From February 15 to the 24th
the freshwater people in my lab (Caleb McMahan, Dr.Wilfredo Matamoros)
and I went on a trip to collect fishes in Costa Rica. Marine postdoctoral
fellow, Dr.Matt Davis, was left back in Baton Rouge to hold down the
fort. (Don’t worry he will go to Panama with the rest of the lab in March and
April, while I stay behind with my very pregnant wife.) Caleb, Will and I were
after cichlids, poeciliids (livebearers) and other freshwater species that are
related to my NSF funded project in Central America.
This was my first freshwater collecting trip to Central
America in six years and I learned quickly that my team was much better at this
than I was and even better than I thought I was. Caleb has been collecting
heavily from freshwaters in Mexico, the U.S. and Jamaica for his masters and
undergraduate projects and Wilfredo (without exaggeration) is one of the most
well respected collectors of Central American fishes alive today. Wilfredo has
many years of experience collecting in remote parts of Central America, which
is why I brought him aboard as a postdoctoral fellow this past fall. Also with
us were two superior Costa Rican collectors, Arturo Anguilo Sibaja and Carlos
Garita Alvarado. These two master’s students from the Universidad de Costa Rica
were tremendous collectors and they knew many remote sites where we could
collect. They were also very intelligent young gentleman who we made fun of constantly
(they did the same to us with less success). In the eight days that we were
sampling fishes we put nearly 1000 miles on our rented vehicle in a country
that has a coastline of 1100 miles. We collected in every major drainage, in 26
localities, and in six out of the seven provinces as we circumnavigated the
entire country.
We collected about 90% of our targeted species. Our final
tally was nearly 4000 specimens from over 150 species. It was one of the most
successful collecting trips I’ve ever been on, which was a surprise given how
we started. After a couple of days of getting settled in San Jose getting our
rental car and gear together, we started our drive to the southern Pacific
slope in the province of Puntarenas. We arrived just as the sun was setting and
found ourselves a nice little beach hotel (one of many Hotel Iguanas that we
encountered) with Golfo Dulce and the Pacific just to our west and with Panama
to the east. We decided we would sample that night right in the back of the
hotel, which was conveniently located on the beach. Although we were primarily
after freshwater fishes, marine fish were also on our mind particularly mullets
(Mugilidae) a taxon Caleb has an unusual, and perverse, fondness for. After
about an hour at the beach we had collected a marine catfish, a spadefish
(Ephippidae) a rare threadfin (Polynemidae) and several other species. It was
already 9pm and I was toast, but the site of fish made the blood lust come out
of Caleb and Will and they decided that we needed to hit a freshwater site, the
Rio Coto, that night. The entire time the strange hotel manager was following
us around and he even helped (sort of) pull seines on the beach. As we headed
off to the Rio Coto he grabbed a couple of beers and hopped into the back of
our SUV.
As I started recording GPS coordinates and writing field
notes the UCR students started pulling a seine in the shallows near shore,
almost immediately Arturo cried out in pain. He climbed out of the water with a
nasty gash across his foot, he said he was pinched by a crab but it looked much
worse than anything a crab could impart. He went to lie down and to elevate his
foot while we stoically carried on with the fishing, we ended up getting an
additional 10 species at that site after about half-an-hour. We called it quits
around 10pm with the intention of returning the next morning. Back at the hotel
the arduous work of sorting, photographing, IDing, tissue-ing, and labeling
began. One of the unfortunate things about collecting is the necessity of
processing these materials while fresh. The hotel manager, now completely
drunk, did not make things go faster with his bad jokes and shenanigans but any
hotel owner who didn’t mind us laying out 100 or so muddy fish across his
bathroom floor surrounded by razor blades and alcohol vials is an okay guy in
my book. Not to mention the olfactory nightmare that the mix of formalin, ETOH,
fish, sweat, beer, and Arturo’s bleeding foot produced. I’m not sure when we
got done that night, but as it was with the rest of the trip, we were off early
the next morning before we could get too relaxed.
We didn’t actually catch a cichlid until our eighth field
site on the third day of collecting, a fact that had me very worried since we
were there primarily to collect members of this family. Cichlids are very
species rich in Central America, with over 100 species, and this family has
been there for a long time (more than 50 million years in some parts if you
believe my publications). Because they are obligate freshwater fish, cichlids
can tell us about the history of the geological blocks that make up Central
America. Central America is a landbridge that connects North and South America
that has only been in its present arrangement of four interconnected geological
blocks for the past three million years. The geological blocks are older but
their arrangement and the movement of those blocks over the course of the last
60 million years is hotly debated among geologists. The history and
phylogenetic relationships of cichlids and other freshwater fishes on these
landmasses can tell us a great deal about which geological hypotheses make the
most sense. The biological data provide an independent line of evidence for
supporting or rejecting the geological theories. Our plan was to collect as
many cichlids and other freshwater species as possible. Although we didn’t
collect any cichlids at first they started coming in bunches after day three.
We ended up with 20 of the 22 species of cichlids we were targeting. It was
amazing to see how each river drainage had its own assemblage of endemics.
Cichlids are gorgeous fish, almost all have brightly colored bodies and fins
and many have blue or lightly colored eyes. (This coloration is why they are
among the most popular aquarium fish.) Even though we were not traveling
tremendous distances between sites we could see huge differences between upland
and lowland sites and between Pacific and Caribbean coasts. Costa Rica is one
of the most developed countries in Central America so it was great to see that
the diversity of forms were still there. In fact, we know of at least two new
species that we are planning on describing. In July Arturo and Carlos will be
coming to LSU to help us describe those species and to determine if we have even
more new taxa.
Besides the upcoming Panama trip my lab will also
be traveling to Nicaragua, Guatemala, El Salvador, Mexico and Honduras over the
next few months. Stay tuned....