On the afternoon of December 5th, while Nicole and Brooke were responding to a dolphin in N Myrtle Beach, we got a call from USCB dolphin researchers about a deceased dolphin down in Port Royal. Our colleagues, Bonnie Ertel and Colin Perkins-Taylor, were able to help us out and retrieve this animal.
After a long afternoon of conducting a necropsy on the Myrtle Beach dolphin, Bonnie and Colin arrived at the lab in the evening with the second animal. We conducted a preliminary examination and stored the dolphin on ice overnight.
This was a 6.5 foot male bottlenose dolphin.
The following day, Lauren, Nicole, and LMMN volunteer Nora Futrell conducted a full necropsy on this animal. Nothing appeared particularly unusual until we examined the trachea. Upon opening the trachea, we found something that should not be there - a fully intact fish.
Dolphins have evolved to have separate pathways for air and food. While we, as humans, have an epiglottis - a cartilaginous flap - that helps keep food and liquid from entering their windpipe/lungs, dolphins have a unique modification that separates the trachea (pathway for air) from the esophagus (pathway for food). They have an epiglottic spout, or “goosebeak” - a cartilaginous structure supported by muscles and connective tissue - which keeps the respiratory and digestive tracts separate when a dolphin swallows food.
The goose beak is designed to keep anything but air out of the lungs.
The entire goosebeak on this animal was removed and examined and we found that it was deformed and necrotic. It is not immediately clear whether the deformed goosebeak was present since birth or if it developed as the result of a virus or disease. It is likely that this animal was still able to breathe and eat for some time, however, it only took this one fish to accidentally get lodged in the trachea and likely caused immediate asphyxiation.
This dolphin's' stomach was very full with partially digested shrimp and fish, indicating it was likely in the middle of feeding when it passed. This was a sad situation and an unfortunate passing for this animal, but, it was a very interesting case for our team.
Thank you to Alyssa Marian with USCB for reporting this animal, to Bonnie and Colin for retrieving the animal, and to Lauren, Nicole, and Nora for conducting the necropsy.