Abstract. The objectives of the present study were to analyze the effect of temperature regimes on stress levels and to determine the suitable water temperature for the domestication of tapah, Wallago leeri Bleeker. A completely randomized method was used in this study, and three levels of water temperature were tested, namely, 27, 29, and 31°C, in seven replicates. A total of 500 experimental fish were collected from the Kampar River, Langgam, Riau, Indonesia, and transported to the Aquaculture Laboratory, Riau University. The fish were reared in 21 tanks at stocking densities of 70-100 fish tank -1 . The fish were fed rough fish three times a day at 08:00, 12:00, and 21:00 for 30 days. Blood samples were taken on days 1, 14, and 29, which were analyzed for cortisol, glucose, and plasma protein. Growth and survival rates were recorded at the end of the experiment. ANOVA showed that water temperature had a significant effect on the stress condition, growth, and survival rate of tapah. Lower blood glucose, protein, and cortisol plasma levels were recorded in fish acclimatized at 29°C with values of 14.44 mg dL -1 , 5.35 g dL -1 , and 6.90 mg mL -1 , respectively.Additionally, higher growth performance (32.30 g) and survival rates (100%) were also found in fish reared at 29°C. It was concluded that the best water temperature for the domestication of tapah is 29°C.

Ikan nila merupakan ikan budidaya yang disukai oleh masyarakat karena dagingnya yang gurih dan lezat. Untuk peningkatkan produksi ikan nila diperlukan pakan yang cukup, baik kualitas maupun kuantitasnya. Pakan merupakan komponen biaya operasional utama pada budidaya ikan nila yang diperkirakan mencapai 40%-60%. Untuk mengatasi hal tersebut diperlukan teknologi yang dapat menekan biaya operasional dalam sistem budidaya. Tujuan dari penelitian ini adalah mengevaluasi frekuensi pemberian pakan yang berbeda terhadap pertumbuhan dan sintasan ikan nila merah (Oreochromis niloticus) yang dipelihara dengan sistem bioflok. Metode yang diterapkan adalah eksperimen dengan empat perlakuan dan tiga kali ulangan. Perlakuannya adalah frekuensi pemberian pakan pelet yaitu (A) 1 kali/hari, (B) 2 kali/hari, 3 kali/hari, dan 4 kali/hari. Ikan nila ukuran 3,71 ± 0,11 cm dan bobot 4,49 ± 0,021 g dipelihara selama 56 hari dalam bak 100 L dengan padat tebar 16 ekor/bak. Ikan dipelihara dengan teknologi bioflok dan diberikan pakan setiap harinya sebanyak 5%/berat biomasa/hari. Hasil penelitian menunjukkan bahwa pemeliharaan ikan nila merah pada sistem bioflok dengan frekuensi pemberian pakan yang berbeda berpengaruh nyata (P<0,05) terhadap performa pertumbuhan, sintasan, dan efisensi pakan. Perlakuan frekuensi pemberiaan pakan 2 kali/hari merupakan perlakuan terbaik menghasilkan pertumbuhan bobot mutlak 23,07 ± 0,89 g; laju pertumbuhan harian 3,23 ± 0,05%; sintasan 91,66 ± 3,60%; dan efisensi pakan 96,73 ± 6,70%.Tilapia (Oreochromis niloticus) is a cultured fish that is favored by the public, because of its delicious meat and high protein content. To increase production, quality, and quantity of feed is needed, feed is the main component in the cultivation system and it is estimated that 40%-60% of the costs incurred in maintaining tilapia are needed. To overcome this, technology is needed that can reduce operational costs in fish culture. The purpose of this study was to evaluate the growth and survival of red tilapia with different feeding frequencies reared with a biofloc system. The research method applied was experimental with four treatments and three replications. The treatment was the frequency of feeding, namely (A) 1 time/day, (B) 2 times/day, 3 times/day, and 4 times/day. Tilapia were reared for 56 days in a 100 L tank with a stocking density of 16 fish/tank. Initial size 3.71 ± 0.11 cm and weight 4.49 ± 0.021. Tilapia are reared with biofloc technology and given daily feed of 5%/weight of biomass/day. The results showed that rearing red tilapia with different feeding frequencies in the biofloc system had a significant effect (P<0.05) on growth performance, survival, and feed efficiency. Treatment B with a frequency of feeding 2 times/day was the best, with absolute growthof 23.07 ± 0.89 g, daily growth rate of 3.23 ± 0.05%, survival rate 91.66 ± 3.60%, and feed efficiency 96.73 ± 6.70%.

Untuk meningkatkan pendapatan nelayan di Kampung Sungai Kayu Ara Kecamatan Sungai Apit Kabupaten Siak perlu diberikan mata pencaharian alternatif berupa budidaya ikan dengan menggunakan teknologi bioflok. Agar teknologi bioflok dapat diaplikasikan, maka masyarakat sasaran perlu diberi pengetahuan dan keterampilan melalui kegiatan penyuluhan. Kegiatan penyuluhan dilakukan untuk meningkatkan ilmu pengetahuan dan keterampilan masyarakat sasaran sehingga mereka dapat mengaplikasikan budidaya ikan dengan teknologi bioflok. Pelaksanaan penyuluhan menggunakan metoda ceramah, diskusi dan demontrasi terhadap berbagai materi yang disajikan. Dari hasil kegiatan diketahui bahwa masyarakat sasaran terlihat antusias terhadap kegiatan yang dilaksanakan, peserta mulai mengerti dan paham terhadap materi yang disajikan dan terjadi peningkatan pengetahuan peserta tentang budidaya ikan lele dengan teknologi bioflok antara 60-80%.

The objectives of this research was 1) to measure the development of mouth opening width and 2) to analyze the digestive enzyme activities. The research was conducted from April to November 2017 in the Hatchery Laboratory, Faculty of Fisheries and Marine Sciences, University of Riau. The results showed that the increase of mouth opening and the rate of gut evacuation of sheatfish larvae was due to the increase of digestive enzyme activities and feed consumption rate.