On August 19th 2013, an ocean sunfish (Mola mola) washed ashore Bar Road, St. Andrews, New Brunswick, Canada.
Tracey Dean, the education director at the Huntsman Marine Science Centre (HMSC), and myself drove down to see the fish in the afternoon. Lou Van Guelpen, the Curator of Fishes at the Atlantic Reference Centre, was on-site taking measurements. He estimated the fish to weigh 350 lbs.
A resident on the street, Henry Clark, offered to use his tractor to move the fish to HMSC. The evening, he placed the fish onto a wooden pallet, and covered it for the night.
That night, the 21 students of the Biology of Marine Mammals course, and the instructors, Dr. Catherine Hood and myself (Amanda Babin) begun preparing for the necropsy, researching the species’ anatomy and separating into teams for efficiency. The teams were as follows:
Head (eye, brain, teeth) – Brittany Barbeau, Katheryn Kastner, Megan Mickle, Jaimie Wylie
Circulatory system (gills, heart) – Emily Guevara
Internal organs (liver, gall bladder, intestines, stomach) – Ashley Tang, Minh Thu Le, Julia Schertzer, Nour Zein
Documenters (photos, videos, sketches) – Melanie Badea, Tom Freeman, Rachel Gould, Alex MacKinnon, Yifu Wang, Sophie Wolvin
The next morning, August 20th 2013, at 8:30am, the fish was moved onto the back of an HMSC truck, and transported to the moose pasture behind the HMSC facilities. With much effort, the fish and pallet were pushed and pulled off the truck into the hole dug into the sand by the students.
Dissecting tools were gathered from the people around the facilities, and the necropsy began at 9:30am.
I began by taking body measurements of the sunfish:
Dorsal fin to anal fin – 238 cm
Clavus to snout – 183 cm
Snout to front of cloaca – 100 cm
Snout to eye – 20 cm
Eye to gill – 19 cm
Total length – 175 cm
Total width – 220 cm
Dorsal fin length – 75 cm
Anal fin length – 74 cm
Pectoral fin length – 27 cm
Clavus length – 37 cm
Clavus width – 85 cm
We then made observations about the external appearance, namely the leathery skin which was beginning to decompose. We took samples of the sea lice living on the skin’s surface. Then we began the internal measurements, with each team doing it’s part.
Skin thickness – 5 cm (It took much longer than anticipated to get into the body cavity)
Eye diameter – 8 cm (preserved one whole eye)
Duct connecting intestine to stomach – 2.5 cm
Cyst(?) found attached to intestines (collected)
Sex determined to be male (testis collected)
Intestines and stomach felt to be full with gelatinous contents.
Samples were collected from the following organs: Skin, dorsal muscle, eye, gill, heart (whole, preserved), intestine, gall bladder, liver, testis, stomach, etc.
The fish was then buried with a fine mesh underneath, and will be dug-up in the future so HMSC may put any remaining pieces of the skeleton up on display.
I want to thank every one of my students who were willing to get their hands dirty with this project. I sincerely appreciate the help in making this necropsy happen!