Effect of Estradiol-17β Injection on Gonad Development of White Shrimp (Litopenaeus vannamei)

<p>The methods for hormonal control of shrimp reproduction are very limited, and only eyestalk ablation is used to induce ovarian development and spawning in shrimp farming. The occurrence of vertebrate-type steroid hormones in crustaceans have been reported, however, their physiological role...

Full description

Bibliographic Details
Main Authors: . Tarsim, M. Zairin Junior, E. Riani
Format: Article
Language:English
Published: Asosiasi Sains Akuakultur Indonesia 2007-01-01
Series:Jurnal Akuakultur Indonesia
Online Access:http://journal.ipb.ac.id/index.php/jai/article/view/4007
Description
Summary:<p>The methods for hormonal control of shrimp reproduction are very limited, and only eyestalk ablation is used to induce ovarian development and spawning in shrimp farming. The occurrence of vertebrate-type steroid hormones in crustaceans have been reported, however, their physiological role are not sufficiently understood. The present study analyzed the effect of estradiol-17&beta; injection on gonad development of white shrimp, <em>Litopenaeus vannamei</em>. The estradiol-17&beta; dose 0.10 &mu;g/g body weight were used. The treatments consisted of control, single injection (day 0) and double injection (day 0 and 6). The females broodstock were cultured for 12 days. The result showed that estradiol-17&beta; had positive effect on gonad development. The gonado somatic index (GSI) and oocytes diameter in treatment larger than the control. Double injection had highest effect with ∆GSI and oocytes diameter was 0.453<sup> </sup>&nbsp;and 23.97 &micro;m, respectively. The only oocytes previtelogenesis was found in gonad. It indicated that estradiol-17&beta; important to induce endogenous vitellogenesis. Gonad development probably affected by gonad inhibiting hormone in the eyestalk. It was inhibited oocyte maturation. The polypeptide sub unit was observed in vitellin of ovari by SDS-PAGE. The molecular weights of approximately 95, 98, 109 and two units higher than 118 kDa of protein marker.</p> <p>Keywords: Gonad, estradiol-17&beta;, oocyte, <em>Litopenaeus vannamei</em></p> <p>&nbsp;</p> <p>ABSTRAK</p> <p>Teknologi reproduksi dalam pembenihan udang belum mengalami perkembangan yang signifikan.&nbsp; Pada umumnya untuk mempercepat kematangan gonad induk udang digunakan teknik ablasi. Mekanisme dan peranan hormon pada proses reproduksi udang belum banyak diketahui. Keberadaan hormon steroid pada krustase telah dikemukaan oleh beberapa peneliti, tetapi peranannya belum banyak diketahui.&nbsp; Pada penelitian ini dikaji pengaruh penyuntikan hormon estradiol-17&beta; pada perkembangan gonad induk udang putih (<em>Litopenaeus vannamei</em>).&nbsp; Penelitian ini menggunakan dosis 0,10 &mu;g/g bobot tubuh dengan perlakuan penyuntikan tunggal (hari ke-0) dan ganda (hari ke-0 dan ke-6). Sebagai pembanding dilakukan uji tanpa perlakuan (kontrol). Untuk melihat respon perkembangan gonad, pemeliharaan induk dilakukan selama 12 hari. Hasil penelitian menunjukkan bahwa estradiol-17&beta; berpengaruh positif pada perkembangan gonad. <em>Gonado somatic index </em>(GSI) dan rata-rata diameter oosit pada perlakuan relative lebih tinggi dibandingkan kontrol. Penyuntikan ganda memberikan pengaruh paling besar dengan peningkatan GSI sebesar 0,453<sup> </sup>&nbsp;dan rata-rata diameter oosit 23,97 &micro;m. &nbsp;Oosit pada gonad hanya mampu berkembang hingga tahap previtelogenesis.&nbsp; Hal ini menunjukkan bahwa estradiol-17&beta; berperang dalam vitelogenesis endogenous. Keberadaan hormon penghambat perkembangan yang dihasilkan tangkai mata diduga menyebabkan oosit tidak dapat mencapai matang. Analisis SDS-PAGE menunjukkan bahwa protein kuning telur pada gonad terdapat &nbsp;5 sub unit dengan perkiraan bobot 95, 98, 109 kDa dan dua unit &gt;118 kDa.</p> <p>Kata kunci: Gonad, estradiol-17&beta;, oosit, <em>Litopenaeus vannamei</em></p>
ISSN:1412-5269
2354-6700