Kinerja Produksi dan Usaha Pendederan Kerapu Cantang pada Sistem Flow-Through dengan Perbedaan Pergantian Air Harian

Abstract

Penerapan pergantian air yang optimal dapat meningkatkan kinerja produksi dan usaha pendederan ikan kerapu. Penelitian bertujuan menganalisis persentase pergantian air harian yang berbeda untuk menghasilkan kinerja produksi dan usaha pendederan ikan kerapu cantang (Epinephelus fuscoguttatus >< E. lanceolatus) terbaik yang dipelihara menggunakan sistem flow-through. Terdapat tiga perlakuan dan tiga kali pengulangan yang diujikan, yaitu pergantian air 100%, 200%, dan 300 %/hari. Benih ikan kerapu cantang dipelihara dalam bak fiber bundar dengan volume 1 m3 yang dikumpulkan di dalam hatchery dengan ukuran tebar 12,7±0,22 cm. Benih ikan kerapu dipelihara dengan kepadatan 20 ekor/m3 selama 40 hari dan diberi pakan berupa pelet dengan protein 48% sebanyak 3 kali sehari secara at satiation. Hasil penelitian menunjukkan bahwa perlakuan pergantian air 300 %/hari memberikan kinerja produksi lebih baik, dengan tingkat kelangsungan hidup 90%, rasio konversi pakan 1,46, laju pertumbuhan panjang spesifik sebesar 1,05±0,04 %/hari, laju pertumbuhan panjang mutlak sebesar 0,16±0,01 cm/hari, panjang panen 17,3±0,38 cm, serta kinerja usaha terbaik dengan keuntungan tertinggi sebesar Rp20.804.102 per tahun, R/C rasio tertinggi 1,18, dan payback period terendah 8,72 tahun.

The optimal application of water changes can enhance production performance and the business of grouper nurseries. This research aims to analyze the different daily water change percentages for achieving the best production performance and nursery business for cantang grouper (Epinephelus fuscoguttatus >< E. lanceolatus) reared using a flow-through system. There were three treatments with three replications were tested; 100%, 200%, and 300 %/day. Cantang grouper fry are reared in round fiber tanks with a volume of 1 m3 which are collected in the hatchery with a stocking size of 12.7±0.22 cm. Grouper fry were reared at a density of 20 fish/m3 for 40 days and fed with pellets containing 48% protein, three times a day at satiation. The results showed that the 300%/day water change treatment provided better production performance, with a survival rate of 90%, a feed conversion ratio of 1.46, a specific length growth rate of 1.05±0.04 %/day, a absolute length growth rate of 0.16±0.01 cm/day, harvest length of 17.3±0.38 cm, as well as the best business performance with the highest profit of IDR 20,804,102 per year, the highest R/C ratio of 1.18, and the lowest payback period of 8.72 years.