Pulau Tarakan merupakan salah satu pulau di Provinsi Kalimantan Utara yang memiliki luas sekitar 250 km2 dan sebagian besar pesisirnya masih ditum buhi oleh hutan mangrove. Pada Pulau Tarakan terdapat usaha budidaya kepiting bakau yang salah satunya adalah budidaya kepiting soka (soft crab). Penelitian ini bertujuan untuk mengetahui pemanfaatan ikan tempakul (Periophthalmodon schlosseri ) sebagai pakan alami pada budidaya kepiting soka di kota Tarakan. Penelitian ini dilakukan dengan menggunakan Rancangan Acak Lengkap (RAL). Percobaan terdiri dari 3 (tiga) perlakuan dengan 5 (lima) ulangan yaitu perlakuan A diberikan pakan alami mujair, perlakuan B diberikan pakan alami berupa ikan tempakul (Periophthalmodon schlosseri, dan perlakuan C diberikan pakan alami berupa udang. Berdasarkan hasil pemeliharaan, diperoleh nilai kelangsungan hidup (SR) yang paling tinggi yaitu terdapat pada perlakuan B pakan ikan tempakul 80%, dan perlakuan A pakan ikan mujair 60%, sementara perlakuan C pakan udang mendapatkan SR yang sangat rendah yaitu 40%. Proses molting yang paling cepat pada perlakuan B pakan ikan tempakul yaitu dengan rata-rata 23 hari, sedangkan pada pelakuan A pakan ikan mujair membutuhkan waktu 26 hari, dan perlakuan C pakan udang membutuhkan waktu molting 27 hari. Berdasarkan hasil penelitian didapatkan hasil pertumbuhan berat mutlak yang terbaik didapatkan pada perlakuan A pakan ikan mujair dengan bobot rata-rata 25% dibandingkan antara perlakuan B pakan ikan tempakul dengan bobot rata-rata yaitu 24% dan perlakuan C pakan udang dengan bobot rata-rata yaitu 16,5%. Hasil anova pada percepatan moulting menunjukkan bahwa semua perlakuan tidak berbeda nyata (P > 0,05); berat mutlak pada semua perlakuan tidak berbeda nyata (P > 0,05) ; kelangsungan hidup pada semua perlakuan berbeda sangat nyata (P < 0,05).
Kata Kunci: Kepiting bakau, Pakan Alami, Molting

Tarakan is one island in North Kalimantan Province with an area of approximately 250 km2 in which mangrove forest has grawn in its most costal area. In Tarakan Island, there were many mud crab cultivations, inckuding soft-shell crab. The purpose of aims to the utilization of giant mudskripper (Periophthalmodon schlosser) as natural feed for the cultivated soft-shell crabs in Tarakan. This research used a completely randomized design. The experiments were made in three tratments with five repetition. Treatment A was given as natural feed. Based on the cultivation results, the highest survival value was in level could reach up to 80%. In treatment A, which was given Mujair fish as natural feed, the soft-shell crab survival level could reach up to 60%. Treatmen C which was given shrimp as natural feed had the lowest soft-shell crab survival level of only 40%. The fastest molting process was in treatment B which was given giant mudskripper as natural feed with an average of 23 days. Treatmen A which was given Mujair as natural feed required an average molting time of 26 days. Treatment C which was given shrimp as natural feed required a molting time up to 27 days. Based on the research results, it was obtained that the best absolute weight growth was in Treatment A with the average weight of 25% when compared to Treatment B which average weight was at the average of 24%, while in treatment C, the average weight was only 16,5%. The results of Analysis og Variance (ANOVA) on molting speed, show that all treatment had no significant difference (P > 0,05); absolute weight in all treatment also had not significant difference (P > 0,05); yet, survival level in all treatment greatly had a significant difference (P < 0,05). Keywords: Mud crab, natural feed, molting