According to Wikipedia (2016), quoting T. Ryan Gregory (2008), quoting D. E. Comings (1972) who may or may not quoting anyone because he said it in a book instead of the Internet, the amphiuma has 25 times as much DNA as a human.

I have no idea how this is measured. It seems to me that it has to be based on a body size ratio, because an adult amphiuma averages 450g and an adult human averages 65,000g … a tad bit more. So, if it’s ratio based, is it amount of DNA material vs body mass? DNA material vs the rest of a cell? If so, which type of cell? DNA material vs material in the nucleus?

Maybe it’s just a chromosome count. Maybe it’s total amount of genes. Maybe it’s based on the length of the DNA “threads”. Maybe it’s a count of the total number of atoms in all of the DNA in an average representational nucleus.

Anyway, this is why you either need to be more careful when quoting things or put your source material where everyone can get it.