The first thing I notice when picking up the Short Nose Spurdog Shark is the roughness of its skin.
The shape of their dermal denticles increases the sharks swimming efficiency and allows them to glide silently through the water.
Before we get down and dirty with the dissection, we need to take over 100 different measurements of the shark.
Now all the measuring is done, we take a few photos for our records and get the total mass of the shark.
As the interns start to cut open the shark, they notice just how tough the skin is. A fair amount of pressure has to be applied to make a starting incision. After each dissection we need to replace the scalpel blades as the skin actually blunts the blades.
With the organs exposed we notice just how large the liver is, it is by far the largest organ, weighing in at 32 grams. It’s so large because sharks actually use their liver for buoyancy, as opposed to bony fish who have a swim bladder for this purpose.
After weighing the intestine, we squeeze out the stomach contents just to make the interns squirm, but also to check for any remnants of fish. Our stomach was empty, so we get the mass of it and move onto the reproductive organs.
The ovaries of our shark are developed and containing eggs, so we can deduce that she is mature and was actively mating.
To help with future studies on this species, we next take genetic samples and freeze them for later use. We take 3 samples from the left pectoral fin, as well as a sample of the liver, kidney, muscle and vertebrae.
With the dissection part over, we then enter in all the data and photos to the computer and file away our data sheets so they can be checked over at a later date.
All that is left to do is to throw away the shark bits and pieces and give our tools and table a good cleaning!
All sharks used for dissections are obtained from discarded bycatch from commercial demersal trawlers. This does not create demand and thus increase the exploitation of the oceans.