Rabbitfish (Siganus guttatus) culture in floating net cage with different stocking densities

Abstract

Rabbitfish (Siganus guttatus) is a schooling species which potential for being farmed in high density, however the information about stocking density of this species remain rare. This study was aimed to evaluate growth, survival rate, FCR, stress level and osmoregulation of Rabbitfish under different stocking densities. The tested fishes were the second generation (G2) of Rabbitfish that produced by hatchery outdoor of Research Institute of Coastal Aquaculture and Fisheries Extension, Maros, Indonesia. There were two stages of this study: the first stage was fingerling production. The seeds of Rabbitfish with average of length 6.2±0.8 cm and body weight 4.7±1.9 g/ind were reared in total of 12 units of 1 x 1 x 1 m3 floating net cage for 90 days. The stocking densities were 50, 100, 150 and 200 ind/m3. The second stage of this study was fish growing, where the tested fishes were cultivated with stocking density of 100, 150 and 200 ind/m3 in the same size of net as the first stage. The result of first stage showed that stocking density did not significantly affect growth rate of Rabbitfish fingerling. However, survival rate at stocking density of 50 (99.33±1.15%) and 100 ind/m3 (98,33±0,58%) were higher compared to stocking densities 150 and 200 ind/m3 (94.89±1.39 and 93.50±2.65%, respectively). The result of second stage showed that stocking density of 100 ind/m3 resulted significant growth, survival rate and FCR compared to that observed on 150 and 200 ind/m3. The fish stocked with density of 100 ind/m3 had length (18.6±0.3 cm), weigh (121.8±9.8 g/ind.), survival rate (92.0±2.6%) and FCR (4,41±0,43). Whereas, the result for fish stocked with 150 ind/m3 were 17.6±0.3 cm, 107.1±7.0 gram, 86.2±7.1 % and 5.15±0.59, respectively, and 200 ind/m3 were 16.9±0.2 cm, 96.5±5.9 gram, 82.2±2.3 % and 5,64±0,6, respectively. High stocking density might trigger stress on Rabbitfish and lower blood osmolality found on stocking density of 150 ind/m3 (490.00±59.77 mOsm/kg) and 200 ind/m3 (469.00±23.30 mOsm/kg) compared to that observed on density of 100 ind/m3 (501.67±23.50 mosm/kg). During hypo-osmotic condition, the osmoregulation was not regulated by stocking density as indicated by blood osmotic performance levels <1, which was 0.37 mOsm/kg (100 ind/m3) and 0.33 mOsm/kg (for 150 and 200 ind/m3).

Effects of Iodine Treatment on the Development of Eggs and Larvae of Rabbitfish (Siganus guttatus Bloch, 1787)

“…In the salinity range from 14 to 37 ‰, rabbitfish eggs have a survival rate of over 50 %, eggs and larvae have the highest survival rate at a salinity of 16 ‰ (Stattin, 2012). According to Rachman Syah et al (2020), most of the parameters for water quality were still at the viable state for the life and growth of rabbitfish, S. guttatus were temperature: 25.2-33.7°C; salinity: 26.9-37.2 ppt; pH: 7.5-9.2; DO: 3.3-6.9 mg/L. So, the environmental factors of carrying out studies on the influence of iodine concentration and washing time on the efficiency of broodstock (S. gustatus) including temperature, pH, DO, salinity, NH 4 + /NH 3 (Table 1) were maintained stably and within the threshold for embryo and larval development of rabbitfish.…”

Growth performances and gonadal development of golden rabbitfish, Siganus guttatus fed with two types of floating diets in sea cages

“…In several countries including Indonesia and Philippine, one of Siganid fish, golden rabbitfish, Siganus guttatus has been an emerging species for aquaculture [1,4] despite very limited seed production from hatchery. Besides its high market value, rabbitfish has various attributes to support its aquaculture development including their tolerances to a wide range of salinities and high density [5,6]. As herbivorous fish, rabbitfish can utilize seaweed for freshfeed [4] and artificial diet formulated with alternative plant feed ingredients [7][8][9].…”

The potential role of marine macroalgae Padina pavonica on growth performance, histological status, and resistance of the rabbitfish Siganus rivulatus to Pseudomonas anguilliseptica bacteria

“…It has received attention from researchers for its utilization as an antibiotic, antioxidant, antimicrobial, hepatoprotective, hypo-allergenic, anti-inflammatory, antidiabetic, and as a good source of food, fodder, plant growth promoter and bio-fertilizer (Ansari & Ghanem, 2019) Rabbitfish, Siganus rivulatus, is one of the tasty white meat, and it is a herbivore, responsive to artificial food, and easy to spawn so that demand for fry stocks can be met through hatcheries Syah et al, 2007). Rabbitfish can survive in high stocking density and quickly adapt to salinity ranges between 5-40 g/L; hence, it has become a candidate promising species to be cultivated (Nelson et al, 1992;Darsono, 1993;Teitelbaum et al, 2008;Gonzales et al, 2018;Seale and Ellies, 2019;Syah et al, 2020 ).…”