Presented by -Wahida Haque (st105569)

AARM, SERD

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EFFECTS OF MEDICATIONS ON THE SURVIVAL OF WILD CAUGHT

SNAKEHEAD (Channa striatus) FRY DURING WEANING TO PELLETED FEED

Introduction Important and popular freshwater fish97% world production from Thailand (FAO,1993)

Monoculture depends mainly on wild fry collection Carnivore, feed is either live feed or trash fish in

cultureLive feed is expensive and trash fish cause

biodiversity lossFor culture, acclimation to dry feed is better option

than thoseLow quality trash fish increase disease incidence

(Wee,1982),pelleted feed has ensured quality (Kaewpaitoon, 1992, Aononong,2008,Wee,1982)

But the problem is- low survival of fry during feed transition, usually 7-24%, if stocked immediately in pond after collection from wild then survival is only 13-15% (Boonyarapatlin, 1985)

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Introduction Cannibalism (Qin, 1996) reduce by size grading and satiation

feedingProtein requirement 35-40% (Samantaray et al.,1997) and fed at 5%

of body wt./day for juveniles for optimum growth (Qin, 1996,1997)

Stocking density 75-400/m2 (Wee, 1982, Aonanong, 2008)

Pathogens in snakehead-BacteriaExternal parasites: Protozoa and Fungi, monogeneansInternal parasites: Helminthes- cestodes, nematodes

and Acanthocephalus(Ref: Boonyaratpalin ,1985, Areerat ,1981, Nash ,1988, Chinabut, 1983, Kaewpaitoon,

1992)

Body symptoms indicate intestinal disease and infestations (Chinabut,1990, Areerat,1981,Limsuwan, 1983, Kaewpaitoon, 1992)

Assumption from body symptoms– presence of parasites in wild caught fry cause low survival during weaning period3

Experimental healthy , dead & moribund fishes

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Healthy fish Healthy fish

Swollen belly

Skin lesions

Body emaciation

Belly disruption Deformed body

Introduction Potential pathogen source are trash fish as fishes fed marine

trash fish found to be infected with internal parasites (Chinabut,1990, Limsuwan, 1983, Kaewpaitoon, 1992) and wild source before collection

Effectiveness of the drugs used by some farmers informally to improve survival need to be investigated -formalin for external pathogen, antibiotic for bacteria and rotab for internal parasites

Problem StatementMortality of Snakehead fry during weaning to artificial or

pelleted feed

HypothesisThere is no difference of the survival of Snakehead fry when

treated with drugs during weaning to pelleted feed by using feed combinations

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Introduction Overall objectiveTo develop a suitable weaning method by using

feed combinations along with medication to ensure high survival rate

Specific objectivesTo improve the survival by application of three

medications during weaningTo quantify the effect of medication on survival

rateTo evaluate the effectiveness of three

medications used by some farmers during weaning

To provide some preliminary scientific information about snakehead fry weaning

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Introduction Scopes

Improvement of weaning method and survival rateIdentification and Reduction of the mortality factorsDetermine suitable medication

LimitationsLimited experimental units and supporting literatures Supply of quality and same aged seed, timing and

unavailability of raw materials supply, cost of feed and drug

Water quality, environmental fluctuationMicrobiological infection and identification,

cannibalism ,stress Specific drug for specific pathogenBudget shortage, wastage of time, money and labour,

dependency Language and communication7

Experiment-1Materials and MethodsExperimental fish

Wild caught Snakehead fry about 1-2.5 inch size

Age of about 1 month (Marimuthu, 2007)

Collected from Suphanburi fishers Initial acclimatization for 5 days

Stocking density65 fry/ hapa

Experimental unitsHapa of 1 m2 size, 3 earthen ponds of 200 m2

Water depth about 30-40 cm inside hapaHapa covered with net to avoid predation and

escaping8

Materials and Methods cont’d

Experimental indicatorSurvival rate

Experimental drugs/medicinesFormalin bath- 37%

formaldehyde solution ; dose as 35ppm for 30 min with continuous aeration

Oxytetracycline- 25mg/kg of body weight/day in feed for 10 days

Rotab- 0.1% of Piperazine citrate /kg of feed fed at a rate of 1% of body weight/day, twice in three weeks

Ref: FDA 1992, Boonyaratpalin,1985, Yolande,2005, Noga,20009

Materials and Methods cont’d

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Experimental feedTrash fish and frog feed (40% protein) in

feed combination as 100: 00, 80:20, 60:40, 50:50, 40:60, 20:80 and 00:100

Each feed combination used for 3 daysFeeding protocol

Fed 3 times/day (7 am, 12.00 & 5 pm)until satiation (Wee 1982)

ManagementWeekly water fillingDead fish removalChecking of hapa and covers

Materials and Methods cont’d

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Size GradingBy 0.75 and 1 cm grading net at the beginning

and after10 daysLength and weight

Randomly initial and final length of 20 fry was measured

Water quality measurementTemperature, DO, pH -dailyNH3 and NO2 - weekly

Estimation of survival rateSR%= (No of final harvest x100)/No of initial

stockingData analysis by -Microsoft Excel, SPSS 16.0

One way ANOVA and Tukey’s HSD Post Hoc

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Experimental design-1CRD with 3 replicate of each treatmentDuration 3 weeks

Initial fry stock

Formalin

Antibiotic

Rotab

Formalin + antibiotic

Formalin + Rotab

Rotab + antibiotic

Formalin + antibiotic + Rotab

No drug (control)

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Experimental hapa Setup 1 in three ponds by CRD

FR

RA

FAR

FA

C

A

R

F

FA

FR

C

RA

R

F

FAR

A

A

F

R

FA

RA

C

FR

FAR

Results: Graph showing the survival rate of eight treatments in experiment 1

Survival rate of T1,T2, T3, T4,T5,T6, T7 and (T8) are 43.59±2.35, 61.03±3.88,71.28±6.41, 59.49±3.88,73.84±4.07, 84.62±10.09, 80.00±4.62,42.56±6.41 respectively

The bars with different superscript are significantly different (P<0.05)

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Results: Water Quality parameters in experiment 1

Values with same superscript in a same row are not significantly different (P<0.05)15

Parameters Pond-1 Pond-2 Pond-3Temperature C

28.02 ± 0.64a

27.95 ± 0.63a

27.69 ± 0.81a

DO mg/l 4.65 ± 0.64a

5.51 ± 0.85b

5.57 ± 0.73b

pH 7.76 ± 0.10ab

7.85 ± 0.18a

7.71 ± 0.20b

NH3mg/l 0.04 ± 0.01a

0.12 ± 0.07a

0.06 ± 0.03a

NO2 mg/l 0.02 ± 00ab

0.04 ± 0.01a

0.01 ± 0.00b

Findings of experiment 1Rotab alone is effective, Rotab alone

(71.28 ± 6.41) and a combination of Rotab with Oxytetracycline (84.62 ± 10.09) had relatively higher (P <0.05) survival rate than the control treatment but a high coefficient of variation (9 - 12%) was observed.

Formalin was found non-effective to improve survival rate as formalin treatment had no variation with control indicate no significant presence of external pathogen

The potentiality of endoparasites and bacterial pathogens assumed

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Experiment - 2

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Second experiment was conducted to confirm the previous result whether only Rotab is effective or not

Materials and Methods is same as experiment 1 except-

Stocking density- 58 fry/ hapaExperimental drugs- only Oxytetracycline and

RotabParasites count : Gross examination of the

intestine by wet mount microscopy for the presence of Nematodes, Cestodes and Acanthocephalans (Kabata,1985). Sample size 25 fish/group (randomly selected) assuming parasitic carrier prevalence more than 10% (Kabata, 1985). The parasites were identified as Kabata (1985), Ribelin (1975), Roberts (1978 and 1974).

Experimental design-2CRD with 3 replicate of each treatmentDuration 3 weeks

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Initial fry stock

Antibiotic

Rotab

Rotab + Antibiotic

No drug (control)

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Experimental hapa Setup 2 in three ponds by CRD

RA

C

A

R C

RA

R

A A

R

RA

C

Results: Graph showing the survival rate of four treatments in experiment 2

Survival rate of Rotab (T1), Antibiotic (T2), Rotab+ Antibiotic (T3) and Control -No drug (T4) are 93.11± 2.98,84.48 ±1.73,94.25 ± 2.63 and 72.99 ± 6.06 respectively with stocking density 58 fry/hapa

The bars with different superscript are significantly different (P<0.05)

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Results: Water Quality parameters in experiment 2

No parameter showed significant difference among ponds ; Values with same superscript in a same row are not significantly different (P<0.05)

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Parameters

Pond-1 Pond-2 Pond-3

Temperature C

33.17±1.33a

32.77±1.29a

32.38±1.29a

DO mg/L 5.15±1.60a

5.28±1.34a

4.31±1.53a

pH 7.24±0.47a

7.23±0.35a

7.31±0.26a

NH3mg/L 0.05±0.01a

0.15±0.08a

0.06±0.01a

NO2 mg/L 0.03±0.01a

0.03±0.01a

0.03±0.01a

Parasites found in experimental fishes

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Results: Parasites density in different sample group

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Results

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Nematodes (Camallanus spp. and Spinitectus spp), cestodes (Senga spp) and acanthocephalans (Acanthocephalus spp., Gorgorhynchus spp. and Pallisentis spp.) have been found in our experimental fishes

The average nematode and acanthocephalan number of initial stock (4.52/fish &5.32/fish) didn’t show significant difference with control treatment (4.24/fish and 4.24/fish) but showed significant reduction in Rotab treated (1.84/fish and 2.88/fish) fish sample.

Findings of experiment 2

Higher survival in Rotab + OTC treatment. Rotab alone and OTC+ Rotab combination has significant variation with control

No significant difference (P > 0.05) of survival rate Rotab (93.11 ± 2.98) and combination of Rotab + OTC (94.25 ± 2.63) treatments.

This confirms that Rotab is effective and the use of Rotab as a feed additive is sufficient to maintain relatively high survival during the weaning

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Discussions

In china, OTC used in feed as 50-80 mg/kg body wt./day for 4-6 days as “non-pollution fishery drug” and not different among species (Wang,2004)

OTC depletion occur in fish tissue (Meinertz,2001)

though it may present for 4-6 weeks in tissues after administration (Heijden 1995)

Microbial control has greater influence on the survival and growth of fish larvae during the transitional feeding stage and addition of OTC in feed improves survival (Battaglene, 2006).

OTC in food improved survival during weaning and caused less intesinal disease in striped trumpeter fish (Battaglene, 2006).

OTC is effective and recommended against some major bacterial pathogens of snakehead (FDA,1992, Boonyaratpalin, 1985, Chinabut,1990 etc)26

DiscussionsSome Thai farmers use Rotab (Aonanong, 2008 )

and OTC during weaning to reduce mortality but no scientific literature available

Rotab is Anthelmintic for veterinary and key ingredient is Piperazine which has efficacy to reduce internal helminths and acanthocephalans (Santamarina,1991, Tojo,1998)

Piperazine is effective and recommended against nematodes (Noga,2000, Fairfield,2000,

Youlande,2005) also effective as antiprotozoal in fish (Quintela,2003, Parama,2004), so protozoan also might be treated with Rotab in our study

Non-toxic to aquatic organisms and environment, no potential for bioaccumulation, biomagnification or secondary poisoning (CSTEE, 2004, EU report,2005)27

Discussions

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In general,2nd experiment showed the better survival may be due to better parents and source with better immunity, season

The 1st experiment conducted in cooler months but 2nd experiment in summer. Colder temperatures increase disease susceptibility and reduce growth (Kaewpaitoon,1992, Vivekanandan,1977)

Water quality didn’t show much fluctuation in each experimental period and was within tolerable range (Ng, 1990, Qin, 1997, Courtnenay,2004, Rath,

2000) and it doesn’t cause heavy mortality in snakehead but may affect the growth and production (Wee,1982)

Conclusions Rotab alone or in combination with OTC was found effective

and showed higher survival rateFormalin treatment found ineffective to improve survivalNematode and acanthocephalan density showed reduction

by RotabFishes were infected in wild before collection by the fishersRotab and OTC used as approved dose, no health and

environment riskRotab used by some farmers is effective and the use of

Rotab as a feed additive is sufficient to maintain relatively higher survival during the weaning phase of wild caught snakehead fry to artificial dry feeds.

Finally it can be said that, medications with Rotab and OTC together along with the size grading can improve the survival rate of snakehead fry during weaning to pelleted feed and these drugs, used by some farmers is found to be effective to achieve better survival rate.29

Recommendations

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Genetic study of fryStudy of the source of fryDetermine and Use of pathogen species

specific drugs and dose The quality and shelf life assessment of the

fed trash fishThe microbiological study of the fed trash

fishImpact assessment of the use of these drugs

on other sppEffect of these drugs on the physiology of

the fishes need to be assessed

Few References

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Battaglene, S.C., Morehead, D.T., Cobcroft, J.M., Nichols, P.D., Brown, M.R., Carson, J. (2006).Combined effects of feeding enriched rotifers and antibiotic addition on performance of striped trumpeter (Latris lineata) larvae. Aquaculture 251: 456– 471.

Boonyaratpalin, M., McCoy, E. W., Chittapalapong, T, (1985) Snakehead Culture and its Socio-Economics in Thailand, National Inland Fisheries Institute Kasetsart University and NACA Head Office, Bangkok, Thailand

Kaewpitoon, K. (1992). Utilization of septage-raised tilapia (Oreochromis niloticus) as feed for snakehead (Channa striata). AIT Dissertation. 212pp.

Marimuthu, K and Haniffa, M. A., (2007). Embryonic and larval development of the Striped Snakehead Channa striatus. Taiwania, 52(1):84-92.

Nash, G., R.J. Roberts, S. Chinabut, S. Areerat and C. Limsuwan. 1988. Emaciation of pond-cultured snakehead, Channa striatus (Fowler). J. Fish. Dis., 11: 215-224.

Noga, E.J (2000). Fish Disease : Diagnosis and Treatment. Wiley –Balckwell publishers. Book (367 pages). 2nd edition, page 292.

Qin, J., Fast, A. W. (1996). Size and feed dependent cannibalism with juvenile snakehead Channa striatus. Aquaculture 144: 313-320

Samantaray, K., Mohanty, S.S. (1997) Interactions of dietary levels of protein and energy on fingerling snakehead, Channa striatus. Aquaculture. 156: 241-249 

Wee, K.L (1982). The biology and culture of snakeheads. In: J.F. Muir and R.J. Roberts (edit) Recent advances in aquaculture. Westview press, Boulder Co. pp180-211.

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Thank You