During our first week as Oceans Research interns, Megan and I headed to the aquarium with second-month intern Claudia, for our first shift. Our morning had an exciting start in which we were able to witness the dissection of a common smooth-hound shark. Ralph, the PhD student who had been practicing the suturing process in preparation for his study now had the opportunity to practice on a real shark that had sadly stranded earlier that year at the Klein Brak river.
Apart from being able to practice suturing on the shark, another reason for the dissection was to learn more about the species. At the time (September 2015) there were no published papers on the reproductive biology of smooth-hounds in this particular area which provided an exciting platform for any discoveries.
The team (Ralph, Enrico (the director of research) and Paul Cowley) were trying to determine why mature female sharks were moving into that particular area and some ideas discussed included whether pupping and/or breeding were incentives for being found there as well as environmental variables such as water temperature and available resources playing a role.
The smooth-hound shark was a large female and Ralph practiced the suturing process that he would be adopting in his study on catsharks, several times. He would make the incision, and practice as if he were getting ready to implant an acoustic tag into a live shark, then stitching the wound up in a secure way, aiming for the entire procedure to take less than 3.5minutes. This is so when it came time to use the technique on live sharks, it would cause as little stress as possible so that they could be safely and quickly released afterwards.
After the suturing practice, Ralph then started the dissection by cutting from the underside above the pectoral fins right through to just before the pelvic fins. During the dissection, we were surprised to see how large the liver was and after enquiring about why that was, Enrico removed a small piece of the liver and put it into a small container of water to demonstrate how buoyant it was. We were also able to see her stomach, intestines and ovaries (which were filled with 22 pups! – 11 in each). We also got to see an in-tact yolk sac that was removed during the ovary dissection.
Following the dissection, we started our aquarium shift by preparing mussels to feed out to the coral fish and collected old mussel shells using a long bbq tong (really handy for reaching the bottom of the tanks!). We also fed flakes to some of the other fish, cleaned inside and outside the aquarium windows, changed the water in one of the tanks using fresh seawater from the ocean (just outside) and also put several whole mussels into the benthic tank for the sea stars.
The pelagic tank also needed a clean so I volunteered to get in with a snorkel mask with the two female smooth-hound sharks and found them very peaceful to watch. It was an amazing contrast being able to observe them swimming around and alert following the earlier dissection of the same species of shark. The water was quite nippy (18◦C) but the whole experience was exciting since it was new to me and I wanted to take as many opportunities as I could while interning so thought why not?!