West Coast Groundfish Observer Program Manual, Part2 - NOAA

CHAPTER 6
length is the length from the tip of the snout or jaw
(whichever sticks out most) to the end of the middle rays
of the caudal fin (See Figure 6-1 and 6-2). The only
exception to this rule is grenadier length, which is measured
from the snout to the insertion of the anal fin.
You will be given plastic measuring strips marked at
centimeter increments. The first line printed on the strip is
4.5 cm, and the space between that line and the next line is
.5 cm. Check your plastic strip on both sides to insure that
the first line is actually located 4.5 cm from the end of the
strip. Sometimes the manufacturer has cut the strip
incorrectly. Notice that the 10-centimeter increments are
not marked with a number. This is to facilitate offsetting
the strip by 10, 20, or 30 centimeters for larger fish.
Figure 6- 2: Length Measurements
6-14 1/30/2004