The composition of intestinal lactic acid bacteria (LAB) in silver carp (Hypopthalmichthys molitrix) in Gheshlaghdam Lake was analyzed based on morphology and biochemical tests in December 2009 to March 2010. Most isolates were Gram-positive, non motile and catalase-negative bacilli that did not produce gas from glucose. Growth at 15°C was positive for all isolates, while it was positive for some isolates at 45°C.The results of the carbohydrate fermentation tests were positive reactions for most sugars. The results show that in winter, the predominant LAB were Lactococcus plantarum, Lactococcus raffinolactis and Lactococcus lactis, respectively.

Key words: Silver carp, lactic acid bacteria, intestine, Gheshlaghdam Lake.