Sex‐Reversal of <i>Oreochromis aureus</i> by Immersion in Mibolerone, a Synthetic Steroid<sup>1</sup>

Torrans, Les; Meriwether, Frank; Lowell, Fran; Wyatt, Bill; Gwinup, Paul D.

doi:10.1111/j.1749-7345.1988.tb00935.x

Cited by 11 publications

(4 citation statements)

References 6 publications

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“…In the present study, there was no checking on the sex ratio in seeds due to the administration of the 17β-estradiol so that the sex ratio in seeds was unknown. However, according to Torrans et al (1988), seeds aged 7 days after hatching or total length ranged from 9-13 mm, morphologically have not undergone sex differentiation, so in this study, it is expected that 17β-estradiol does not affect the sex ratio of catfish seeds.…”

Section: Discussionmentioning

confidence: 75%

The use of different 17β-estradiol hormone doses and water temperatures to control cannibalism in catfish Clarias gariepinus seed

Putri

Zairin

Carman

et al. 2020

Jurnal Akuakultur Indonesia

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Cannibalism is a major problem in the intensive catfish hatchery that caused high mortality. This phenomenon is allegedly due to the high level of testosterone hormones in the early larvae and seed stages. Testosterone is a maternal steroid hormone that is transferred directly by the parent to the egg. Catfish broodstock has high testosterone levels during the gonad maturation phase and it enters the eggs during the process of vitellogenesis. A high level of testosterone is considered to cause catfish seeds to behave aggressively and subsequently encourage cannibalism. This testosterone level may be reduced by estrogen through a negative feedback mechanism. This experiment aimed to evaluate the use of several 17β-estradiol doses at different water temperatures to control cannibalism in catfish seeds. This experiment used two factors, i.e. 17β-estradiol doses (0, 20, and 50 mg/kg) coated in the diet and water temperatures (28 and 31°C). The results showed that 17β-estradiol levels in catfish seeds increased with increasing experimental length. The use of 17β-estradiol at low water temperature (28°C) was better in decreasing mortality, while the dose of 50 mg/kg17β-estradiol which applied at 28°C was the best combination in controlling cannibalism on catfish seeds. Keywords: 17β-estradiol, cannibalism, Clarias gariepinus, seed. ABSTRAK Kanibalisme merupakan salah satu masalah utama dalam pembenihan ikan lele intensif karena menyebabkan kematian yang tinggi. Fenomena ini diduga karena kadar hormon testosteron yang tinggi pada tahap larva dan benih. Testosteron merupakan hormon steroid maternal yang ditransfer secara langsung oleh induk ke telur. Induk ikan lele memiliki kadar testosteron yang tinggi pada fase pematangan gonad dan masuk ke dalam telur selama proses vitelogenesis. Tingginya kadar testosteron diduga menyebabkan benih berperilaku agresif dan akan mendorong kanibalisme. Kadar testosteron dapat ditekan dengan meningkatkan kadar hormon estrogen melalui mekanisme feedback negatif. Penelitian ini bertujuan mengevaluasi penggunaan dosis estradiol-17β dan suhu pemeliharaan yang berbeda untuk mengendalikan kanibalisme pada benih ikan lele. Penelitian ini menggunakan dua faktor yaitu dosis estradiol-17β yang berbeda (0, 20, dan 50 mg/kg) yang diberikan melalui pakan, dan suhu pemeliharaan yang berbeda (28 dan 31°C). Hasil penelitian menunjukkan bahwa konsentrasi estradiol-17β pada benih ikan lele meningkat seiring dengan lamanya pemeliharaan. Penggunaan estradiol-17β pada suhu 28°C lebih baik dalam mengurangi mortalitas, sementara dosis estradiol-17β 50 mg/kg pada suhu pemeliharaan 28°C adalah kombinasi terbaik dalam mengendalikan kanibalisme pada benih ikan lele. Kata kunci: benih, Clarias gariepinus, estradiol-17β, kanibalisme.

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Section: Discussionmentioning

confidence: 75%

The use of different 17β-estradiol hormone doses and water temperatures to control cannibalism in catfish Clarias gariepinus seed

Putri

Zairin

Carman

et al. 2020

Jurnal Akuakultur Indonesia

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“…Its active ingredient, 17‐β‐hydroxy‐7α,17‐dimethyl‐estr‐4‐en‐3‐one, is a non‐progestational steroid recommended for oral use to prevent estrus in adult female dogs. Mibolerone has been tested for induction of sex reversal in tilapia 10,11 and immersion of tilapia fry in 0.6 p.p.m. mibolerone for 5 weeks appears to be effective 11 .…”

Section: Introductionmentioning

confidence: 99%

“…Mibolerone has been tested for induction of sex reversal in tilapia 10,11 and immersion of tilapia fry in 0.6 p.p.m. mibolerone for 5 weeks appears to be effective 11 . Oral administration has also been tested but data were limited although the technique has great potential 11 …”

Section: Introductionmentioning

confidence: 99%

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Possible application of mibolerone for induced sex inversion of grouper Epinephelus coioides

2001

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SUMMARY: Thirty immature juvenile grouper Epinephelus coioides (19–168 g bodyweight, BW) were randomly stocked in four units 6 t tanks to determine if mibolerone can be used to induce sex inversion in groupers. After acclimatization and weaning to artificial feed, the feed given daily (4% BW/day) was supplemented with 0, 50, 100, and 200 μg mibolerone/kg feed for about 18 weeks. Thereafter, the hormone treatment was withdrawn and the experiment was terminated at Week 24. Ten fish were killed for gonad histology at stocking to serve as an initial control while about three to five fish were killed every 8 weeks. In general, ovaries of initial controls showed the presence of moderate stromal cells and gonia and few primary oocytes. At Weeks 8 and 16, ovaries of the control fish (0 μg/kg) were similar to that of the initial control except that primary oocytes increased at Week 24. Gonads of fish fed diets containing 100 and 200 μg/kg had none to moderate spermatocytes and few spermatids at Week 8 and 16, although spermatozoa were not observed, indicating that the fish were undergoing spermatogenesis. Spermatogenesis at 50 μg/kg was not as advanced since only few spermatocytes occurred at Weeks 8 followed by moderate gonia and no spermatocytes and spermatids at Week 16. However, the presence of few primary oocytes was observed when mibolerone was withdrawn suggesting that sex‐inversed fish reverted back to a female condition. These results show that sex inversion in juvenile grouper can be induced by oral administration of mibolerone and may have possible application on mature females to produce functional males.

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Molecular cloning, expression and phylogenetic analyses of parvalbumin in tilapia, Oreochromis mossambicus

Lee

Chu

et al. 2006

J. Exp. Zool.

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The gene expression of parvalbumin (Pvalb), a high-affinity calcium-binding protein and the major fish allergen, was significantly increased in the tilapia fry treated with methyltestosterone (MT) as examined using a subtractive hybridization assay. Using the real-time quantitative PCR, we further confirmed the increased Pvalb expression in the MT-treated tilapia fry. The 568 base pairs (bp) tilapia Pvalb (tPvalb) cDNA clone was fully sequenced and found to contain a coding region of 330 bp, which encodes a 108 amino acids protein with a molecular weight of 11,370.5 and an calculated isoelectric point of 4.56. The predicted secondary structure of tPvalb is comprised of seven a helices. It contains two characteristic EF-hand calcium-binding motifs, one PKC and five casein kinase II consensus phosphorylation sites. The tPvalb is highly homologous to the selected fish Pvalbs at a similarity ranging from 53% to 80%. The phylogenetic tree analysis showed that the tPvalb is closest to the Scomber japonicus Pvalb. The tPvalb was found to express in the heart, muscle, gill, kidney, brain and ovary of adult fish by RT-PCR analysis. In situ hybridization also revealed that the tPvalb was highly expressed in the hypothalamus and sarcoplasmic reticulum. A tPvalb glutathione S-transferase (GST) fusion protein was generated and digested by thrombin to remove the GST moiety. Further Western analysis showed that the tPvalb protein was cross-reacted to an anti-rat Pvalb antibody. Those results suggest that Pvalb is evolutionally conserved in tilapia.

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Sex‐Reversal of Oreochromis aureus by Immersion in Mibolerone, a Synthetic Steroid¹

Cited by 11 publications

References 6 publications

The use of different 17β-estradiol hormone doses and water temperatures to control cannibalism in catfish Clarias gariepinus seed

The use of different 17β-estradiol hormone doses and water temperatures to control cannibalism in catfish Clarias gariepinus seed

Possible application of mibolerone for induced sex inversion of grouper Epinephelus coioides

Molecular cloning, expression and phylogenetic analyses of parvalbumin in tilapia, Oreochromis mossambicus

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Sex‐Reversal of Oreochromis aureus by Immersion in Mibolerone, a Synthetic Steroid1

Cited by 11 publications

References 6 publications

The use of different 17β-estradiol hormone doses and water temperatures to control cannibalism in catfish Clarias gariepinus seed

The use of different 17β-estradiol hormone doses and water temperatures to control cannibalism in catfish Clarias gariepinus seed

Possible application of mibolerone for induced sex inversion of grouper Epinephelus coioides

Molecular cloning, expression and phylogenetic analyses of parvalbumin in tilapia, Oreochromis mossambicus

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Sex‐Reversal of Oreochromis aureus by Immersion in Mibolerone, a Synthetic Steroid¹