Valorisation of discard fish and fish wastes fermented with lactic acid bacteria have potential biotechnological application to produce high quality animal food. Five lactic acid bacteria strains naturally present in fish (Lactobacillus brevis, Lactobacillus plantarum, Pediococcus acidilactici, Streptococcus spp. and Enterococcus gallinarum) and formic acid were evaluated for the production of fish silages made from two discard fish species [Equulites klunzingeri (Klunzinger's pony fish-marine fish) and Carassius gibelio (Gibel carp-freshwater fish)]. Chemical (pH, TBA and non-protein nitrogen analyses) and microbiological (total aerobic and anaerobic microorganism counts, lactic acid bacteria, fungi, total coliform and pathogen bacteria) aspects were investigated during maturation process in silages groups. Gibel silages ripened in a short time (in 3 days) than silages prepared with Equulites klunzingeri (in 2 weeks). A slight increase in non-protein nitrogen value (0.4-0.7 g 100 g(-1)) was detected in all silage groups. TBARs values of formic acid groups were significantly higher than the fermented groups during the 3-week period. Fish silages prepared with Lactobacillus brevis and Streptococcus spp. had the highest lipid stability in all fermented groups according to TBA values. No pathogen bacteria were detected in all silage groups. According to the chemical and microbiological evaluations on silages, these lactic acid bacteria can be used successfully as starter cultures in order to produce high quality animal food from discard fish.