How are fish measured?

[craigj]

I've heard that nigers get around 9 inches in length, but how is that measured? Is it from the base of the tail or the end of the tail because they have a friggin long tail.

 

[grouperhead]

most measurments are usually to the fork or the tip of the tail. most measurments include tail lenght unless utherwise stated. bo

 

[pufferlover]

For considering space needed per fish in a tank tho it is measured less the tail since the tail doesn't require anything so to speak. Grouper tho is right as far as totals for use in books and reference materials.