 - 6 vd cdng thuc sir dung ca tap xay nhuyen cho hieu qua nhat vdi mat dp luan trimg cao nhdt (CT2) la 10.287 cd thd/1, tifip sau do Id ao nudi sir dtong bdt ca ket hop cara gao (CT3) Id 4.917 ca thd/1; phan vi sinh (CTI) la 2.152 ed thd/1 va thdp nhdt la trong ao nudi khdng cd bd sung chat gay mau la 222 ca the/1.
- Trong cdc cdng thiie ed che do cham bdn khac nhau ngay nudi thii 1 0 - 1 3 qudn the copepoda dat mat dp cyc dai, cong thiic sir dung ca tap (CT2) Id eho hieu qua nhat vdi mat dp Copepoda cyc dai la 1.523; tiep theo do Id ao nudi sii dung hot ca ket hop cam gao (CT3) la 1.396 cd thd/1; phdn vi sinh (CTI) Id 683 ca tbd/1 va thdp nhat Id ti-ong ao nudi khdng cd bd sung chat gdy mau la 232 ca the/1.
50 I TRirdNG DAI HQC HAI PHONG
T A I LIEU THAM KHAO
1. Dang Ngpc Thanh (1980), fJinA logi dgng vdl khong xuang sdng nu&c nggt bdc Viet Nam.
Nha xudt ban Khoa hpc vd Ky thudt.
2. Dang Ngpc Thanh va Thdi Trdn Bai (1981), Dong vgt hgc khdng xuang song, Nha xuat bdn dai hpc va trung hpc chuyen ngbiep, Ha Ndi.
3. Nguydn Duong Thao (2002), 'Nghien eiiu mpt sd dae didm co ban ciia khu he DVPD (Zooplankton) la thirc an eho ed d viing bien mien Nam Viet Nam', Lugn dn tiin si sinh hgc, Vien nghidn ciiu Hai san - Hai Phdng.
4. Tai lieu ky thuat nghe ea cua FAO (2002), Cdm nang sdn xudt vd su dung thirc dn song di nudi thuy sdn, Bd Thuy sdn Viet Nam, Ha Ndi, 49-75.
5. Hodng Thi Ty (1999), 'Dieu tra thanh phdn Ioai va bien ddng sd lupng cd the dpng vat phu du d mdt sd thuy vye tinh Bdc Giang', Lugn vdn Thac sy ngdnh Nudi trong Thuy sdn, Trudng Dai hpc Thuy sdn, Nha Trang.
6. Gerald M. & et al (1998), Fertihzation of Fish Fry Ponds,Southern Regional Aquaculture Center from the United States Department of Agriculture, Cooperative States Research, Education and Extension Service, page:8.
TAP CHI KHOA HQC, S6 28, thang 5/2018 51
