Effect of fluoxymesterone on sex ratio and growth of Nile tilapia, Oreochromis niloticus (L.)

Phelps, Ronald P.; Cole, William Morse; Katz, Tal

doi:10.1111/j.1365-2109.1992.tb00784.x

Cited by 13 publications

(11 citation statements)

References 8 publications

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“…In this study, we observed a relatively high male percentage (90:18%) compared to the females in those groups fed with androgenised feed compared to those not subjected to the hormone. These results in terms of male to female percentage are similar to other findings [17][18][19] implying that 17-α methyl testosterone hormone is an effective androgen in sex reversal even in open environments. However, our findings male; female sex ratios (90 ± 1.10: 18 ± 1.54 %) were rather low compared to the other researchers [17,20].…”

Section: Discussionsupporting

confidence: 90%

“…These results in terms of male to female percentage are similar to other findings [17][18][19] implying that 17-α methyl testosterone hormone is an effective androgen in sex reversal even in open environments. However, our findings male; female sex ratios (90 ± 1.10: 18 ± 1.54 %) were rather low compared to the other researchers [17,20]. Even though the feeding rate was similar, fed at 20% body weight four times a day, a low male percentage observed in our study seem to be highly correlated to the low temperature (19-24°C) compared to 26°C used by Phelps et al [17].…”

Section: Discussionsupporting

confidence: 90%

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Aspects of a Monosex Population of Oreochromis Niloticus Fingerlings Produced Using 17-α Methyl Testosterone Hormone

Utete¹,

Muposhi²

2012

J Aquac Res Development

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The study investigated the efficacy of 17-α methyl testosterone hormone in producing a mono male sex population in Oreochromis niloticus fry under tropical conditions in ponds in Zimbabwe. Fry were randomly stocked in ten fry tanks at 15000 fry per tank. Five randomly selected tanks received androgenised feed with 17-α methyl testosterone (M T hormone). The other five tanks received feed which had not been treated with 17-α methyl testosterone. The sex ratios, feed conversion ratio, growth rate and survival were established after three months. Fry fed to a diet treated with MT had a significantly higher growth rate as compared to those fed to a non hormone treated diet. Individuals whose diet was androgenised had a higher survival rate as compared to those individuals whose diet was not treated. We concluded that MT has a high efficacy in producing a male population in O. niloticus under tropical conditions and that treatment duration during cold periods be increased to 30 days as compared to the usual 21 days currently being used at Lake Harvest Aquaculture Zimbabwe so as to produce a male population above 95% for optimality.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 90%

Aspects of a Monosex Population of Oreochromis Niloticus Fingerlings Produced Using 17-α Methyl Testosterone Hormone

Utete¹,

Muposhi²

2012

J Aquac Res Development

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“…However, the percentage of males obtained from the 40 (93.4%) and 60 mgMT/kg (94.4%) fish was insignificant (P>0.05).The proportion of males is consistent to what was reported by Phelps et al [33] (97.8% males), and [7] (96.8% males) on O. niloticus who set their experiment in hapas for 28 days at 60 mgMT/kg feed the protocol similar to the current study. Shepperd [34] and Celik et al [11] found similar results on Red tilapia in steel tank and aquaria on O. niloticus respectively.…”

Section: Discussionsupporting

confidence: 81%

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

As¹,

Kang'ombe²,

Kassam³

et al. 2012

J Aquacult Res Dev

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Three different doses (40, 60 and 90 mgMT/kg feed) of 17α-methyl testosterone (MT) were administered to Oreochromis andersonii. Growth, reproduction and sex ratios were evaluated. The fish raised on 60 mgMT/kg feed had the highest final mean weight and this was significantly different (P<0.05) from other hormone doses. Additionally, the 60 mgMT/kg fed fish had the lowest fecundity and reproductive effort. Histological examination of the gonads did not show any differences between the control and MT fed fish. The gross margin ratio (GMR) of the control group was the highest (P<0.05). The proportion of males in MT treated groups deviated significantly from the control group although the percentage of males obtained from the 40 mgMT/kg feed (93.4%) and 60 mgMT/kg feed (94.4%) fish was insignificant (P>0.05). Furthermore, the highest dose used produced a significantly lower (P<0.05) male proportion (79.3%) than the other treatments. The anabolic effect of androgen MT diminished over time.Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) The fish were provided with the prepared feed twice a day (10:00 and 15:00 hrs) daily except Sundays calculated at 5% live body weight of the fish. Fortnightly, a total of 160 fish (20 from each tank or 40 from each treatment) were weighed and lengths (standard length (SL) and total length (TL)) measured according to the procedures described by Skelton [13] after the fish were anaesthetized in 5g/l crude clove (Unilever South Africa Foods (Ptv) Ltd) to reduce stress. The experiment lasted for 119 days.At the end of the experiment all the fish were caught and their weights and lengths (SL and TL) determined. In addition, 20 fish (10 of each sex) were taken to the laboratory for gonad and liver extraction and weighing for maturity stage [14] (Table 2) and hepatosomatic index (HSI) calculation. The fish were sexed by checking the genital papillae with the help of the magnifying glass (Figure 2). The gonads were then fixed in 10% formalin in individual vials for later egg counting and diameter determination on an ocular scale mounted to the microscope (Nikon NFX-35) (500x power) after blotting them on paper.Further 20 gonads (10 of each sex) from every treatment were prepared for the histological examination by fixing them 10% formalin solution. They were then embedded in paraffin wax after dehydration in series of methanol (70, 80, 90, 100%) and sectioned in 3 µm and then stained with Haematoxylin and Eosin before they were mounted on slides with DPX mountant. The slides were then examined on the Olympus microscope (150X power) and a picture taken with Kodak camera. Sex ratio determinationOreochromis andersonii breeders were stocked in 250 m 2 semiconcrete pond at the sex ratio of 3:1 (female=71.191 ± 12.093 g: male=174.857 ± 19.828 g; mean ± SD). After twenty one (21) days, the eggs were recovered from the mouth of the four brooding female fish and were immediately taken to the indoor hatchery for incubation in the jars at 28°C with the help ...

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“…Similar results were also observed for protein efficiency ratio. Matty and Lone (1979) and Matty (1980 &1981) demonstrated that natural androgens and MT treatment enhanced the feed efficiency values in common carp, Cyprinus carpio L. Also, Phelps et al, (1992) obtained similar results when O. niloticus fry was fed the diet treated with MT at 60 mg/kg of feed for 28 days.…”

Section: Feed Conversion Ratio (Fcr)mentioning

confidence: 85%

Growth and feed utilization of the Nile tilapia fry pre-exposured to different water temperatures and hormone 17α methyltestosterone

Agouz¹

2016

Egypt. J. of Aquatic Biolo. and Fish.

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The effect of water temperatures in combination with or without hormone 17α methyltestosterone application for different periods (1, 2, 3 and 4 weeks) on sex ratio and survival rate of O. niloticus fry were investigated. Three rearing temperatures (25, 30 or 30°C) were tested; within each rearing treatment two levels of 17α methyltestosterone (0 or 60 mg/kg basal diet) were used. Sex ratio and survival rate of O. niloticus fry were determined after 1, 2, 3 and 4 weeks. Therefore, 24 groups (3 × 2 × 4) were tested. At the end of this experiment, sex reversed fry were chosen at random from each group and stocked in 72 L aquaria (3 replicates for each group, 3×24) and used to investigate the effect of rearing water temperature in combination with or without hormone application for different periods (1, 2, 3 and 4 weeks) on growth performance and feed utilization of O. niloticus fry during one month after treatment period.The highest final body weight (BW), body length (BL), weight gain (WG), specific growth rate (SGR) and the worst feed conversion ratio (FCR) were obtained for fry reared (pre-exposured) at 35°C and fed on the diet supplemented by 60 mg 17α-MT for one week and the lowest final BW, BL, WG, SGR and the best FCR were recorded for the control fry group (reared at 25°C and fed on the diet free from 17α-MT for two weeks) and the same trend was also observed for tilapia fry pre-exposured to each of water temperature and 17α-MT for three or four weeks. For the control, fry group rearing periods (1, 2, 3 or 4 weeks) did not affect the final BW, BL, WG, SGR or FCR of growing the Nile tilapia fry while, increasing the rearing period for C35H1 gradually increased these parameters.

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Effect of fluoxymesterone on sex ratio and growth of Nile tilapia, Oreochromis niloticus (L.)

Cited by 13 publications

References 8 publications

Aspects of a Monosex Population of Oreochromis Niloticus Fingerlings Produced Using 17-α Methyl Testosterone Hormone

Aspects of a Monosex Population of Oreochromis Niloticus Fingerlings Produced Using 17-α Methyl Testosterone Hormone

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

Growth and feed utilization of the Nile tilapia fry pre-exposured to different water temperatures and hormone 17α methyltestosterone

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