Jurnal AKUAKULTURA Available online at: Volume 6, Nomor 1, 2022 http://jurnal.utu.ac.id/ P-ISSN: 2579-4752, E-ISSN: 2620-7397 PERFORMA PERTUMBUHAN ROTIFERA (Brachionus rotundiformis) MELALUI PEMBERIAN FERMENTASI IKAN TONGKOL DAN RAGI ROTI GROWTH PERFORMANCE OF ROTIFERS (Brachionus rotundiformis) THROUGH FERMENTED TUNA AND BAKER'S YEAST Ridayus Anima 1) , Afrizal Hendri 1*) , Fazril Saputra 1) , Sufal Diansyah 1) , Radhi Fadhillah 1) 1 Jurusan Akuakultur, Fakultas Perikanan dan Ilmu Kelautan, Universitas Teuku Umar, Aceh Barat * Korespondensi: afrizalhendri@utu.ac.id ABSTRACT Natural feed is one of the inputs that is needed during the rearing phase of fish larvae, especially when the york content has been completely absorbed by the fish's body. There are many types of natural food commonly used by marine fish hatcheries, both phytoplankton and zooplankton. Rotifera (Brachionus rotundiformis) is one of the zooplankton that can be used as natural food for fish larvae. This study aims to determine the effect of fermented tuna and rag roti on the growth performance of rotifers. This research was conducted in November - December 2021 at the Fish Seed Center (BBIP) Busung Indah, Simeulue Regency. The study was conducted experimentally using a completely randomized design (RAL) with four treatment levels and three repetitions. The results showed that different fermented tuna and baker's yeast on culture media had a significant effect on population density and growth rate of Rotifera significantly (P<0.05). Treatment (P4) 8 g of fermented fish added yeast 0.60 g was significantly different from the control treatment (P0), treatment (P1), treatment (P2), but not significantly different from the treatment (P3) tuna 8 g added bread yeast 0.45 g. The results of this study showed that the administration of fermented tuna and baker's yeast at a dose of 8 g and baker's yeast 0.60 g had a positive impact on the growth performance of rotifers, with an average of 196 ind/mL/day. Keywords: mackerel fermentation, bread yeast, rotifera. ABSTRAK Pakan alami merupakan salah satu input yang sangat diperlukan ketika fase pemeliharaan larva ikan, khususnya ketika kandungan york telah habis diabsorbsi oleh tubuh ikan. Cukup banyak jenis pakan alami yang lazim digunakan oleh uni pembenihan ikan laut baik phytoplankton maupun zooplankton. Rotifera (Brachionus rotundiformis) merupakan salah satu zooplankton yang dapat dimanfaatkan untuk pakan alami larva ikan. Riset ini bertujuan untuk mengevaluasi performa pertumbuhan rotifera melalui pemberian nutrisi berupa fermentasi ikan tongkol + ragi roti. Penelitian telah dilaksanakan pada bulan November sampai Desember 2021 di Balai Benih Ikan Pantai (BBIP) Busung Indah Kabupaten Simeulue. Riset ini bersifat eksperimental menggunakan Rancangan Acak Lengkap (RAL) dengan empat taraf perlakuan dan tiga kali pengulangan. Hasil penelitian menunjukkan bahwa pemberian nutrisi berupa fermentasi ikan tongkol + ragi roti pada media kultur berpengaruh nyata terhadap kepadatan populasi dan laju pertumbuhan rotifera (P<0,05). Pemberian nutrisi berupa fermentasi ikan tongkol pada dosis 8 g + ragi roti 0.60 g berdampak positif terhadap performa pertumbuhan rotifera yaitu rata-rata 196 ind/mL/hari. Kata kunci: fermentasi ikan tongkol, ragi roti, rotifera 1 Jurusan Akuakultur, Fakultas Perikanan dan Kelautan, Universitas Teuku Umar Jalan Kampus Alue Peunyareng, Kec. Meureubo, Kab. Aceh Barat, email: khairulsamuki@gmail.com