Fish Days (Thurs - Fri July 9-10)

We had lectures on Thursday on everything fish - anatomy, physiology, major bacterial, fungal, and viral diseases, and parasites. It was a long, long day, and I was looking forward to getting out in water on Friday to actually see some of the fish--and maybe even their parasites--that we talked about.

Friday morning we headed out in boats to one of the spoil islands in the intracoastal waterway just across from the HBOI channel. The spoil islands were created when they dredged the channel in the intracoastal for boats, and piled all the solid stuff up to make little islands. Some of the guys helped drag in a huge seine net from the boat, and we collected a whole bunch of fish and other little creatures from the water just off the island.

Field site set up on the spoil island

Some of the things we saw included
--a lot of stingrays (which made me feel better about the "stingray shuffle" walk that we've all been doing in the water since we got here to avoid stepping on them and getting stung)
--lots of various size snook
--Lookdown fish
--a bigger barracuda than the teeny one we caught the other day
--mullet fish
--a whole lot of small baitfish that we threw back

The HBOI staff had set up a whole little field station on the island so that we could do PEs, skin scrapes, blood draws, and anesthesia/euthanasia on the fish that we caught. This was great, except for the about 100,000 mutant mosquitos that were swarming around me at all times, and obviously had missed the memo that they were supposed to fear the copious DEET I had sprayed on. At one point I retreated back into the water up to my shorts so that they couldn't get at my legs anymore.

But mosquitos aside, the morning was really interesting. I started out doing PEs on the two snook that we kept. We were planning to re-release the snook, so we didn't anesthetize them, and had to be very careful handling them and making sure that we were aerating the gills when they were out of the water buckets. I failed miserably in my attempt at bleeding the snook, but I did manage to keep it alive and happy enough to let it go at the end. The stingray and mullet that I did manage to bleed--through the heart, instead of the ventral tail vein--weren't so lucky, but we euthanized them and were able to bring them back to the lab to necropsy in the afternoon.

I'm getting a blood sample from the stingray!

The necropsy lab following our field collection was great, we necropsied all of the fish that we caught and decided to euthanize. I worked with Joanna on a mullet that unfortunately for us didn't have any interesting parasites. A few people did find parasites, so we looked at some of those under the microscope, as well as normal skin scrapes, gill biopsies, and cloacal washes. I had a nice feeling of actually having learned something during first year when I was able to recognize the visceral organs of the fish, and remember some of the specifics of elasmobranchs like the spiral colon and salt gland. I was definitely having flashbacks to Comparative Anatomy labs with Dr. Hermanson, and I think those will continue all week as we move to dissecting amphibians, reptiles, and marine birds.

Later in the day we took a tour of HBOI's aquaculture facilities. They're working with the USDA on researching new ways to culture different species, and also lease space to ORA to culture aquarium fish. The aquaculture demand for clownfish has apparently skyrocketed since Finding Nemo, and we saw lots and lots of Nemos. A female clownfish typically broods her eggs in an anemone, and if she dies one of the offspring will become female and take her place....I can imagine that Pixar didn't want to deal with the complexities of that situation!

Aquaculture of "expensive food fish"

So many Nemos!