Nofima reports

Rapport/Report 4/2016 – English summary

Siikavuopio, Sten Ivar; Olsen, Stein Harris; Dragøy, Ragnhild; James, Philip John; Evensen, Tor Hatten; Mortensen, Atle; Olsen, Bjørn Ronald

Publication details

Publisher: Nofima AS

Issue: 4/2016

Number of pages: 8

International Standard Numbers:
Printed: 978-82-8296-352-7

Open Access: green

Links:
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In this study the effects of different stocking densities on survival, injury and weight of captive male snow crab were examined. The first experiment (I) was carried out in square plastic tanks (700 L) with stocking densities of 100 (low - L), 150 (medium - M) and 200 kg m3 (high - H) for 35 days. In a second experiment (II) snow crabs were kept at a stocking density of 50 kg m−3 and were either fed (F) or not fed (S) for the same period of 35 days. The last experiment III, was carried out with stocking densities of 25 kg m3 for 21 days with two groups, one with inactivated claw and one without rubber bands, with 3 replicates per treatment. In the first experiment mortality (H=27, M=26 and L=36 %) and occurrence of injuries (H=27, M=20 and L=16 %) was high in all groups, but not significantly different between the groups. The weight loss during the experimental period was; H=15.3, M=10.9 and L =15.5 g, and was not significantly different between the groups. In experiment 2 the mortality (F=13 % and S=14 %) and injuries were lower (F=12 % and S= 17 %). The average weight increased in the fed treatment and decreased in the starved treatments. In the last experiment there was no mortality in any of the groups and levels of injury was low (5 and 7 %). The results show that the tank system used for King crab is not suitable for long term storage of snow crab, when individual density is higher than 50 kg m3. To avoid mortality we recommend an individual density of 25 kg m3 in such system.