Introduction
Snubnose pompano (Trachinotus blochii) is a new potential aquaculture species in Saudi Arabia and, as such, is of economic importance in the Red Sea region (Young et al., 2021a). However, there is a lack of information on the larviculture of the snubnose pompano in high salinity conditions outdoors. On the coastline of Jeddah, West Saudi Arabia, the salinity of seawater is 42 to 45‰ during the producing period. Based on our previous records (Young et al., 2021b), we noticed that high salinity (42‰) cause fry deformity indoors. Moreover, due to high salinity, the reproduction rate of live food reduced to lower than the rates required for culture. Therefore, outdoor systems might prove more successful in raising fry. However, there is a lack of information on the larviculture of the snubnose pompano in high salinity conditions outdoors. Therefore, this study was designed to improve our understanding of outdoor larviculture of snubnose pompano under high salinity conditions.
Methods
This study estimated the survival rate, growth performance, and cost of the larviculture of snubnose pompano outdoors at different levels of salinity (33‰, 36‰, 39‰, and 42‰) at 32.3°C–36.0°C. Experiments were conducted in triplicates with 1000 larvae per outdoor tank. The control group was maintained at salinity level of 42‰ indoors. Eighteen hours after hatching, the larvae were transferred outdoors and maintained at different salinity levels (33‰, 36‰, 39‰, and 42‰). The survival rate and growth performance of raising larvae were monitored from day 1 to day 45.
Results
Table 1. Survival rate and growth performance of snubnose pompano larvae fed on microalgae, rotifers, and 120 μm of commercial feed at different salinity levels at 32.3°C–36.0°C
Discussion
Young et al. (2021b) reported that the survival rate of snubnose pompano larvae was 32%–36% in the indoor conditions exposed to salinity levels between 33‰–39‰. Under outdoor conditions in this study, the survival rate of snubnose pompano larvae was 19.3%–26.5%. In this study, the maximum salinity tolerated by snubnose pompano in larviculture was 39‰. Notable, Young et al. (2021b) noticed that high salinity (42‰) causes snubnose pompano fry deformity indoors. In this study, we observed that snubnose pompano fry was not shown deformity in 33‰ -39‰ outdoor, yet 42‰ still cause snubnose pompano fry deformity outdoors. Our results indicate that the larviculture of snubnose pompano is feasible in high salinity conditions in outdoors.
References
Young, B.C. and Alfaggeh, R.H. 2021a. Entirely farm-raised Snubnose pompano (Trachinotus blochii) under high salinity in Saudi Arabia. Isr J Aquac 73:1546070.
Young, B.C., Alfaggeh, R.H. and AlMoutiri, I. 2021b. Larviculture of Snubnose pompano under conditions of high salinity. N Am J Aquac 83:38-40.