Image courtesy of X Combrink Zululand Nile Crocodile Research Programme Ezemvelo KZN Wildlife & University of KwaZulu Natal South Africa.

Haglöf Sweden’s wide range of mechanical caliper models is suitable for or can be adapted to fit fishery and wildlife management. With our in-house production facilities and long experience we have great capacity to customize the products and software applications. It also helps to be curious – and we are!

Together with specialized user groups and suppliers, Haglöf Sweden have developed solutions including electronic calipers and remote sensors to measure and store fish lengths and diameters at sea. Information is collected and stored digitally, and can later be transferred to handheld or PC for further processing and storing. The custom designed application is adapted to control fish stock, size and quality – both for research and for commercial reasons, and the results are aimed to achieve a better understanding of migration and movement, growth and survival rates.

The overall measurement of a fish, whether it is fork-tailed or round tailed, is taken from the snout on the upper jaw to the end of the tail. For freshwater fish, the measurements used are total length and girth. The total length is the maximum length of the fish, with the mouth closed and the tail fin pinched together. Conversely, most marine refer to the “fork length”, and scientists often use “standard length” which is to the end of the fleshy part of the body. “Standard length” has the advantage of not being affected by minor damage to the tail fin, nor does it give too much credit to a fish for the relatively light weight tail when calculating a fish’s condition.