Optimal Stocking Density with the Provision of Self‐feeders for Striped Knifejaw, Oplegnathus fasciatus (Temminck and Schlegel 1844)

Abstract

To determine the optimal stocking density, three densities of 5 (SD5), 10 (SD10), and 15 kg/m3 (SD15) were used to culture striped knifejaw, Oplegnathus fasciatus, for 10 wk. A total of 10, 20, or 30 juveniles with mean weights of approximately 96 g were stocked into one of nine 300‐L tanks (with an initial water volume of 200 L) and fed with commercial feed via self‐feeders. The fish were sampled at 4 and 8 wk, and the stocking density was maintained by adjusting the water volume of the tanks. The final body weights in SD10 and SD15 were 183.8 and 178.9 g, respectively, which were significantly higher than 161.7 g in SD5 (P< 0.05). However, there was no significant difference between the SD10 and SD15 (P > 0.05). A similar trend was observed in the specific growth rate among the treatments. Feed efficiency and the lipid retention efficiency were both significantly higher in SD10 than that in SD5. The plasma levels of cortisol, glucose, and total protein were similar among the treatments. These results clearly suggest that densities of 10 and 15 kg/m3 can be used to improve the growth performance of striped knifejaw, O. fasciatus, when fed with a self‐feeder.

Machinery feeding development for sustainable aquaculture: Self-feeding system

“…Indoor and outdoor Individual and group Sevenband Grouper (Epinephelus septemfasciatus) [29] Indoor Group European sea bass (Dicentrarchus labrax , L .) [30] Indoor Group Striped Knifejaw (Oplegnathus fasciatus) [31] Outdoor(Cage) Group Tilapia (Tilapia aurea) [32] Outdoor Group Pirarucu (Arapaima gigas) [33] Laboratorium Individual and group Oreochromis niloticus and Sarotherodon melanotheron [5] Indoor and Outdoor individual and group Nile tilapia (Oreochromis niloticus) [34] Indoor Group Tambaqui (Colossoma macropomum) The European sea bass (Dicentrarchus labrax, L .) became the most common (28.57%) fish species used in self-feeding system field study and the second most common group was Rainbow trout (Oncorhynchus mykiss) with percentage of 21.43% (Table 2).…”

“…In addition to use the feeding behavior approach, the assessment of more than one treatment in different sampling periods (seasonal variation) may help in the interpretation of physiological behavior responses [4,5] . Other parameters which commonly evaluated were circadian rhythm and loco motor activity [15,16,34,21,12, 40} , feeding behavior [1,4,6,20,36,38] , stress condition [30,17] . Besides that, the type of rearing condition also was assessed as shown in Table 1.…”

Influence of Manila clam aquaculture on rates and partitioning of organic carbon oxidation in sediment of Keunso Bay, Yellow Sea

“…In contrast, high stocking densities cause stress from competition for food and space and pathogen infestation, which can lead to mass mortality of aquaculture organisms (Wilber & Wilber 1991, Dittel et al 1995, Sheen 2000. Numerous studies have been carried out to determine the optimal stocking density in farm operations to maximize production rates (Wu et al 1994, Azim et al 2001, De Silva 2003, Biswas & Takii 2017. From a biogeochemical viewpoint, stocking density is also the main factor in controlling the envi-ronmental impact of a Manila clam farm.…”