Influence of different feeding rates of polychaete worms, Eulalia viridis (Annelida, Polychaeta), on the gonad development of male Penaeus semisulcatus (Decapoda, Dendrobranchiata) under captive conditions

Abstract

Penaeus semisulcatus is a large growing species, attaining a maximum size of about 250 mm in total length. It is more resistant to white spot syndrome virus (WSSV) than other cultivable penaeid shrimps, which makes it a potential candidate for culture. The present study evaluated the influence of a different feeding rate of polychaete worms on the gonad development of male P. semisulcatus under captive conditions. P. semisulcatus sub-adults were obtained in the wild. The shrimps were fed with three different concentrations of polychaete worms, viz., ad libitum (T1), 5% of body weight (BW) (T2) and 10% BW (T3), and fresh sardines were fed as a Control (C) diet, all for a period of 60 days. Sampling was done once in 15 days and the bio-growth parameters were recorded. The gonads were harvested for histological analysis. The maximum weight gain (10.19 g), mean weight gain percentage (85.20%), mean daily growth rate (DGR) (0.169833) and mean specific growth rate (SGR) (0.45) were found in shrimps fed with the polychaete worm diet at 5% BW. The estimated bio-growth parameter values were statistically significant when analysed using One way ANOVA (). Histological sections of the testis showed variations in the development of the gonad between the treatments with different feeding rates during the 60 days trials. Indeed in all aspects, the development was higher in shrimps fed with polychaete worms at 5% BW. It can be concluded that feeding polychaete worms at 5% BW created a regime able to improve growth rates, gonad maturation, and quality in the development of the captive male brood stock.