Tap chi Khoa hoc va Cong nghe bien T9 (2009). So 2. Tr 64 - 70
ANH HUOTVG CUA CAC LOAI THlTC AN KHAC NHAU LEN 81/ SINH TRUOTVG VA TI LE SONG CUA CA NGlfA VAN
(HIPPOCAMPUS COMES, 1850) NUOI THUTOfNG P H A M
TRUONG Si KS *". HO THj HO.V", HO.ANG DVC LU^", PHAM VU LANC'^'
Tom tat: Ndi dung eua bdi viel ndy Id trinh bay nhmig ket qua nghien ci'ru anh hirtrng cua Mysis, Aceies vd ket hap ca hai loai time an ndy len sir tdng truang vd ti le sdng cua cd ngira Van Kel qua cho thd\ rdng khdng cd sir sai khdc ve chieu cao vd khdi lircrng eua ca ngua dn Mysis vd Acetes (P 0.05). nhung chieu cao cua cd dn ket hap hai loai thuc dn noi tren Id cao nhdt (P 0.05).
Ti le sdng cua cd ngira a tdt ca cdc Id thi nghiem deu cao han 97%,. Co the ket ludn rdng Mvsis vd .Acetes ddng lanh Id tliirc dn thich hop cho cd ngua. Chung co san trong dieu kien lir nhien a bien I iet .\am. nhung xuat hien theo mua vu. vi the cdn mua vd cap ddng cdc loai thuc dn ndy de su dung cho nudi cd ngira trong ca nam. .Icetes vd Mysis cd the thay the cho thuc dn Id .Anemia sdng vd gidu hda de nudi cd ngira trong thai gian trudc day.
I. MO DAU \
Ca ngua Van hay cdn ggi la ca ngira dudi I Id (Tiger tail seahorse) la loai phan bd d viing bien nhiet ddi Phai Binh Duang, chiing thudng sdng d nhung viing cd ran san hd, do sau khdng qua 20m. O Vict Nam chi mdi phat hien loai nay d vimg bien Phu Yen va Khanh Hda (Lourie va cdng sir, 1999). Chung la ddi tugng khai thac cua nghe lan va dugc bay ban d dang sdng, phuc vu cho \ iec ngam rugu va lam thudc ddng y. Day la mot loai ca ngua qui hicm va ciing dang cd nguy ca bj de dga vi bj khai thac qua mire (Truong ST Ky. 1998).
Nghien cim ve dinh duong ddi vai ca ngira cd cdng trinh ciia Woods va Venlentino (2003),Woods (2005). Cac tac gia nay nghien cim anh hudng cua thirc an va khau phan an len su sinh trudng va ti le sdng cua loai //. abdoininalis. Mot sd tac gia khac (Truong ST Ky va cdng sir, 1996; Dd Hiru Hoang va cdng sir, 1998, 2001) nghien ciru thanh phan thirc an ciia ca ngira H. I<uda, H. spinosissiimts va //. tritnciculatus a ngoai tir nhien va cho rang chung thay ddi phd thirc an, ca nhd an ddng vat ndi. chii yeu la Copepoda, ca Idn an sinh vat day (Amphipoda, tdm Palaemonidae). Cho den nay chua cd cdng trinh nao nghien ciiru ve dinh dudng ca ngira Van (in situ va ex situ) tren The gidi eung nhu d nude ta.
Muc dich cua bai viet nay la xac dinh thanh phan thirc an thich hgp ciia ca ngua Van trong dieu kien nudi nhdt, de hoan thien qui trinh nudi thuong pham loai ca cd gia trj kinh te cao va qui biem nay.
II. PHU^ONG PHAP NGHIEN CLfU
Ca ngua dugc nudi trong be 60 lit (anh 1) vdi sd Iugng la 15 con. Thi nghiem dugc tiSn hanh trong he thdng Igc sinh hgc vdi hai loai thirc an la Mysis va Acetes ddng lanh, va ket hgp ca hai loai thirc an nay vdi ti le 50:50, ngay cho an 4 lan: 7 gid, I Igid, 13 gid va 16 gid. Liic ca cdn nhd thi Acetes dugc cat nhd, rira sach trudc khi eho an. Che dp cho an bao boa. Do dac cac yeu td mdi trudng, thay nude hang tuan va ve sinh hang ngay. Ca dugc can do chiSu cao va khdi Iugng djnh ky 15 - 20 ngay/lan. "Thi nghiem dugc lap lai ba lan va tien hanh trong thdi gian 3 thang vdi ea ciia the he Fl.
Cae thdng sd ciia mdi trudng nudi nhu sau:
Do mudi 30 - 35ppt Oxy 4-5 ppni pH 8-8.4 Ammonia Oppm Nitrite Oppm Nitrate < 20ppm
Tinh tdc do tang trudng dac trung (SGR) theo cdng thirc:
G = log W 2 - logWl/t2-tl
Diing phdn mem ANOVA de- danh gia sir sai khac cd y nghTa hay klidng ciia so lieu thi nghiem.
A_|£. 4
Anh 1. BC'cathi nghiem
HI. KET QUA NGHIEN CUtJ VA THAO LUAN
Nhu tren da trinh bay, thi nghiem dugc tien hanh vdi 2 loai thirc an: Acetes, Mysis va ket hgp hai loai thirc an nay. Ld 1 ca ngija dupe cho an Mysis, Id 2 thirc an la Acetes va Id 3 la ca hai loai thirc an nay vdi ty le 50:50. Ket qua dugc trinh bay d bang I, hinh 1 va 2. Cd the thay nudi ca ngua bang viec ket hgp 2 loai thirc an Mysis va Acetes cho ket qua tang trudng nhanh hon ea ve khdi Iugng lan chieu cao. neu so vdi ca an mdt loai thirc an la Acetes hay Mysis (P< 0,05). Dieu nay eung dung vdi tdc dp tang trudng dac trung ciia ca d cac Id thi nghiem. Tuy nhien, khdng cd su khac biet cd y nghTa giira chieu cao ca ngua an Mysis va Acetes (P>0,05), ti le sdng ciia ca ngua d tat ca cac Id thi nghiem deu cao hon 97%. Nhu vay. ngoai y nghTa ve mat khoa hpc. ket qua nghien cim nay cdn cd gia trj ve kinh te va giam gia thanh san xuat. Gia 1 kg Mysis tren thj trudng la 70.000 ddng. trong khi dd Acetes chi cd gia tir 15.000 - 20.000 ddng.
Bang 1. Anh hudng ciia thirc an len sir sinh trudng va ti le sdng ciia ca ngua Van nudi thuong pham
Chi tieu
Chieu cao ban dau (mm) Trang binh
Chieu cao cudi ciing (mm) Trang binh
Khoi lupng ban dau (g) Trung binh
Khdi lupng cudi ciing (g) Trung binh
SGR (Tang trudng dac trung)
Ti le sdng (%)
Mysis 78,60-79,86
79,08
99,2-103,00 92,20 1,51 -1,56
1,54 3,06-3,69
3,41 0,0087
100
Acetes 78,6-79,73
78,84
98,26- 104,26 90,45 1,52- 1,59
1,55 3,3-3,76
3,57 0,0091
100
Mysis va Acetes 77,60 - 79,20
78,84
1 0 4 , 7 3 - 108,85 94,20 1,43- 1,49
1,47 3,89-4,63
4,20 0,0114
97,78
120
110
70
60
10 20 - • — M y s i s
30 40
—»— Acetes
50 60 70
—*—Acetes + IVIysis
80 90 100 Thai gian (ngay)
Hinh 1. Su tang trudng cua ca ngua Vdn theo ehilu cao
10 20 30 40 50 60 70 80 90 100
-•—Mysis -»-Acetes -*—Acetes + Mysis Thai gian (ngay)
Hinh 2. Sir tanti trirdnc ciia ca nmra Van theo khdi luong
Giai thich siJ khac biet ve tdc do tang trudng ciia ca ngua Van ddi vdi cac loai thirc an khac nhau van cdn nhieu khd khan. Cho den nay chua cd mdt cdng trinh nao nghien ciru cho sinh san loai ca nay d tren The gidi (Foster va Vincent, 2004), do dd khdng cd tai lieu nao viet ve dinh dudng ciia loai ciia chiing trong dieu kien nudi nhdt. Tuy nhien, ddi vdi loai H. abdoininalis d NewZealand. cd cdng trinh nghien ciru ve dinh dudng do Woods va cdng sjj (2003) thirc hien. Ket qua thijr nghiem vdi 3 loai thirc an Mysis, Artemia giau hd^'va ket hgp ca hai loai nay cho tha)' khdng cd sir khac biet ve tang trudng cua ca ddi Vcri cac loai thirc an nay. Mac dii he sd ehuyen hda thirc an (FCR) ciia ca an Artemia giau hda (Enrichment) thap nhat (bang 2). Tac gia nay khdng giai thich vi sao ham Iugng DHA, EPA va ea protein cua Mysis cao hon rat nhieu so vdi Artemia (bang 3), nhirng ket qua tang trudng ciia ca ngua lai gidng nhau. O dieu kien Viet Nam, nudi sinh khdi Artemia trong be xi mang van cdn nhieu ban che, chi phi tdn kem, cho nen tinh kha thi nudi ca ngua bang loai thirc an nay la khdng hien thuc. Ngoai ra, de dap irng nhu cau dinh dudng cua ca ngua, can phai giau hda Artemia bang cac san pham chira nhieu HUFA nhu Seico (INVE, Belgium), se tang gia thanh san xuat va cdng lao ddng. Mysis va Acetes thirc an cd gia tri dinh dudng cao va cd san trong tu nhien, thich hgp cho viec nudi thuong pham ca ngua. Tuy nhien, hai loai thirc an nay chi xuat hien theo miia vu trong nam, cho nen de nudi ca ngua can phai mua chimg va cap ddng, de cho ca an trong ca nam.
Bang 2. Anh hudng ciia cac loai thirc an khac nhau len sir sinh trudng ciia ca ngua H. abdoininalis (Woods va Valentino, 2003)
Chieu dai ban dau (mm) Chieu dai cudi ciing (mm) KJioi luong ban dau (g) Khoi luong cuoi ciing (g) Ti le song (%)
FCR
Artemia 113,1 138,4 2,75 6,22 100 6,14
Mvsis 113,0 133,6 2,99 5,30 100 8,72
Artemia va Mvsis 114,6 135,8 3,03 5,62 100 6,9
Bang 3. Thanh phan hda hgc (%) ciia Artemia giau hda bang SeIco va Mysis (Woods va Valentino, 2003)
Protein Lipid Do am Tro
Artemia giau hoa 3,9 0.77 93,3 1,7
Mvsis 6,5 0,86 88,9 3,1
Ca ngua ngoai tu nhien chi an thirc an sdng va ehuyen ddng (Truong ST Ky, 2000), da> la trd ngai Idn trong viec phat trian nghe nuoi chiing, vi cac loai thirc an na\ deu khdng the nudi sinh khdi. Thanh cdng thuSn hda ca ngua an thirc an ddng lanh Mysis va Acetes md ra trien vgng nudi chiing trong cdng dong. Tuy nhien d6 bai bao nay thuylt pbi^ic hon, can cd nhung nghien cim sau v^ thanh pbSn HUFA va protein eiia cac loai thirc an ndi tren trong dieu kien ci,i thg d Viet Nam, d6 cd nhirng nhan .xet .\ac dang \k vai trd dinh dudng len sir tang trudng va ti le sdng ciia ca ngua.
TAI LIEU THAM KHAO
1. Do Huu Hoang, Truong Si Ky, Ho Thi Hoa.1998. Feeding behaviour and food of seahorse in Viet Nam.The Marine Biology of the South China sea. The third International Conference on the Marine Biology of the South China sea.307 - 321.
2. Do Hu'u Hoang, Tru-ong ST Ky. 2001. Anh hudng cua thirc an len sir tang trudng ciia ca ngua Den. Tuyen Tap bao cao khoa hgc. Hdi nghj biSn Ddng 2000. 481 - 498.
3. Foster S.J. & Vincent A.C. J. 2004. Life history and ecology of seahorses. The Fisheries Society of the British Isles, Journal offish Biology, 65, 1-61.
4. Lourie, S. A., Pritchard, J. C , Casey, S. P., Ky, T. S., Hall, H. J. & Vincent, A.
C. J. 1999. The taxonomy of Vietnam's exploited seahorses (family Syngnathidac).Biological Joumal of the Linnean Society 66, 231 256
5. Truong ST Ky, Nguyen Dinh Mao, Ton Nir My Nga, Do Hiru Hoang. 1996.
Ihimh phiiii thirc an va tap tinh dinh dudng cua hai loai ca ngua Ba chiim (Hippocampus trimaculatus) va ca ngua Gai (II. histrix) sdng d vimg bien Binh
Thuan. Tu\en tap Nghit-n Ciru BicMi . Tap VII: 163 - 170.
6. Truong SI Ky. 1998. Thanh phan loai ca ngua d bien Viet Nam. Tuyen tap Nghien CiruBi^n. Tap V I 1 I : I 5 4 - 165.
7. Tru-o'ng ST Ky. 2000. Ky thuat nudi ea ngua bien Viet Nam. Nha xuat ban Ndng nghiep.59 trang.
8. Woods Chris M C & Fiamnia Valentino. 2003. Frozen mysids as an altemative to live Artemia in eulturing seahorses Hippocampus abdominalis. Aquaeulture Research 34: 7 5 7 - 7 6 3 .
9 Woods Chris M C. 2005. Growth of cultured seahorse (Hippocampus abdominalis) in relation to feed ration. Aquaeulture intemational 13:305 - 314.
EFFECTS OF DIFFERENT KINDS OF FOOD ON THE GROWTH AND SURVIVAL RATE OF .\DI LT TIGER TAIL SEAHORSE
(HIPPOCAMPUS COMES, 1850)
T R U O N G SI KY'". HO T i l l H O A ' " , HOANG D U C LU'", PHAM \ U LANG'^'
Summary: This study examined the effects on the growth and survival rale of cultured tiger tail seahorse (Hippocampus comes) fed on .Mysis and Acetes and a combination of these foods. The results show that there are no significant difference in length and weight between
Ireatmenls of Mysis and Acetes. but length of seahorse fed on Acetes and Mysis combination is higher than that of another treatments (P <0,05).
Survival rate of seahorse for all treatments is higher than 97 ','/,. //; conclusion, this investigation has demonstrated effective use of frozen ,\lysis and .Acetes for seahorse (U/uaciilture. ,M\sis and Aceies are available in Vietnamese seawalers. but they seasonally occur, so slioulil huy and keep them in frozen condition and using for seahorse culture whole year. These foods can be used as an alternative to live enriched .Artemia. that fed seahoise in the past.
Ngdy nhan hdi: 24 - 2 - 2009 Dia chi: ''' Vien Hai duong hpc Ngudi nhan xet: TS. Nguyen Thj Thanh Thuy "'Sinh \ien cao hoc
