Humane euthanasia methods for anemones
Bubble-tip anemones (Entacmea quadricolor) are common inhabitants of aquariums and zoos. But what method should be used to kill these invertebrates? For example, because they are sick or because there are too many of them in an aquarium and they threaten to upset the balance of the ecosystem?
The study systematically investigated this question. After all, animal welfare is also of central importance for invertebrates such as sea anemones.
The Bubble-tip anemone (Entacmaea quadricolor) is a marine invertebrate. Image: Zoo Zurich, Samuel Furrer
The research team of veterinarians from the University of Zurich tested three anaesthetics (magnesium chloride, MS-222 and ethanol) that are commonly used on aquatic invertebrates. None of the anaesthetics alone reliably led to death. However, all of them rendered the anemones insensitive to the effective induction of death in a second step.
A two-step procedure emerged as the most animal-friendly method of killing sea anemones: first, anaesthesia with a magnesium chloride solution, followed by freezing or immersion in formalin or ethanol. These findings help us and other zoos to ensure animal welfare when handling sea anemones until their death.
