The correct pronunciation of 龟裂

Hi ChinesePod team, my question is this:
I found this words randomly and as I know 龟 is pronouns as gui1, but why in this case is called jun1?

Hi Eddie,

There are certain words in Chinese that change pronunciations in different terms or meanings. Here, as you mentioned, 龟 normally is pronounced as guī in 乌龟 [wūguī] (turtle) . But in this term 龟裂 (crack), it would be pronounced [jūn liè].