Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-27T10:29:50.322Z Has data issue: false hasContentIssue false
  • English
  • Français

Electrical stunning of edible crabs (Cancer pagurus): from single experiments to commercial practice

Published online by Cambridge University Press:  01 January 2023

B Roth  and
E GrimsbØ
B Roth*
Affiliation:
Nofima, Department of Processing Technology, PO Box 8034, N-4068 Stavanger, Norway
E GrimsbØ
Affiliation:
University of Bergen, Department of Biology, Thormøhlensgate 53, Box 7803, N-5020 Bergen, Norway
*
* Contact for correspondence and requests for reprints: Bjorn.Roth@nofima.no
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

To determine the optimal electrical stunning conditions for edible crabs (Cancer pagurus) their impedance was investigated along with currents with the potential to render the animal insensible within 1 s. This information was used to develop a commercial stunner and determine conditions that both stun and kill the animals instantaneously. Results show that the crabs’ impedance is dependent on the current frequency with the optimum outcome seen at net frequencies of 50–60 Hz. The proportion of animals stunned was dependent on the potential difference with 220 V required to stun an animal unconscious within 1 s. Any attempts to kill the crab with asphyxia after a 10-s exposure to electricity failed as 30% of crabs recovered within an hour. A thermal shock, pre- or post-stunning prevented this recovery. Autotomy was not avoided and approximately 4–7% of crabs lost one or more appendage. Electricity caused localised over-heating, but a current of 10-s duration did not cause heating of the carapace. We conclude that electrical stunning used in combination with a thermal shock may stun and kill the animal instantaneously.

Keywords

animal welfarecrabcrustaceanelectricityslaughterstunning
Type
Articles
Information
Animal Welfare , Volume 25 , Issue 4 , November 2016 , pp. 489 - 497
Copyright
© 2016 Universities Federation for Animal Welfare

References

Anon 2009 Lov om dyrevelferd LOV-2009-06-19-97. §1. Department of Agriculture and Food: Norway. https://lovdata.no/dokument/NL/lov/2009-06-19-97. [Title trans-lation: Law of animal welfare]Google Scholar
Baker, JR 1955 Experiments on the humane killing of crabs. Journal of the Marine Biological Association of the United Kingdom 34:15–24. http://dx.doi.org/10.1017/S0025315400008572CrossRefGoogle Scholar
Baker, JR and Dolan, MB 1975 Experiments on the humane killing of lobsters (Homarus vulgaris) and crabs (Cancer pagurus). Part 2. The exposure of lobsters to electric shock before boiling. Scientific Papers of the Humane Education Centre 1: 1–24Google Scholar
Baker, JR, Dolan, MB and Coxhill, J 1975 Experiments on the humane killing of lobsters (Homarus vulgaris) and crabs (Cancer pagu-rus). Part 3. The exposure of lobsters to electric shock before boiling. Scientific Papers of the Humane Education Centre 1: 1–11Google Scholar
Chiba, M, Hamaguchi, M, Asa, T, Tokuno, T and Chichibu, S 1990 In vivo P-NMR analysis of the electric anesthetized loach (Corbis biswae). Comparative Biochemistry and Physiology 97A: 385-389CrossRefGoogle Scholar
Edwards, E 1979 The Edible Crab and its Fishery in British Waters. Buckland Foundation Books: Bath, UKGoogle Scholar
EFSA 2004 Scientific Report of the Scientific Panel for Animal Health and Welfare on a request from the Commission related to welfare aspects of animal stunning and killing methods. EFSA Journal 45: 1-29Google Scholar
EFSA 2005 Opinion of the Scientific Panel on Animal Health and Welfare on a request from the Commission related to aspects of the biology and welfare of animals used for experimental and other scientific purposes. EFSA Journal 292: 1–46Google Scholar
Elwood, RW and Appel, M 2009 Pain experience in hermit crabs? Animal Behaviour 77: 1243–1246. http://dx.doi.org/10.1016/j.anbehav.2009.01.028CrossRefGoogle Scholar
Elwood, RW, Barr, S and Patterson, L 2009 Pain and stress in crustaceans? Applied Animal Behaviour Science 118: 128–136. http://dx.doi.org/10.1016/j.applanim.2009.02.018CrossRefGoogle Scholar
Erikson, U, Lambooij, B, Digre, H, Reimert, HGM, Bondo, M and van der Vis, H 2012 Conditions for instant electrical stun-ning of farmed Atlantic cod after de-watering, maintenance of unconsciousness, effects of stress, and fillet quality: A comparison with AQUI-S (TM). Aquaculture 324: 135–144. http://dx.doi.org/10.1016/j.aquaculture.2011.10.011CrossRefGoogle Scholar
Grimnes S and Grøttan Martinsen Ø 2008 Bioimpedance and Bioelectricity Basics. Academic Press: Oxford, UKGoogle Scholar
Lambooij, B, Digre, H, Erikson, U, Reimert, H, Burggraaf, D and van de Vis, H 2013 Evaluation of electrical stunning of Atlantic cod (Gadus morhua) and turbot (Psetta maxima) in seawa-ter. Journal of Aquatic Food Product Technology 22: 371–379. http://dx.doi.org/10.1080/10498850.2011.654047CrossRefGoogle Scholar
Lambooij, B, Gerritzen, MA, Reimert, H, Burggraaf, D, Andre, G and van de Vis, H 2008 Evaluation of electrical stun-ning of sea bass (Dicentrarchus labrax) in seawater and killing by chilling: welfare aspects, product quality and possibilities for implementation. Aquaculture Research 39: 50–58. http://dx.doi.org/10.1111/j.1365-2109.2007.01860.xCrossRefGoogle Scholar
Lambooij, B, GrimsbØ, E, van de Vis, JW, Reimert, HGM, Nortvedt, R and Roth, B 2010 Percussion and electrical stun-ning of Atlantic salmon (Salmo salar) after dewatering and subse-quent effect on brain and heart activities. Aquaculture 300: 107–112. http://dx.doi.org/10.1016/j.aquaculture.2009.12.022CrossRefGoogle Scholar
Magee, B and Elwood, RW 2013 Shock avoidance by discrimi-nation learning in the shore crab (Carcinus maenas) is consistent with a key criterion for pain. Journal of Experimental Biology 216:353–358. http://dx.doi.org/10.1242/jeb.072041CrossRefGoogle ScholarPubMed
Ogawa, M, Ito, LS and de Abreu Melo, FE 2007 Electric paralysation and reduction of weight loss in the processing of round-cooked spiny lobsters. Ciencia E Tecnologia de Alimentos 27:125–129. http://dx.doi.org/10.1590/S0101-20612007000100022CrossRefGoogle Scholar
Robb, D 1999 The Humane Slaughter of Crustacea: Electrical Stunning. Department of Food Animal Science, University of Bristol, Langford, UKGoogle Scholar
Roth, B and ⊘ines, S 2010 Stunning and killing of edible crabs (Cancer pagurus). Animal Welfare 19: 287–294Google Scholar
Roth, B, Stien, LH, GrimsbØ, E, Slinde, E, Foss, A and Nortvedt, R 2010 Electric stimulation and stunning of Atlantic salmon muscle and the effect of flesh quality. Aquaculture 301: 85–90. http://dx.doi.org/10.1016/j.aquaculture.2010.01.008CrossRefGoogle Scholar
Schwan, HP 1963 Determination of biological impedances. In: Nastuk, WL (ed) Physical Techniques in Biological Research pp 323–407. Academic Press: New York, USA and London, UK. http://dx.doi.org/10.1016/b978-1-4831-6743-5.50013-7CrossRefGoogle Scholar
Schwan, HP 1984 Electrical and acoustic properties of biological materials and biomedical applications. IEEE Transactions on Biomedical Engineering 31: 872–878. http://dx.doi.org/10.1109/TBME.1984.325251CrossRefGoogle ScholarPubMed
Schwan, HP 1994 Electrical properties of tissues and cell suspensions mechanisms and models. 16th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 3-6 November 1994, Baltimore, Maryland, USAGoogle Scholar
Šel, D, Cukjati, D, Batiuskaite, D, Slivnik, T, Mir, LM and Miklavčič, D 2005 Sequential finite element model of tissue elec-tropermeabilization. Biomedical Engineering 52: 816–827Google Scholar
Zivotofsky, AZ and Strous, RD 2012 A perspective on the electrical stunning of animals: Are there lessons to be learned from human electro-convulsive therapy (ECT)? Meat Science 90:956–961. http://dx.doi.org/10.1016/j.meatsci.2011.11.039Google ScholarPubMed