Internationally pioneering work: moray eel under the knife

On Monday, 9 November 2020, veterinarian Henk Luten, curator/biologist Max Janse and the zookeeper team from the Ocean successfully carried out internationally pioneering work.  A moray eel, at least twenty years old and a staggering 1.48 metres long, had a skin infection on its head. At present, there is hardly any experience with operating on tropical saltwater fish worldwide. Another successful operation was performed on a fish in our zoo eight years ago—coincidentally the same animal, but for a different ailment at the time.

Thorough preparation

A team of eight people was compiled to make the operation as efficient as possible. The animal was carefully placed in a container with saltwater and anaesthetic. Once sedated, the 1.48-metre-long moray eel was placed in a half PVC pipe on the operating table and covered with wet cloths. A hose provided a steady stream of oxygen-rich water and anaesthetic over the gills through the mouth, allowing the moray eel to continue to breathe properly.

Concentration

Equipped with gloves and a headlight to ensure a clear view at all times, veterinarian Henk Luten went to work with extreme concentration. The moray eel's skin was infected around the eyes and upper jaw. Luten quickly biopsied the infected areas, and a culture test was performed on the samples to determine what type of bacteria or fungus was affecting the animal. During the operation, the vet noted the presence of healthy pink repair tissue—a favourable development for the animal's recovery.

Sharing knowledge with the world

International knowledge and experience with operating on tropical saltwater fish are still in their infancy. "We learn a lot from days like this, and we share that with the world," said the vet. Just like modern zoos, large public aquariums are working together on an international level with increasing intensity. Several international veterinarians were consulted in preparation for this operation; the anaesthesia was particularly challenging.

The patient is recovering well

The moray eel is doing well immediately after the operation. The animal is quietly recovering from the anaesthetic and will spend the next few days in quarantine behind the scenes. Based on the biopsy results, the team will determine the next steps. The options include treatment with specific medication, another operation or just rest. Our goal is to have the animal visible to the public again, but for now, the moray eel will remain in the fish hospital.