Effect of Japanese sandfish (Arctoscopus japonicus) meal in paste diet for Anguilla japonica in terms of growth, feed efficiency and digestibility

In this study, the effect of replacement of high-quality fish meal (HQFM) with Japanese sandfish (Arctoscopus japonicus) meal (SFM) and the utility of a viscous culture broth of Leuconostoc mesenteroides (VCL) as binding material in paste diet for Japanese eel (Anguilla japonica) was tested in terms of growth, feed efficiency and digestibility. Four experimental paste diets contained, fish meal and binding materials as, HQFM and starch (F0, control), SFM and VCL (F1), SFM and a mixture of starch and VCL (F2) and SFM and starch (F3). Each diet was formulated to be iso-nitrogenous and iso-lipidic. Each group of 10 juvenile eels with an average initial body weight of 20 ± 2.5 g were randomly distributed into 15 tanks in triplicates and fish were fed twice daily with one of the 4 experimental paste diets for 90 days. Eels fed with diet F2 exhibited good growth performance (final mean weight; 55.3±0.67 g, WGR; 169±5%), being similar to eels (55.5±0.26g, 170±7%) fed a control diet (p>0.05). In spite of iso-nitrogenous and iso-lipidic diets, the feed efficiency of F1 and F3 were inferior to other diets and the same trend was observed in growth performance also, probably due to reduced feed intake owing to poor water stability of the feeds. It should be considered that incorporation of SFM could lead to the discharge of undesirable matters such as phosphorus into the water environment, though it would contribute to lowering production costs.Therefore, further investigations are needed to improve the quality of SFM. Keywords: Fish meal replacement, Growth performance, Iso-lipidic diet, Iso- nitrogenous diet, Leuconostoc mesenteroides, Water stability.