Learning from the Twins – Dolphin Necropsies on Two Striped Dolphins
Written by Ashley Postlewhite, Nov 30 2022
Learning from the Twins - Dolphin Necropsies on Two Striped Dolphins
On the 18th of July, the Marine Dynamic team partnered up with Chris Wilkinson from the University of Pretoria’s MIC whale unit to participate in a dolphin necropsy for two individuals of striped dolphins. These individuals were found washed up on a beach in Struisbaai on the 9th of June and were frozen until plans for the necropsy were decided. It is not certain how long these individuals were stranded until they were found by a cape nature municipal ranger and reported to the local stranding network.
Once both dolphins were placed on the dissection table, they were sprayed with water to remove any excess dirt. A series of photographs were then taken of the individuals from a range of angles, followed by 34 measurements to confirm the species in relation to other cetaceans. Both dolphins were similar in size and on the smaller side, meaning they were juveniles. There was then an external examination to look for any signs of abrasion and to determine the sex of each dolphin, which was found to be one female and one male. After that, external samples of blubber and skin were removed from each dolphin, followed by muscle to be used later on for isotope, fatty acids, and genetics analysis. Chris also took internal samples, including the pieces of the heart and liver, for the whale unit to determine whether each dolphin had healthy organ function. Finally, to examine any auditorial damages in the future through x-raying, both heads were removed and frozen.
Although some might think necropsies are invasive and disrespectful to the animals, such necropsies like this are extremely important for morphometric, biological, and cause-of-death data that cannot be found via any other procedure and are done with the utmost respect.