Hawaii Division Aquatic Resources

How to Measure Fish and Invertebrates

measure fish

Fish
Measure fork length, the straight-line distance from tip of snout to middle of trailing edge of tail

measure spiny lobster

Ula (spiny lobster)
Measure carapace length, the distance from ridge between two largest spines above eyes to rear edge of carapace

measure slipper lobster

Ula papapa (slipper lobster)
Measure tail width between first and second abdominal segments

measure kona crab

Kona crab
Measure length of carapace in straight line from rostrum to middle of trailing edge of carapace

measure samoan crab

Samoan crab
Measure width of carapace at widest point

kuahonu crab

Kuahonu crab
Measure length or width of carapace at widest point, as shown above