摘要：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
