Fishies!

Ah, fish.  Vertebrate swimmers inhabiting all water types and conditions.  They're fascinating creatures, that's for sure.  I'm pretty glad I feel this way, considering I'll be spending a lot of quality time with dead fish for the next week.  For our parasitology class, we once again have independent projects, but on a much smaller time scale than the last course.  I'll be studying ectoparasite diversity and abundance on the gills of fish, comparing both native and invasive freshwater species.  According to the literature, we expect to find fewer parasites on the invasive species, as their associated parasites often don't survive the move.  Hopefully, that's what we'll see.

Anyways, we've all had fish on the mind for the last 2 days.  Yesterday, we dissected the invasive freshwater Peacock Bass.  Our TA's picked up some leftover carcasses from the fishing docks on Lake Chagres so we could examine the parasitic content of the gills.

Fun fact about the Peacock Bass.  It was introduced to the area because an exotic aquarium fish dealer was raising the bass in a tank in the lake.  This was all fine and good - fish couldn't escape - until a huge rainstorm flooded the lake, and water levels rose.  The Peacock Bass floated out of their tank and presto! An invasion began.  Peacock Bass are doing incredibly well, which poses a problem for the native species that can't compete as aggressively.  Fortunately, the bass are a great game fish, and good eating, so both tourists and commercial fisherman alike assist in culling the population.

Peacock Bass

Dissecting is fun!

Bass gills, ready to have the filaments cut off and examined under the microscope

Today, after visiting the Gorgas Institute for Tropical Diseases, where we learned about Chagas disease, the class made a stop at El Mercado de Mariscos, in Casco Viejo.  The market was pretty amazing.  There were a bunch of vendors with anything ranging from shrimp to lobster to octopus to massive, unidentified pelagic fish.  Can't say the smell was all that wonderful, but it was truly a sight.  While the TAs went to find some marine fish specimens for our dissection later in the day, the rest of us wandered around and took it all in.

I was amazed by the prices of the fish.  This was literally the freshest of the fresh fish, brought in today off boats from the harbor right next to the market.

Shrimp!

Cleaning a fish for a customer

Fishing boats in the harbor next to the market

A cute little boat with Casco Viejo in the background

Part of the outdoor ceviche restaurant line-up

Me and Nikki out by the harbor

Nothing like fresh Ceviche (photo credit Kristie)

After buying our obligatory ceviche, we got back on the bus and headed back to the schoolhouse for some marine fish dissection.  We looked through all the organs today - gills, stomach, intestines, liver, heart, and gonads.  I couldn't help but think it seemed a bit odd, and just slightly unnerving, after eating ceviche from that market, to be investigating parasites on the fish we'd been eating.  Fortunately, for our own peace of mind, no groups found parasites in their specimens.  It's nice to know, retrospectively.  According to Sebastian, our fish expert and TA, today was an anomaly.  Keep that in mind the next time you bite into that piece of sushi...

Tomorrow, Nikki, Blair, Patricia, and I are rising at the crack of dawn for some field work, AKA fishing.  Hopefully we'll catch enough Peacock Bass and some native species to start our independent work.   All I know is that I'm looking forward to six hours on a boat; fishing, relaxing, and soaking up some sun.  Field work is really tough...