Abstract:
The crude 0.01 N HCl extract of kelp Ascophyllum nodosum inhibited Vibrio alginolyticus, V. parahaemolyticus, V. fluvialis and V. cholerae causing vibriosis disease in spotted babylon Babylonia areolata. The result on minimal inhibition concentrations MIC of four species were 16, 18, 16 and 22 mg mL-¹, respectively and minimal bactericidal concentrations MBC were 46, 52, 50 and 58 mg mL-¹, respectively. Kelp also presented effect on vibriosis resistance and growth of spotted babylon. On the vibriosis resistance experiment, 120 spotted babylon were divided into four groups with triplicates. Each group was fed on seven days with kelp extract supplement in diet 0%, 1.5%, 3.0% and 4.5% (w w-¹). Median lethal dose LD50 of V. alginolyticus was intramuscular injected in each spotted babylon. Then, each group was afterward raised on seven days. The result on percent survival rate of each group were 16.67 ± 11.55b, 46.67 ± 5.77a, 43.33 ± 5.77a, and 46.67 ± 5.77a, respectively with significant difference (P < 0.05). On the growth performance experiment, 150 spotted babylon were divided into five groups with triplicates. Each group was fed on 30 days with kelp meal supplement in diet 0%, 2.5%, 5.0% and 10.0% (w w-¹]. The result on total shell length of each group were 21.11 ± 0.34c, 21.23 ± 0.20b, 21.17 ± 0.20bc], 21.11 ± 0.16c and 22.61 ± 0.14a, mm, respectively with significant difference (P < 0.05). The result on wet body weight of each group were 2.17 ± 0.03b, 2.17 ± 0.02b, 2.14 ± 0.02c, 2.10 ± 0.06d and 2.98 ± 0.12a g, respectively with significant difference (P < 0.05). This study presents the potential of A. nodosum as diet supplement and should be continuously studied for application of B. areolata culture.
