In ichthyology, the length of a fish measured from the tip of the snout to the tip of the tail. More precisely, it is the distance from the front of the jaw that is most anterior to the end of the longest caudal ray when the rays are squeezed together, excluding any caudal filaments.
This measurement is not as useful as standard length in morphometrics since it includes variability often found in the length of the caudal fin. It can be useful, however, if a fast and easy measure of fish size is needed, for example, by commercial fisheries.