Cyprinus carpio TESTIS ENDUCING SEX REVERSAL OF NILE TILAPIA Oreochromis niloticus Rahul Ranjan Narayan P Pandit Nabin B Khanal Madhav K Shrestha and James S Diana ID: 816008
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EFFICACY OF COMMON CARP Cyprinus carpio TESTIS ENDUCING SEX REVERSAL OF NILE TILAPIA Oreochromis niloticus
Rahul
Ranjan
,
Narayan
P. Pandit
*
,
Nabin
B.
Khanal
,
Madhav
K.
Shrestha
, and James S. Diana
Department of Aquaculture and Fisheries
Agriculture and Forestry University, Nepal
Slide2IntroductionSex reversal of Nile tilapia (Oreochromis niloticus) using 17α-methyl testosterone (MT) is the most commonly used method.
There is concern about the residual effect of MT on human health and environment.
It is not easily available and more costly in developing countries.
There is a need of exploring alternative
natural androgen sources
. Use of animal testis as a source of natural androgen might be an alternative.
2
Slide3Testis is a good source of androgen.- Bull testis (Phelps et al., 1996), hog testis (Mayer et al., 2008), and ram testis (Haylor and Pascual, 1991)Fish testis is more suitable for sex reversal in tilapiaCommon carp (Cyprinus
carpio)
Early maturationHigher
gonadosomatic
index
Two seasons of maturityEasily availableLess costly than synthetic hormone
3
Common carp testis (CCT)
Slide4ObjectivesTo assess the effectiveness of common carp testis (CCT) feeding on sex reversal of Nile tilapia.
To assess the optimum feeding dose
of CCT
for maximum sex reversal in Nile tilapia
.
To find optimum feeding duration of CCT for maximum rate of sex reversal in Nile tilapia.
4
Slide5Materials and Methods 8-dah (days after hatching) mixed-sex Nile tilapia (GIFT strain) were used5
Slide6Experimental setup and designSix levels of CCT diets were prepared. 0 % CCT with fish meal50 % CCT with fish meal65 % CCT with fish meal
80 % CCT with fish meal
95 % CCT with fish meal
1
00
% CCT with fish mealFed
for three different
durations
(25, 30 and 35 days)
Experimental design- RCBD
Treatment duration- block
Feed types- factors
6
Slide760 fry in each aquarium (1.5 ft x 1.0 ft x 1.5 ft)90% water replaced in each 2 daysFeeding (Twice a day; 10-11 am and 3-4 pm)20% initial weekReduced 2.5% each week till 5%
Quantity fixed on basis of sampled fish
After treatment, fish were transferred to nylon hapa
and reared until 160
dah
with normal feed.7
Slide8Feed preparation8Fresh CCT for drying
Slide99Dried CCTCCT Powder
Slide10Post treatment phaseAfter treatment, fry were transferred to nylon happa (50 cm x 50 cm x 100 cm) and reared until 160 dahFeeding- 5% of body weight with 28% CP
feed
Fortnightly sampling
50% water changed
weekly
10
Feeding in
hapa
Slide11Sex differentiationGonad observationAll fish taken outDissectedGonad observedDetermined with naked eyesConfirmed using staining materialAcetocaramine
(0.5 g caramine
in 100 mL of 45% acetone)
11
Slide12Results and DiscussionSex reversalSex reversal towards male was based on dose dependent manner
12
Figure:
Average male population with different doses of CCT
Slide1313Feed type (CCT%)Treatment duration (days)
Mean
25
30
35
0 (Control)
50.0±0.0
54.2±4.2
54.2±4.2
52.8±1.4
c
50
62.5±7.2
62.5±7.2
75.4±4.0
66.8±4.3
b
65
68.8±3.6
75.0±7.2
72.6±8.3
72.1±1.8
b
80
62.5±7.2
69.6±10.9
79.2±4.2
70.4±4.8
b
95
83.3±4.2
91.7±4.2
90.5±4.8
88.5±2.6
a
100
87.5±0.0
95.8±4.2
95.8±4.2
93.1±2.8
a
Mean (Excluding Control)
72.9±5.3
a
78.9±6.4
a
82.7±4.5
a
Table:
Effect of CCT dosage and treatment duration on proportion of male of Nile tilapia (
Mean±SE
).
Mean values with different superscript letters within column and within row are significantly different (p<0.05)
Slide1414Female gonad under 100x
Male gonad under 100x
Female
Male
Gonadal
structure
Slide1515TestisOvary
Slide16Growth during treatment phase16Figure: Growth trend of fish during sex reversal phase (35 days)
Slide1717Treatment (CCT %)Survival (%)
DWG (mg/fish/day)
SGR (%/day)
0 (Control)
90.00±4.41
a
6.33±0.31
c
8.55±0.14
c
50
60.00±14.81
b
11.93±0.78
ab
10.29±0.19
ab
65
57.78±10.18
b
10.50±0.60
b
9.94±0.16
b
80
62.78±13.47
b
10.98±1.55
b
10.01±0.43
b
95
65.00±13.64
b
14.43±0.43
a
10.83±0.08
a
100
61.67±7.64
b
11.57±1.14
ab
10.19±0.27
ab
Table 7:
Growth parameters of fry during treatment phase after 35 days
Mean values with different superscript letters within column and within row are significantly different (p<0.05)
Slide18Growth difference may be due to higher crude protein in CCT compared to fish meal.Higher dietary proteinIncreased amount of hormone in dietLower density18
Slide19Water quality during treatment phase19Figure 13: Min- Max temperature and DO in aquarium during sex reversal phase
Slide2020Figure 14: pH in aquarium during sex reversal phase
Slide21Conclusion100% CCT fed for 30-35 days produce significantly higher (95.83±7.22%) male population.Male population increased with increased CCT dose
Increased male population with increased treatment
duration
21
Slide22Recommendations for further studyStudy on androgens present in CCT.Development of processing method.Histological, Immunohistological and steroid hormone profile of sex changed fish.
Develop a methodology for extracting hormone from testis.
22
Slide23Funding for this research was provided by the
The AquaFish Innovation Lab is supported in part by United States Agency for International Development (USAID)
Cooperative Agreement No. EPP-A-00-06-00012-00 and by contributions from participating institutions.
This presentation is made possible by the generous support of the American people through the United States Agency for International Development (USAID). The contents are the responsibility of the authors and do not necessarily reflect the views of USAID or the United States Government. Mention of trade names or commercial products in this presentation does not constitute endorsement or recommendation for use on the part of USAID or AquaFish. The accuracy, reliability, and originality of the work presented are the responsibility of the individual authors.
Slide2424Thank You