Mass mortality of pond-reared Carassius gibelio caused by Myxobolus ampullicapsulatus in China.

From June to August 2009, allogynogenetic silver crucian carp Carassius gibelio (Bloch) pond-cultured at the Nanquan Experimental Station, China, were found to be heavily infected with myxosporeans, which caused mortalities ranging from 33% (13/40) to 90% (36/40) in the cages. The pharynxes of infected fish were swollen, nodular, and severely damaged. Based on morphological characters and 18S small subunit ribosomal DNA sequence similarity, the myxosporean was identified as Myxobolus ampullicapsulatus. This is the first report of M. ampullicapsulatus causing mass mortality of pond-reared C. gibelio.