What does the tortoise in Yongding River mean?

The tortoise in Yongding River is a stalk, which comes from the TV series Yongzheng Dynasty and Kangxi Dynasty.

A passage in the play, the original words are "what kind of bird officer are you, the governor? There are more bastards in Yongding River than the governor".

Now this sentence is mostly used to ridicule those officials who are vegetarian and shameless.