据唐代柳宗元的《龙城录》记载：当时江中有老蛟为害，时常吞没舟船。
O B-Time I-Time B-Person I-Person I-Person O B-Abstract I-Abstract I-Abstract I-Abstract I-Abstract O O O B-Time I-Time B-Location I-Location O B-Thing I-Thing O O O O O O O B-Thing I-Thing O