Growth performance and survivability of the Asian seabass Lates calcarifer (Bloch, 1790) reared under hyper-saline, hypo-saline and freshwater environments in a closed aquaculture system

Abstract

Salinity is one of the most critical environmental parameters regarding fish physiology, modifying food intake and growth performance in many fish species. The present study has investigated the effects of different salinity levels on growth performance, feeding and survival of Asian seabass Lates calcarifer juveniles. Asian seabass juveniles were reared at 0 (T1), 5 (T2), 22 (T3), 36 (T4), and 42 (T5) ppt salinity. Approximately eight hundred thirty fish individuals with an average weight of 1.24±0.52 g were randomly distributed (166 fish/Tank) in 5 concrete tanks (each tank 30×6×4 ft, volume 19,122 L) for forty days. Juveniles were initially fed 42% crude protein-containing diets at a rate of 6% of their body weight per day. The results showed that salinity level had a significant effect on the weight gain (WG), average daily weight gain (ADWG), specific growth rate (SGR), feed conversion ratio (FCR), survival rate (SR), total biomass and health indices (p<0.05). The highest WG (39.11±1.49 g), ADWG (1.00±0.12 g), SGR (8.74±0.03% d-1) and lowest FCR (0.96±0.20) were observed with T3 treatment, which was significantly higher compared to other treatment groups (p<0.05). Among the health indices, the highest hepatosomatic index and viscerosomatic index were found with T3 treatment, significantly higher than the other groups (p<0.05). No significant differences were found among the treatments in terms of survival rate (p>0.05), but the maximum survival rate (98.89±0.0%) was observed in the T3 and T2 treatments. The maximum level of crude proteins (19.99±1.4%) was found in the whole-body biochemical composition of Asian seabass juveniles in the T3 treatment group. The second-order polynomial regression showed that 20 ppt salinity is optimum for the best growth of Asian seabass. Thus, the present study recommends 20 to 36 ppt salinity for the commercial farming of Asian seabass under a closed aquaculture system.

Effects of replacement of dietary fish oil with plant oil on growth performance and fatty acid composition of spinefoot rabbitfish, Siganus rivulatus

“…Fish is the cheapest source of high-quality protein fatty acids and antioxidants that can protect our body against certain diseases (Khalid et al, 2021). Fish has been an important dietary source of protein and other nutrient throughout human history (Ahmad et al, 2021;Khan et al, 2024;Hassan et al, 2024). Aquaculture is one…”

Salinity‐dependent changes in branchial morphometry and Na+, K+‐ATPase responses of euryhaline Asian sea bass, Lates calcarifer

“…Owing to its important economic role in aquaculture, Asian sea bass has been intensively studied for its growth performance (Biswas et al, 2010; Ezhilmathi et al, 2022; Khan et al, 2022; Nhan et al, 2022; Ul Hassan et al, 2021). Environmental salinity influences growth performance, digestive enzymes and oxidative stress in cultured Asian sea bass, with juvenile Asian sea bass (34 g) acclimated to 6‰–12‰ brackish water (BW) showing optimal growth performance, higher activity of the protease and lipase, as well as lower oxidative stress (Mozanzadeh et al, 2021), while smaller Asian sea bass (1.22 g) showing the best growth performance when acclimating to 20‰–36‰ seawater (Hassan et al, 2022). Although the effects of salinity on the life cycle and growth performance of Asian sea bass have been extensively investigated (Jerry, 2013), little is known about the osmoregulatory response to changing environmental salinity.…”