Abstract

In addition to making visual health assessments of captive cephalopods, occasionally the need to utilize anesthesia in cephalopods becomes important for minor surgical procedures or for diagnostic purposes. In addition, higher doses of anesthetic agents can be used for humane euthanasia of cephalopods.

Several agents have been used historically, including: magnesium chloride¹, ethanol and urethane (ethyl carbamate). Since urethane is a noted carcinogen² its use in the aquarium should be avoided whenever possible. Our main focus will be to share our experiences with dose/effect results for both ethanol and magnesium chloride as anesthetic agents. Procedures using the above anesthetic agents in two commonly used cephalopods will be demonstrated in the Cuttlefish Sepia officinalis and in the California mud flat octopus Octopus bimaculoides. Factors to be considered when using anesthetic agents are: strain differences in cephalopods, age, sex, overall health condition of an individual animal, time length of the procedure or surgery, ambient temperature, and water conditions.

When working with cephalopods minimal handling of the animals is essential in preventing abrasions since the outer epithelial layer is only one cell thick, making their skin very delicate. Some common anatomical structures used for diagnostic procedures will be noted. The goal of our presentation will provide another useful tool in the overall colony health of captive and laboratory raised cephalopods.

References

1.  Messenger JB, M Nixon, KP Ryan. 1985. Magnesium chloride as an anesthetic for cephalopods. Comp. Biochem. Physiol. 82C:203-205.

2.  Flecknell PA. 1987 Special Techniques. In: Laboratory Animal Anesthesia: An introduction for research workers and technicians. San Diego: Academic Press, Inc., P.40.