man rename
Basically - "rename <expression> <replacement> <file>...", and the ... is for multiple files
Code:
...
DESCRIPTION
rename will rename the specified files by replacing the first occur‐
rence of expression in their name by replacement.
...
so your sample would imply that "rename TaeCsp2AS_1635 TaeCsp2AS_1635_ TaeCsp2AS_1635*"
should do the job.