一、症状及流行情况 1、早期症状 白底板病早期基本无症状，水温27-28℃以上就会出现此病，最初发现甲鱼颈部被咬烂，有人称此病为“烂头颈”，不久白底板病就爆发起来。无症状地死亡（烂头颈）即是白底板病的早期症状。 2、发病症状 外观:患病甲鱼外观较厚，腹甲呈纯白色，故 First, the symptoms and prevalence 1, early symptoms of white floor disease early asymptomatic basically, the water temperature above 27-28 ℃ will appear the disease, initially found turtle neck was bitten, some people call the disease as “rotten neck”, soon White floor disease broke out. Asymptomatic death (rotten neck) is the early symptoms of white floor disease. 2, the appearance of symptoms: the appearance of thick turtles, plastron was pure white, therefore