Our venomous stingray undergoes rare surgery to remove tumour

One of our largest and most venomous aquatic creatures has undergone a rare surgical procedure to remove a life-threatening tumour.

Our in-house vets operated on the 15-year-old giant Motoro orange-spot freshwater stingray, earlier this month, after keepers noticed a rapidly-growing mass on her tail.  

Biopsy results confirmed it was a malignant tumour or cancer that was likely to spread to other organs and so the decision was made to amputate part of her tail, including the venomous barb.  

The complicated procedure saw staff draining water from the ray’s tank, before carefully netting the one-metre-long female - who weighs around the same as an average three-year-old human - and moving her to a makeshift operating table to anaesthetise.  

Zoo vet Charlotte Day, who carried out the surgery, said: “We don’t often perform general anaesthetics on fish, and large ones like this present some logistical challenges, however it was essential we treated the ray quickly before the tumour spread.”

The anaesthetic was administered with a spray pump into the ray’s gills whilst her venomous tail was held still.

“The operation went very well,” explained Charlotte. “We monitored her closely while the amputation was performed and we continued to bathe her skin to ensure it didn’t dry out. She has made a full recovery and we are really hopeful that the cancer will not return as she could live for another decade or so.”

The operation took just an hour to complete before the ray was transferred back to her tank in the Zoo’s aquarium, which is home to more than 115 different species of fish including paddlefish, coral reef fish and epaulette sharks.  

Tamara Canalejas Romera, Aquarium Interim Team Leader, said: “Even without her tail and barb she is still a very impressive stingray and is wonderful to watch during our targeted feed training sessions. We are all so pleased that the surgery was a success.”

The Motoro orange-spot ray is widespread in the Amazon Basin and the species display a distinctly colourful and high-contrast pattern of bright orange spots surrounded by deep black rings.

The species, which has an average lifespan of over 20 years, feasts on a diet of shrimps, fish, crabs and molluscs in the wild. As they have no teeth, orange-spot freshwater rays crush their food against their hard toothplates.

At the Zoo, we have four vets and two veterinary nurses and an in-house veterinary centre. Despite our gates being closed during the third lockdown of this Coronavirus pandemic, our vets and animal keepers are continuing to work hard behind the scenes to deliver the high-quality care the animals are used to.

We launched an appeal last spring to ensure the future of our work ‘saving wildlife together’. As a registered charity, we launched the BZS Appeal following the temporary closure of both our sites in Bristol in the face of the Covid-19 pandemic. To find out more about the appeal, or to make a donation, visit our appeal page.

Now faced with a third closure, the BZS Appeal is more important than ever


Now faced with a third closure, the BZS Appeal is more important than ever