Effect of stocking density on survival rate, growth performance, swim bladder inflation and skeletal deformity of the European sea bass (Dicentrarchus labrax) larvae.

S. El-Sayed Et Al., Heba

doi:10.21608/ejabf.2021.184648

Effect of stocking density on survival rate, growth performance, swim bladder inflation and skeletal deformity of the European sea bass (Dicentrarchus labrax) larvae.

Document Type : Original Article

Author

Heba S. El-Sayed et al.

10.21608/ejabf.2021.184648

Abstract

Stocking density (STD) occupied a seniority theme in the majority of aquaculture research plans due to its impact on the interest of the farmed fish and the urgent need for future advice managing STD in marine fish hatcheries. The aim of this study was to evaluate the influence of STD (50, 75, 100 and 125 larvae l^-1) on growth parameters, survival rate, swim bladder inflation (SBI) and skeletal deformity of European sea bass (Dicentrarchus labrax)post-larvae. Two days post-hatch (dph), D. labrax larvae (2.5 mm) were stocked in 4 m³ tanks at different STDs. The results showed that larvae stocked at density 50 larvae l^-1had significantly higher total length on 60 dph compared with the other treatments which showed no significant difference among them. Bodyweight and survival rate were significantly decreased by increasing the STD. Functional swim bladder at 21 dph was inversely correlated with STD where larvae stocked at 50 and 75 l^-1 had significantly higher functional swim bladder than other investigated densities. Incidence of appearance of one skeletal deformity in the pre-haemal or caudal region significantly increased with increasing STD and was inversely correlated with SBI. On the other hand, the appearance of two skeletal deformities was only recorded in larvae stocked at 125 l^-1. The results of the current research showed that the best performance of D. labrax larvae was achieved in lower STD and that it must not exceed 75 larvae l^-1.

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