mortality, especially during long-d

mortality, especially during long-distance or high-density transportation
(Teo et al. 1989; Gomes et al. 2003).
Anesthetics are widely used before and during transport
to slow metabolism and reduce stress of fish (Harmon 2009;
Pramod et al. 2010). Anesthetics reduce the contractile force
of the ventricular myocardium and alter gill haemodynamics
(Hill et al. 2002) by depressing neuronal activity (Sp
¨
ath and
Schweickert 1977; Arnolds et al. 2002) and preventing plasma
cortisol elevation (Iversen et al. 2003). These neural and physiological
variations reduce fish activity and metabolic rate, thus
decreasing oxygen uptake and carbon dioxide and ammonia production
(Zhuang et al. 2009). Therefore, water quality does not
decline as rapidly during fish transport when some anesthetics
are added (Berka 1986; Park et al. 2009).
When anesthetics are used at proper doses, physical damage
may also be reduced because fish are calmer and less active.
Consequently, anesthetics generally reduce fish mortality
during transportation (Estudillo and Duray 2003; Pramod
et al. 2010). Somewhat paradoxically, anesthetics have also been
shown to cause an acute stress response immediately after sedation
(Trushenski et al. 2012; Zahl et al. 2012). During this
acute response, the stress hormone cortisol may increase, leading
to increased levels of glucose and lactate in the blood after
sedation. Compared with the levels of these chemicals that occur
after a fish is stressed by handling, the amounts released in
response to anesthesia are low (Zahl et al. 2012). Levels of cortisol,
glucose, and lactate in the blood return to normal within
6 h after sedation (Trushenski et al. 2012). A number of anesthetics,
including tricaine methanesulfonate (MS-222), benzocaine,
2-phenoxyethanol, quinaldine sulphate, metomidate, and
lidocaine have been used in juvenile fish transportation (Guo
et al. 1995; Park et al. 2009; Pramod et al. 2010). Among the
broad spectrum of anesthetics, MS-222 appears to be used most
frequently (Marking and Meyer 1985; Berka 1986). Clove oil
(major constituent eugenol: 2-methoxy-4-[2-propenyl] phenol),
is another common fish anesthetic due to its efficacy, affordability,
and short withdrawal period (Harper 2003). Although
many studies have assessed the effects of anesthetics on ornamental
fish transported in polyethylene bags (Teo et al. 1989;
Pramod et al. 2010) and on low-density transportation of cultivated
juvenile fish (Guo et al. 1995), the effects of anesthetics on
juvenile survival and water quality during high-density transport
in polyethylene bags are not well studied.
Redtail culter (or Mongolian culter) Culter mongolicus is an
important piscivorous fish in China, widely distributed in lakes,
rivers, reservoirs, and other freshwater bodies (CAS 1976). The
species is characterized by high price and high market potential
(Zhang 2008). However, its population has declined seriously
during recent decades, mainly due to overfishing, habitat destruction,
and water pollution (Zhang 2005; Ye 2007). To rebuild
the population, China’s Ministry of Agriculture initiated stock
enhancement programs in some lakes of the Yangtze River basin.
Furthermore, pond and cage farming of redtail culters has developed
rapidly, increasing the need for juvenile transportation.
However, high mortality has been observed during transport
for redtail culters (Xu et al. 2009). Our objective in this study
was to evaluate the effects of MS-222 and clove oil on survival
of redtail culter juveniles during transportation in polyethylene
bags. Furthermore, we monitored water quality parameters to
help define important mechanisms of anesthetic action.
METHODS
Experimental fish.—We obtained juvenile redtail culters
from Niushan Lake Fish Breeding Center, Wuhan, Hubei
Province, China. Juveniles were stocked in a cultivation pond
for 1 month prior to the experiment. They were fed a commercial
pelleted diet in the pond, but feeding was terminated 1 d before
the experiment. Juveniles were 41 d old when the experiment
began (mean ± SE: total length = 46.09 ± 0.91 mm, body
weight = 0.75 ± 0.04 g).
Anesthetics.—Two commercial anesthetics, MS-222 (Sigma
Chemicals, St. Louis, Missouri) and chemically pure clove oil
(Shanghai Feixiang Chemical Factory, Shanghai, China), were
used to lightly sedate the fish. Each anesthetic was tested at
three concentrations based on previous experience, MS-222 at
10, 20, and 40 mg/L of water and clove oil at 2, 5, and 10 mg/L.
Sodium bicarbonate was used in MS-222 solutions to adjust pH
to 7.0.
Experimental setup.—The experiment was conducted on 31
July 2010. Juveniles scoop-netted after being seined from the
pond were batch weighted and transferred to bags. Eighty-four
bags used in this experiment (7 treatments × 4 time samples
× 3 replicates). The clear plastic bags were 20 L (40 cm wide,
63 cm high) and were sealed to be airtight after adding 5 L of
water,15 L oxygen, the fish, and their anesthetic treatment dose.
Transport density was 50 g of fish/bag (average, 67 fish/bag) or
10 g of fish per 1 L of water (13 fish/L of water). This density was
based on actual transport practices and a previous experiment
to measure oxygen consumption of juveniles.
All the bags were put in a vehicle and transported for approximately
1 h to the laboratory of the Institute of Hydrobiology,
Chinese Academy of Sciences. Natural light was maintained
in the laboratory, and an air conditioner was used to maintain
the air temperature at 25
◦
C. The experiment lasted for 24 h,
and three bags from each treatment were examined at each 6-h
interval to assess water quality.
Transport water came from the cultivation pond: temperature
= 29
◦
C, dissolved oxygen (DO) = 6 mg/L, pH = 7.8,
conductivity = 325 µS/cm, ammonia = 0.47 mg/L). During the
experiment, DO (YSI Model 85 instrument, YSI Inc., Beijing,
China) and pH (YSI pH100) were measured immediately after
the bags were opened, and total ammonia was titrated within
6 h after the bags were opened. Total ammonia content was
determined by the Nessler reagent spectrophotometric method
(Huang et al. 1999). Concentration of un-ionized ammonia was
calculated by multiplying the total ammonia by the appropriate
conversion factor according to the measured water temperature

Hasil (Bahasa Indonesia) 1:

mortalitas, terutama selama jarak jauh atau transportasi high-density
(Teo et al 1989;.. Gomes et al 2003).
Anestesi banyak digunakan sebelum dan selama transportasi
untuk memperlambat metabolisme dan mengurangi stres ikan (Harmon 2009;
Pramod et al. 2010). Anestesi mengurangi kekuatan kontraktil
dari miokardium ventrikel dan mengubah Gill hemodinamik
(Hill et al, 2002.) dengan menekan aktivitas neuron (Sp
¨
Ath dan
Schweickert 1977;. Arnold et al, 2002) dan mencegah plasma
kortisol elevasi (Iversen et al 2003). . Ini saraf dan fisiologis
variasi mengurangi aktivitas sh fi dan tingkat metabolisme, sehingga
mengurangi penyerapan oksigen dan karbon dioksida dan produksi amonia
(Zhuang et al. 2009). Oleh karena itu, kualitas air tidak
menurun karena cepat selama ikan Transportasi ketika beberapa anestesi
ditambahkan (Berk, 1986;. Taman et al 2009).
Ketika anestesi digunakan pada dosis yang tepat, kerusakan fisik
juga dapat dikurangi karena ikan yang lebih tenang dan kurang aktif.
akibatnya, umumnya mengurangi tingkat kematian ikan anestesi fi
selama transportasi (Estudillo Duray dan 2003; Pramod
et al 2010.). Agak paradoks, anestesi juga telah
terbukti menyebabkan respon stres akut segera setelah sedasi
(Trushenski et al 2012;. Zahl et al, 2012.). Selama ini
respon akut, stres hormon kortisol akan meningkat, menyebabkan
peningkatan kadar glukosa dan laktat dalam darah setelah
sedasi tersebut. Dibandingkan dengan tingkat bahan kimia ini yang terjadi
setelah ikan ditekankan oleh penanganan, jumlah dirilis pada
respon terhadap anestesi yang rendah (Zahl et al., 2012). Tingkat kortisol,
glukosa, dan laktat dalam darah kembali normal dalam waktu
6 jam setelah sedasi yang (Trushenski et al., 2012). Sejumlah anestesi,
termasuk tricaine methanesulfonate (MS-222), benzocaine,
2-Fenoksietanol, quinaldine sulfat, metomidate, dan
lidocaine telah digunakan dalam fi remaja transportasi sh (Guo
et al, 1995;. Taman et al 2009;. Pramod et al . 2010). Di antara
spektrum yang luas dari anestesi, MS-222 tampaknya akan digunakan paling
sering (marking dan Meyer, 1985; Berka 1986). Cengkeh minyak
(eugenol konstituen utama: 2-metoksi-4- [2-propenil] fenol),
adalah anestesi umum lainnya karena ef ikan fi khasiat, keterjangkauan, yang
dan jangka waktu penarikan singkat (Harper 2003). Meskipun
banyak penelitian telah menilai efek anestesi pada hias
ikan diangkut dalam kantong plastik (Teo et al 1989;.
Pramod et al 2010.) dan transportasi low-density dibudidayakan
fi remaja sh, efek (Guo et al, 1995). anestesi pada
kelangsungan hidup remaja dan kualitas air selama high-density transportasi
dalam kantong polietilen yang tidak diteliti dengan baik.
Redtail pisau (atau pisau Mongolia) menjadi mongolicus penyembah adalah
penting yg makan ikan ikan di Cina, luas di danau,
sungai, waduk, dan badan-badan air tawar lainnya (CAS 1976). The
spesies ditandai dengan harga tinggi dan potensi pasar yang tinggi
(Zhang 2008). Namun, populasinya telah menurun secara serius
selama beberapa dekade terakhir, terutama karena lebih fi shing, perusakan habitat,
dan polusi air (Zhang 2005; Ye 2007). Untuk membangun kembali
populasi, Kementerian Cina Pertanian memulai saham
program peningkatan di beberapa danau dari cekungan Sungai Yangtze.
Selanjutnya, kolam dan kandang pertanian culters Redtail telah berkembang
pesat, meningkatkan kebutuhan akan transportasi Juvenile.
Namun, kematian yang tinggi telah diamati selama transportasi
untuk culters Redtail (Xu et al. 2009). Tujuan kami dalam penelitian ini
adalah untuk mengevaluasi efek dari MS-222 dan minyak cengkeh pada kelangsungan hidup
remaja selama transportasi Redtail pisau di polietilena
tas. Selain itu, kami memantau parameter kualitas air untuk
membantu menentukan mekanisme penting dari tindakan anestesi.
METODE
Eksperimental Fi Sh.-Kami memperoleh culters Juvenile Redtail
dari Niushan Danau Ikan Breeding Center, Wuhan, Hubei
Province, China. Remaja yang ditebar di kolam budidaya
selama 1 bulan sebelum percobaan. Mereka diberi makan komersial
pellet diet di kolam, tapi makan dihentikan 1 d sebelum
percobaan. Remaja adalah 41 d tua ketika percobaan
mulai (rata-rata ± SE: Total Panjang = 46,09 ± 0,91 mm, Tubuh
. Berat = 0,75 ± 0,04 g)
Anesthetics.-dua anestesi komersial, MS-222 (Sigma
Kimia, St Louis, Missouri ) dan kimia minyak cengkeh murni
(Shanghai Feixiang Pabrik Kimia, Shanghai, China), yang
digunakan untuk membius ringan dengan ikan. Setiap anestesi diuji pada
tiga konsentrasi berdasarkan pengalaman sebelumnya, MS-222 di
10, 20, dan 40 mg / 50 air dan minyak cengkeh pada 2, 5, dan 10 mg / 50.
Natrium bikarbonat digunakan dalam MS-222 Solusi untuk mengatur pH
menjadi 7,0.
Experimental setup.-Percobaan dilakukan pada tanggal 31
Juli 2010. Remaja Scoop-terjaring setelah menjahit dari
kolam yang Batch tertimbang dan dipindahkan ke tas. Delapan puluh empat
tas yang digunakan dalam penelitian ini (7 Waktu Contoh perawatan × 4
× 3 ulangan). Kantong plastik bening yang 20 (lebar 40 cm, 50
tinggi 63 cm) dan disegel untuk kedap udara setelah menambahkan 5 50 dari
air, 15 50 oksigen, yang ikan, dan dosis pengobatan anestesi mereka.
Transportasi kepadatan adalah 50 g ikan / Bag (rata-rata, 67 ikan / bag) atau
1 sampai 50 dari air 10 g ikan (13 ikan / 50 air). Kepadatan ini
didasarkan pada praktek-praktek transportasi yang sebenarnya dan percobaan sebelumnya
untuk mengukur konsumsi oksigen dari remaja.
semua tas yang dimasukkan ke dalam kendaraan dan diangkut sekitar
1 jam ke laboratorium Institut Hidrobiologi,
Cina Academy of Sciences. Cahaya alami dipertahankan
di laboratorium, dan pendingin udara yang digunakan untuk menjaga
suhu udara di 25
◦
C. Percobaan berlangsung selama 24 jam,
dan tiga kantong dari masing-masing perlakuan diperiksa pada setiap 6-h
interval untuk menilai kualitas air.
Air Transport berasal dari Pond budidaya: Suhu
= 29
◦
100, oksigen terlarut (DO) = 6 mg / 50 , pH = 7,8,
konduktivitas = 325 mikrodetik / cm, amonia = 0,47 mg / 50). Selama
percobaan, DO (YSI Model 85 instrumen, YSI Inc, Beijing,
Cina) dan pH (yang YSI pH100) diukur segera setelah
tas dibuka, dan jumlah amonia dititrasi dalam
6 jam setelah tas dibuka. Kadar amonia Jumlah ini
ditentukan dengan metode spektrofotometri reagen Nessler
(Huang et al. 1999). Konsentrasi amonia un-terionisasi yang
dihitung dengan mengalikan jumlah amonia oleh sesuai
faktor konversi sesuai dengan suhu air yang diukur