Stunning of edible crustaceans to reduce sensory perception prior and during slaughter is an important topic in animal welfare. The purpose of this project was to determine how neural circuits were affected during stunning by examining the physiological function of neural circuits. The central nervous system circuit to a cardiac or skeletal muscle response was examined. Three commercially important crustacean species were utilized for stunning by immersion in an ice slurry below 4 °C and by electrocution; both practices are used in the seafood industry. The blue crab (Callinectes sapidus), the red swamp crayfish (Procambarus clarkii), and the whiteleg shrimp (Litopenaeus vannamei) responded differently to stunning by cold and electric shock. Immersion in ice slurry induced sedation within seconds in crayfish and shrimp but not crabs and cardiac function was reduced fastest in shrimp. However, crabs could retain a functional neural circuit over the same time when shrimp and crayfish were nonresponsive. An electroshock of 10 s paralyzed all three species and subsequently decreased heart rate within 1 min and then heart rate increased but resulted in irregularity over time. Further research is needed to study a state of responsiveness by these methods.
Digital Object Identifier (DOI)
Deutscher Akademischer Austausch Dienst (DAAD) German Academic Exchange Service, RISE Program (Research Internships in Science and Engineering) (K.W.); Aquaculture Research Center, Kentucky State University (A.R. and L.F.) and personal funds (R.L.C.). Funding for this work was provided by a KBrIN summer research fellowship from the University of Kentucky (M.M. and N.D.).
The following are available below as the additional file and online at http://www.mdpi.com/2076-2615/8/9/158/s1,
Video S1. Whole shrimp in ice slurry. A live intact shrimp is placed in the ice slurry and within a second the animal starts to repetitively tail flip.
Video S2. Abdomen only in ice slurry. The head of the shrimp was cut off and the abdomen of the shrimp is rapidly removed from the body and placed in the ice slurry. The isolated abdomen starts to tail flip on its own as if attached to the intact animal. These rapid decapitated shrimp and removal of the abdomen experiments were performed at KSU.
Video S3. Abdomen with motor roots cut in ice slurry. The head of the shrimp was cut off and the abdomen of the shrimp is rapidly removed from the body. The motor nerve roots were rapidly cut along each side of the abdomen before placing the abdomen in the ice slurry. The isolated abdomen does not tail flip on its own when the nerve roots are cut. These experiments were performed at KSU.
Weineck, Kristin; Ray, Andrew J.; Fleckenstein, Leo J.; Medley, Meagan; Dzubuk, Nicole; Piana, Elena; and Cooper, Robin L., "Physiological Changes as a Measure of Crustacean Welfare under Different Standardized Stunning Techniques: Cooling and Electroshock" (2018). Biology Faculty Publications. 149.