How to Measure Fish and Invertebrates
Fish
Measure fork length, the straight-line distance from tip of snout to middle of trailing edge of tail
Ula (spiny lobster)
Measure carapace length, the distance from ridge between two largest spines above eyes to rear edge of carapace
Ula papapa (slipper lobster)
Measure tail width between first and second abdominal segments
Kona crab
Measure length of carapace in straight line from rostrum to middle of trailing edge of carapace
Samoan crab
Measure width of carapace at widest point
Kuahonu crab
Measure length or width of carapace at widest point, as shown above