Dinar Tri Soelistyowati

Aromatase gene expression and masculinization of Nile tilapia immersed in water 36 °C containing 17α-methyltestosterone

ABSTRACT Immersion of undifferentiated larval tilapia in high temperature and 17α-methyltestosterone (MT) cab increase the male ratio. However, the effectiveness of immersion in high temperature of water containing MT remains to be evaluated. The purposes of this study were: 1) evaluate the male ratio, growth, and survival of tilapia, and 2) analyze the aromatase brain-type gene expression level in tilapia after immersing in high temperature (36 °C) containing MT at 2 mg/L for four hour with single and double immersion. Aromatase gene expression was analyzed by semi-quantitative RT-PCR (sqRT-PCR) method. The result showed that higher monosex male ratio was obtained by single immersion of MT at 36 °C at room temperature. Gene expression level of aromatase brain-type was lower on single immersion and increased significantly at second immersion compared to control (immersion at room temperature without MT). Immersion using MT and high temperature had no significant effect on fish survival. However the specific growth rate and fish biomass were higher than control. Thus, monosex male tilapia can be produced by single immersion of undifferentiated larvae at 36 °C temperature containing MT. Keywords: male ratio, aromatase, Oreochromis niloticus , temperature, 17α-methyltestosterone ABSTRAK Perendaman larva ikan nila yang belum terdeferensiasi kelaminnya dengan suhu tinggi dan hormon 17α-metiltestosteron (MT) dapat meningkatkan nisbah kelamin jantan. Tetapi, efektivitas perendaman menggunakan MT pada suhu tinggi belum diteliti. Tujuan dari penelitian ini adalah 1) mengevaluasi nisbah kelamin jantan, pertumbuhan, dan kelangsungan hidup ikan nila, dan 2) menganalisis ekspresi gen aromatase tipe-otak pada ikan direndam menggunakan MT dengan dosis 2 mg/L selama empat jam sebanyak satu dan dua kali perendaman pada suhu 36 °C. Ekspresi gen aromatase dianalisis menggunakan metode RT-PCR semi-kuantitatif (sqRT-PCR). Hasil penelitian menunjukkan bahwa kombinasi perendaman MT satu kali pada suhu 36 °C lebih tinggi menghasilkan ikan nila jantan monoseks dibandingkan perendaman MT satu kali pada suhu ruang. Tingkat ekspresi gen aromatase tipe otak pada perendaman satu kali lebih rendah, dan meningkat secara signifikan pada perendaman kedua dibandingkan dengan kontrol (perendaman pada suhu ruang tanpa MT). Perendaman larva menggunakan MT dan suhu 36 °C tidak berpengaruh nyata terhadap kelangsungan hidup, tetapi laju pertumbuhan spesifik dan biomassa ikan perlakuan tersebut lebih tinggi daripada kontrol. Dengan demikian, ikan nila jantan monoseks dapat diproduksi dengan perendaman satu kali pada larva yang belum terdeferensiasi jenis kelaminnya menggunakan MT pada suhu 36 °C. Kata kunci: rasio jantan, aromatase, Oreochromis niloticus , suhu, 17α-metiltestosteron

Genetic variability and performance of Asian swamp eel Monopterus albus (Zuiew, 1793) from West Java cultured in saline water medium

ABSTRACT Asian swamp eel Monopterus albus (Zuiew, 1793) is freshwater fish species which is prospective for domestic and export markets. The production is limited depend on the catches of natural population. The cultivation of eel has been carried out to increase the production for sustainability. This study was conducted to evaluate the genetic variability and performance of Asian swamp eel from West Java and its potential cultivation in water based media with salinity. Three populations from West Java were collected of different altitudes from Sukabumi (673 m asl), Cianjur (429 m asl), Karawang (51 m asl) sized 19–26.5 cm and weighed 4.95–11.4 g. The cultivation was performed during 30 days in water media without substrate at salinity 6 ppt with density of 1 kg/m2 and maintenance at container 50×30×30 cm completed with shelter pipe of ¾ inches diameter and 20 cm length, height of water 10 cm and water exchange 100% every day, fed at satiation using Tubificidae once a day. Genetically, all of the populations showed low heterozygosity at 1.19–1.23% and genetic distance 0.01–0.04. Asian swamp eel adapted better at water salinity 6 ppt which indicated by low mesure of osmotic gradient and blood glucose. Asian swamp eel from Karawang showed superior at survival rate (90%) and daily growth rate (1.42/day). Keywords: Asian swamp eel, Monopterus albus , cultivation, genetic variability, salinity ABSTRAK Belut sawah Monopterus albus (Zuiew, 1793) merupakan komoditas ikan air tawar potensial di pasar domestik maupun ekspor, namun produksinya masih mengandalkan hasil tangkapan dari alam karena budidaya belum berkembang. Penelitian ini bertujuan untuk mengevaluasi keragaman genetik dan keragaan belut sawah asal Jawa Barat dan potensinya untuk dikembangkan dengan teknik budidaya di air bersalinitas tanpa lumpur. Tiga populasi belut sawah dikoleksi dari lokasi di Jawa Barat dengan ketinggian berbeda yaitu Sukabumi (673 m dpl), Cianjur (429 m dpl), Karawang (51 m dpl). Sumber genetik belut berukuran 19–26,5 cm dan bobot berkisar 4,95–11,4 g dipelihara selama 30 hari dalam media air tanpa substrat bersalinitas 6 ppt. Wadah pemeliharaan berukuran 50×30×30 cm dilengkapi shelter pipa paralon diameter ¾ inci dan panjang 20 cm serta ketinggian air 10 cm. Padat penebaran ikan 1 kg/m2 (20 ekor/wadah), serta pergantian air 100% dilakukan setiap hari dan pemberian pakan berupa Tubificidae secara at satiation satu kali sehari. Secara genetik ketiga populasi menunjukkan tingkat heterosigositas yang rendah yaitu berkisar 0,19–0,23 % dan jarak genetik 0,01–0,04. Belut sawah menunjukkan respons adaptasi yang baik dalam media air tanpa substrat pada salinitas 6 ppt berdasarkan indikator beban osmotik dan kadar glukosa yang rendah. Belut sawah asal Karawang unggul pada laju pertumbuhan harian (1,42/hari) dan kelangsungan hidup (90 %). Kata kunci: belut sawah Monopterus albus , budidaya, keragaman genetik, salinitas

Masculinization of betta fish Betta splendens by embryo immersion in extract of purwoceng Pimpinella alpina

ABSTRACT This study aimed to examine the effect of extract of purwoceng Pimpinella alpina for masculinization of Betta splendens . This research used completely randomized design with three treatments that were distinguished by doses of purwoceng extract, which were 10, 20, and 30 µL/L, and 0 µL/L as control. The treatments were given by immersion to 35 embryos at eye spots phase or about 28-hours after fertilization, for eight hours. The immersion process was done for 8 hours. The result showed that 20 µL/L dose of purwoceng extract produced 62.66% male, and hatching rate was 85.71%. This male percentage was higher compared to control (45.91%), but the hatching rate was lower than that of control (98.57%). At the higher dose (30 µL/L), male fish population and hatching rate reduced respectively 39.72% and 68.57%, respectively. Keywords: masculinization, embryo immersion, purwoceng extract, Betta splendens ABSTRAK Penelitian ini bertujuan untuk mengevaluasi pengaruh dosis ekstrak purwoceng Pimpinella alpina extract dalam maskulinisasi ikan cupang hias Betta splendens . Penelitian ini menggunakan metode rancangan acak lengkap dengan tiga perlakuan dan tiga ulangan dosis ekstrak purwoceng. yaitu 10, 20, dan 30 µL/L, serta perlakuan 0 µL/L sebagai kontrol. Perlakuan diberikan melalui perendaman selama delapan jam terhadap 35 embrio saat memasuki fase bintik mata atau sekitar jam ke-28 setelah pembuahan. Hasil penelitian menunjukkan bahwa dosis ekstrak purwoceng 20 µL/L menghasilkan persentase ikan jantan sebesar 62,66%, dan daya tetas telur sebesar 85,71%. Persentase jantan tersebut lebih tinggi daripada kontrol (45,1%), tetapi derajat penetasannya lebih rendah daripada kontrol (98,57%). Pada dosis yang lebih tinggi (30 µL/L), populasi ikan jantan (39,72%), dan derajat penetasan (68,57%) adalah menurun. Kata kunci: maskulinisasi, perendaman embrio, ekstrak purwoceng, Betta splendens