Desain dan Uji Kinerja Sistem Pembenihan Ikan Koi (Cyprinus rubrofuscus)

Abstract

Ikan Koi (Cyprinus rubrofuscus) merupakan komoditas ikan hias bernilai ekonomi tinggi, namun pembenihannya pada skala kecil masih menghadapi kendala dalam efisiensi sistem dan pengelolaan kualitas air. Selain itu, kajian yang mengintegrasikan karakteristik hidraulik, kualitas air, dan kinerja reproduksi dalam satu sistem pembenihan berbasis resirkulasi masih terbatas. Oleh karena itu, penelitian ini bertujuan merancang sistem pembenihan ikan Koi skala kecil berbasis resirkulasi yang mengintegrasikan pemeliharaan induk, pemijahan, dan penetasan telur, serta mengevaluasi karakteristik hidraulik, kualitas air, dan kinerja reproduksi sistem tersebut. Penelitian dilakukan menggunakan sistem resirkulasi yang terdiri atas kolam pemeliharaan induk, kolam pemijahan, kolam penetasan telur, unit filtrasi mekanis dan biologis, serta jaringan perpipaan. Evaluasi meliputi karakteristik hidraulik berupa debit aliran, kecepatan aliran, bilangan Reynolds, head loss, dan turnover rate, kualitas air berupa suhu, pH, oksigen terlarut, total ammonia nitrogen (TAN), amonia tak terionisasi (NH3), dan nitrit, serta kinerja reproduksi berdasarkan estimasi fekunditas, Fertilization Rate (FR), dan Hatching Rate (HR). Hasil penelitian menunjukkan bahwa sistem mampu mengintegrasikan proses pemeliharaan induk, pemijahan, dan penetasan telur dalam satu sistem yang beroperasi secara kontinu. Debit aliran berkisar 85,88–198,11 L/jam dengan head loss total sebesar 0,0734 m pada jalur trunk inlet dan 0,0989 m pada jalur trunk outlet, sedangkan turnover rate sebesar 0,31 kali/jam mengindikasikan bahwa sirkulasi air masih dapat dioptimalkan. Suhu, pH, oksigen terlarut, dan NH3 berada pada kisaran yang mendukung proses pembenihan, meskipun TAN dan nitrit menunjukkan kecenderungan meningkat selama penetasan telur. Sistem menghasilkan estimasi fekunditas sebesar 63.364 butir, FR sebesar 87,61%, dan HR sebesar 97,98%. Penelitian ini menghasilkan sistem pembenihan ikan Koi skala kecil berbasis resirkulasi yang mengintegrasikan seluruh tahapan awal pembenihan dalam satu sistem operasional. Temuan penelitian menunjukkan bahwa karakteristik hidraulik, kualitas air, dan kinerja reproduksi saling berkaitan dalam menentukan kinerja sistem, sehingga optimasi distribusi aliran, laju sirkulasi, dan efektivitas filtrasi menjadi aspek penting dalam pengembangan sistem pembenihan berbasis resirkulasi.

Koi (Cyprinus rubrofuscus) are ornamental fish with high economic value; however, small-scale breeding still faces challenges in system efficiency and water quality management. Furthermore, studies that integrate hydraulic characteristics, water quality, and reproductive performance within a single recirculating aquaculture system remain limited. Therefore, this study aims to design a small-scale recirculating Koi breeding system that integrates broodstock rearing, spawning, and egg hatching, and to evaluate the system’s hydraulic characteristics, water quality, and reproductive performance. The study was conducted using a recirculating system consisting of a broodstock rearing pond, a spawning pond, an egg hatching pond, mechanical and biological filtration units, and a piping network. The evaluation included hydraulic characteristics such as flow rate, flow velocity, Reynolds number, head loss, and turnover rate; water quality parameters such as temperature, pH, dissolved oxygen, total ammonia nitrogen (TAN), un-ionized ammonia (NH3), and nitrite; and reproductive performance based on estimated fecundity, fertilization rate (FR), and hatching rate (HR). The results of the study show that the system is capable of integrating broodstock maintenance, spawning, and egg hatching into a single, continuously operating system. The flow rate ranged from 85.88 to 198.11 L/h with a total head loss of 0.0734 m in the inlet trunk line and 0.0989 m in the outlet trunk line, while the turnover rate of 0.31 times/hour indicates that water circulation can still be optimized. Temperature, pH, dissolved oxygen, and NH3 were within ranges supportive of the breeding process, although TAN and nitrite showed an upward trend during egg hatching. The system yielded an estimated fecundity of 63,364 eggs, a fertilization rate (FR) of 87.61%, and a hatching rate (HR) of 97.98%. This study resulted in a small-scale recirculating Koi fish hatchery system that integrates all early stages of hatchery operations into a single operational system. The findings indicate that hydraulic characteristics, water quality, and reproductive performance are interrelated in determining system performance; therefore, optimizing flow distribution, circulation rate, and filtration efficiency are critical aspects in the development of recirculating hatchery systems.