Society for Experimental Biology meeting, Prague, Czech Republic

That's Prague Castle in the distant left

I have just returned from Prague, where I presented my research on modulation of integration in bluegill sunfish. I have been told that SEB is "the European SICB", and I wanted to go to this meeting because there are lots of researchers in Europe that never make it to the meetings in the US, so I wanted to learn more about what's going on over there.

The first thing I noticed about Europe was from the air - there are lots of farms, but none of them are squares/circles like in the US.  It was interesting arriving in Prague, where the Czech language was so different from most of the ones I am familiar with.  However, some words were still recognizable, like "toalety", which, based on it's location, I assumed meant "toilet".  There were also other things that seemed strange to me, like how the bed covers didn't span the entire bed, and how the shower only had a partial glass door so water got all over the floor. However, some things were still quite familiar, like the american pop music playing in the driver's car on the way to the hotel from the airport. In terms of food, the one thing I noticed was that Czech food = meat, potatoes, and cabbage.  There is little in the way of vegetables, especially the leafy kind. I found myself craving a salad when I got home.

Flight over Czech Republic, nothing is square

Flight over Colorado a week earlier,
everything is square/circle

Yes, that comforter is the only bed covering,
and it's too small

Shower with only a small,
partial glass door

The conference lasted 4 days, and included events like the "Women in Science Dinner" and several keynote lectures.  There was a large Biomechanics presence, and each day had a fair number of talks. I was really proud of my former labmate and current friend Kathleen, who gave a stellar talk on modulation of muscle mechanics in anoles! I also gave my talk, which received some interest on Twitter, mostly because people liked my cool high-speed videos. There were also some interesting talks in other sessions about things I didn't know I would like, including icefish genetics as it relates to anti-freeze proteins.

Kathleen Foster, presenting at SEB

A tweet about my talk

Another great thing about the SEB meeting is that I met so many people from so many different countries, including Australia, France, England, Scotland, Portugal, Lebanon, Canada (including Quebec, which is still Canada), South Africa, Germany, and Poland.  I was joking that I was going to leave Prague with an accent, but I wasn't sure which one. It was really interesting hearing everyone else's perspective on challenges that women (and others!) face in academia, as well as other aspects of academia.

Great group of scientists chatting over dinner

The conference kept me extremely busy, and it wasn't until the third night that I actually made it out of the hotel.  Since breakfast was served at the hotel, and the conference served lunch and several dinners, there was no reason to leave.  It was nice to finally get out and explore the city a bit with Ola, Kathleen, and some students from Cambridge and the RVC. We grabbed some dinner at a place that served local cuisine and then wandered down to the Charles Bridge (after acquiring some ice cream, of course!).

The Prague metro

Imagine that, meat and potatoes

Having some ciders,
that's right, out of a straw

The Atomic Clock

On Friday, Ola, Kathleen, and I decided to skip the morning talks to have some catching up time for the three of us, since we hadn't seen each other in almost a year. We headed back downtown and spent several hours walking around the main part of the city.  I couldn't believe what amazing architecture there was!  It felt like I was in a movie, but I knew this was actually what it looked like here, cobblestone streets and all.  This was also my first chance to try the Trdelnik, a traditional cinnamon/sugar (+ other tasty bits like chocolate upon request!) pastry that is wrapped around and cooked on a wooden spit. I was not disappointed!

The "Tim Burton" castle, as it was dubbed

Gateway to the Charles Bridge,
over the Vltava River

View of the Prague Castle from the Charles Bridge

View of Prague

Cathedral at the Prague Castle

The conference ended on Friday, and the conclusion was dinner at a local restaurant.  A map was provided, but it took 30 minutes and running into a friend I met previously (who was also lost) to finally find it.  It was in the basement of one of the municipal buildings, and there were almost 0 signs for it. The streets are also terrible to navigate, as they seem to belong in Willy Wonka's factory - just when you think you know which direction you're headed, you end up somewhere else.

Conference dinner

It was fortuitous running into Suzanne at the dinner, because we soon learned that both of us had late flights the next day, and coordinated a trip on Saturday to see more of Prague than either of us had time for earlier. I was really glad she let me tag along because she knew of some places to see that I wasn't aware of, including the old castle where some famous composers are buried, and Emauzy which is a 16th century church with original paintings on the walls.  We also stopped at a riverside farmers market and got some strawberries to munch on as well as another local restaurant, this one cafeteria-style.

Cathedral at the Old Castle

Farmer's market

Emauzy

Original painting

One of the hallways in Emauzy

More meat and potatoes

I am so thankful for my NSF funding which allowed me to finally attend this meeting.  I had a great time meeting new people, learning about new science, and exploring a new part of Europe I had never been to.  However, jet lag has not treated me well and now I will spend a few days recovering...

Another trip to Trinidad

Scarlet Ibis returning from Venezuela

I have just returned from Trinidad (the country, not the city in Colorado) with Cameron Ghalambor, Craig Marshall (a new PhD student), and Travis Klee (a new Bachelor of Science). Unfortunately, we didn't have internet so I couldn't post about the trip as it happened, so instead, I will have try my best to recall the details and events.

Cameron and Craig arrived in Trinidad on June 10, after almost missing their flight from Denver, being delayed in Houston for about 4 hours, and arriving in Trinidad after the rental car place had closed. The next day, the plan was for them to obtain permits, scope out field sites, and purchase some groceries before Travis and I arrived in the evening. They were mostly successful except in regards to the permits (they arrived at the permit office at 3:40 only to be told they closed at 4 and were currently closed, welcome to "Trini time"). At least they managed to track down a rental car by the time Travis and I arrived at 10:30. We also had delays in Houston because the pilot couldn't get one of the engines to start (kind of a big deal!), but we did manage to get upgraded to the front bulkhead row and got free TV. Other than the delay, we made it to the field station with relatively little trouble.

The Reznick guppy facility near Arima, Trinidad

The plan for collections was to get three guppy species from a range of salinities for Cameron and Craig (Poecilia vivipara brackish, P. picta brackish, P. picta fresh, P. reticulata fresh) and 2 high predation/low predation pairs of P. reticulata for me. We started by collecting the brackish fish at a boat dock in the Caroni Swamp on the western side of the island.  We were very successful at collecting fish, but the vivipara turned out to be more difficult to catch with our butterfly nets than we anticipated.  We also tried seining but our net was small and we didn't catch any guppies (though we did catch other things, like eel/leptocephalus larvae). We also managed to find a site close to the boat ramp that was freshwater and were able to sample the freshwater picta. They were densely concentrated under the vegetation along the shore, which made sampling go very quickly. This is ideal since we don't like keeping the guppies in the transport bottles longer than necessary.

The boat canal in the Caroni Swamp

Cameron (left) and Craig (right) catching guppies

Cameron sorting guppies into bottles to be
transported back to the lab

The swamp is about an hour drive from the lab, so unfortunately we had some mortality when we got back.  But being scientists, we took this as a learning opportunity to try to verify the species we caught and distinguish vivipara and picta females.  Because guppies are small, sometimes it is easier to tell these differences on a fish that isn't swimming around.

Craig and Cameron sorting guppies

Examples of some of the fish from the Caroni swamp.
Male picta were obvious and are grouped on the right.
The middle column is most likely picta females, with the
exception of the first two, which are viviparafemale and male.

The next day we headed to the north slope of the mountain range to collect some freshwater reticulata from HP and LP sites.  We stopped quickly at one of the beaches along the Caribbean Sea then headed to our sites on the Yarra River. We sampled the HP site first, and saw lots of other cool fauna, including a large cichlid guarding its young, shrimp, and schools of characins (look like large tetras). Then we headed back up the Blanchisseuse Road (not for those with sensitive stomachs) to the Yarra LP site, which took some exploring to find the dirt road leading down to the river.  When we got there, we were greeted by a group of about 5 guys with a dead goat tied to a tree that was in the process of being butchered.  I couldn't make this up if I tried. They were very cordial though and had no problem with us collecting guppies upstream from them.  They did try to help by telling Cameron about some "big fish" near where they were working, and when Cameron asked if there was blood in the water, the response was "I just killed a goat". We did not sample there.

Las Cuevas Beach

Sampling the Yarra HP site

Sampling the Yarra LP site

We were very fortunate in that the rain held out most of the time we were sampling, so the next day we headed to the Aripo River on the south slope, which drains into the Caroni Swamp eventually.  We sampled a LP site that is also referred to as the Naranjo River.  Though this site has traditionally been sampled extensively, we found a healthy population. However, we did make sure to only remove a small number of individuals from each pool. We found a lot of killifish (Rivulus/Anablepsoides hartii) at this site as well, which only prey on juvenile guppies and are considered a minor predator. On the way home, we also stopped by the site of the Endler LP introduction about 40 years ago.  Again we found a healthy population that could potentially be a site for future studies.

The Naranjo/Aripo River LP site

Looking upstream

Killifish, Rivulus/Anablepsoides hartii back at the lab

After taking the fish back to the lab, we headed back out to the Caroni River again, this time further upstream so I could catch some freshwater reticulata from an HP site to pair with the Aripo LP site. We checked a site that I had sampled the last time we were in Trinidad.  However, that time was in the wet season and the river was difficult to sample so we were left with sampling one of the drainage ditches nearby.  These fish ended up being very unhealthy so not many survived when we returned to Colorado.  This time, however, we were able to sample the river.  The population wasn't as high density as the one near the swamp that we sampled a few days previously, so it ended up being the site that took the longest amount of time to finish, but it was still only about an hour. We had to be quick because just upstream someone was cutting down bamboo stands and were getting closer and closer to us and we didn't want them to fall on us.

Cameron looking for guppies in the Caroni River

Cameron and Craig also needed some freshwater reticulata since their previous freshwater site ended up being about 90% picta, so we went searching for a nearby site they could use.  We ended up near a road crossing in a popular spot for "liming" (aka, partying). Once we located a good vegetation patch with lots of adults hiding in it, it only took a few tries to get all the guppies we needed.  However, in the meantime, Cameron managed to find a fire ant colony that apparently he was sitting on.  He was a trooper because he brushed them off and continued sampling guppies. At this point, we had now collected everything we were targeting, which is pretty good for only 3 days!

Sorting guppies on the Caroni River (post fire ant attack)

Travis and some guppies caught at the Caroni HP sites

After a hard day of exploring, collecting, and fire ant attacks, we decided not to cook dinner, but to instead go out for some Trini street food called doubles.  They're sort of like a taco, with two pieces of bread overlapped on the bottom, then doused with a chickpea sauce and potentially other sauces.  If you're brave, you can ask for "plenty peppa".  I was not brave but the guys were. Each doubles stand is unique and we found some that serve them with other ingredients like ground chicken or a mango sauce.

Eating doubles

Looks like what you might
see in a baby diaper

Cameron had to head back to Colorado the next morning but the rest of us stayed another 2 days.  We used this time to try to catch some pike cichlids (Crenicichla frenata).  These fish are piscivorous and are one of the main predators of guppies in the HP sites.  We needed to catch a few to bring back to Colorado so we can use them for a "predator" treatment in the flow-through systems. We were told the best way to catch these is using hook and line with guppies as bait, so we headed to a few HP stream sites to see what we could do.

The morning started with a downpour and was the official start of the rainy season. We weren't able to get out for the first few hours, but once it cleared up we headed out to the El Cedro River.  We got (vague) directions to the site from a few people, with the warning "DO NOT go to the dump".  Apparently this is where very desperate people live and will attack people looking for anything they think will be valuable to them.  We thought we were going the right way, then saw a man in an orange vest that looked like he was checking in cars at a gate.  Immediately I realized it was the dump, so we had to turn around quickly and head back.  We eventually found the river in what looked like someone's driveway, but after poking around for about 20 minutes, we didn't see much of anything, including guppies.

The El Cedro River

Next, we headed to an Aripo HP site to try again for pikes.  We had to do a little more exploring to find the trail leading down to the river, but eventually found it.  It was kind of fun to actually do more of a hike to get to a site, rather than just pulling over on the side of the road.  This was the first site where I expected to see a fer-de-lance or bushmaster, the two venomous snakes found on the island, but we didn't see any. I guess that's actually a good thing. The river was beautiful when we got to it, and we had a clear view of the waterfall separating the HP and LP sites (predators have a difficult time scaling these, but somehow guppies and killifish can do it). Not long after we arrived at the site, we were overtaken by some kind of flying insect.  They didn't bite, but it was annoying because it made it difficult to concentrate on trying to fish.  I even had one fly into my eye.  When we got back to the house that evening, we learned that the rain earlier in the morning caused the termites to emerge.  We did see a lot of other fish at the site, mostly the larger Characins, but were unsuccessful at catching a pike.

Aripo River and waterfall

The rains brought out a lot of amphibians, and we decided that evening to go on a herp walk to see what we could find.  We probably saw at least 5 species, including ones that were inflated floating in a puddle.  We also saw some cane toads and some other frogs that we weren't sure exactly what they were.

The next (and last) day we tried for pikes again in the Oropuche River.  In contrast to all the other sites we had been to, this river drains to the Niriva Swamp in the east. We tried for a while and were unsuccessful at catching anything using our guppy bait.  This site is also a popular liming spot, so one of the locals came over to help us.  He suggested using some crackers (which he donated to us) to draw the small fish in, and the big fish will follow.  While this seemed like a great suggestion, the river was flowing a little too fast for this to work well.  However, Travis managed to figure out a way to bait the smaller characins and scoop them up with one of the butterfly nets.  Then we were able to use these for bait, which were much bigger than the guppies. After about 2 hours of trying, we had several bites, but were unsuccessful at catching anything. Then we met another local who actually collects fish and works for the zoo in Port of Spain.  He told us they catch them using a seine that spans the width of the river. We didn't have one that big, but we did try walking upstream a bit to find one of the spots he suggested.  We never did catch any pikes.  Fortunately, one of the other researchers went out to El Cedro for killifish that night and was able to net one for us while it was sleeping, so we were able to bring one back in the end.

Travis and Craig fishing for Pike

Me fishing for pike

Marianne, the pike cichlid

We wanted to make sure we did one thing for fun while we were in Trinidad, so the last evening we took a boat tour of the Caroni Swamp to watch the scarlet ibis return to their roost after foraging in Venezuela for the day. We saw lots of other wildlife too!  I'm really glad we had a chance to get out in the swamp a bit.

Me, Travis, and Craig

Four-eyed fish, Anableps

Tree boa

Silky anteater

Scarlet ibis

So in all, I would say it was a very productive trip.  Only about 5% of our fish died on the flight back to Colorado, and all are looking healthy and happy in the lab. Now I have no excuses, time to collect some data!

Finally! An evasive prey for guppies!

Finding a challenging prey type for the guppies has posed quite a challenge for me!  I have spent the past few months trying to work out the kinks in my data collection, and a big one was finding a prey that guppies like, that is relatively evasive, but that I can also successfully culture in the lab.  To determine differences in feeding between populations of guppies, the prey need to be challenging to capture so that each fish has to work to catch them.  Alternatively, I also want to film them with a prey type that requires a completely different type of capture, so will also be using frozen flake paste spread onto a die that they have to scrape to remove.  But this second prey type was easier to figure out.

Early trial of a guppy capturing brine shrimp nauplii (way too easy!)

In terms of an evasive prey, I have used other, smaller fish as prey in the past, but this doesn't work with guppies since they're not piscivorous.  At SICB I was listening intently to Jeannette Yen's talk on copepod evasive behaviors, and was convinced this is what I needed.  However, at this time all the lakes in N. CO were still frozen, so it was not really possible to check out the local stocks.  So I tried my hand at both freshwater (ordered online) and saltwater (bought locally) copepods, but couldn't get those cultures to last more than a week for some reason.  I needed to try something else.

By this time the lakes had thawed, so my next tactic, because why not, was to gather my undergraduate helper Travis, some plankton sieves, and my kayaks and spend the day at Riverbend Ponds Natural Area to see what we could catch.  Fortunately, we did come back with some plankton (though the water was FREEZING!), and upon inspection under the microscope, saw that indeed it was mostly copepods!  It also had lots of rotifers and daphnia but we tried to sieve out what we could to keep the copepods.  So we put them in our culture bucket, fed them some phytoplankton paste, and let them "soak" for about a week.

Riverbend Ponds Natural Area, Long's peak in the distance

To our surprise, what was a culture of copepods a week earlier was now a culture of Daphnia!  Since it seems to be the only zooplankton I can keep alive, we decided to go with it.  The Daphnia are also larger than the copepods, so they show up on the camera more easily (a plus!).  However, I was worried that they would be too easy for the guppies to catch.  So I gave Travis the task of filming some guppies to see what would happen.

Travis doing some filming
(note the foil to keep the camera from melting!)

To our surprise, the guppies loved to eat them, and appeared calm and willing to eat for us, which was a first!  Even more of a surprise was that, when we examined the video, it looks like Daphnia can evade guppies from a good distance, and so are a relatively evasive prey.  Here's a video (Daphnia at the bottom left):

... and a close-up of the predator-prey interaction:

I'm also working on digitizing a few trials to get some preliminary data.  Here are the locomotor data for the trial in the videos above:

Prey velocity, prey acceleration, predator velocity, and predator acceleration

It's pretty clear from this figure that the Daphnia actually does 3 escape responses, and that the guppy steadily approaches its prey and rapidly decelerates during capture.  I only digitized the first capture attempt so the successful one isn't shown on the graphs above.

Long story short: Daphnia single-handedly rescue my post-doc!

Nature vs. Nurture - 7th graders visit CSU

Today I hosted 22 7th graders from Mapleton Expeditionary School of the Arts (MESA) in Thornton, CO (over an hour from here).  Their teacher, Ashley Luythe, asked those of us in the biology department if we could help her teach a unit on heredity and genetics.  I thought the guppy work was perfect since much of our work uses common-garden style experiments to test whether phenotypes are driven by genetic or environmental influences.  So I helped them arrange a trip up to CSU to learn about what we do.

We started the day by talking about genotypes and phenotypes, environmental and genetic influences (with an example using handedness), and why we use guppies to address our questions.  Then we had a lot of fun modeling the effects of color on predation risk using skittles as our prey.  We put them on colored backgroundsto see how many of which colors were "captured".  Once the students generated histograms of their data, we found out that the skittles that matched the background were "captured" less often!

Preparing to "capture" skittles

Making histograms

Discussing the role of color in survival

We also looked at 4 guppies and compared their color.  Two guppies were low predation brothers that were raised in two environments, and the other two were high predation brothers raised in two environments.  By knowing the genetic background as well as the rearing history, we determined that color brightness in guppies was primarily determined by environmental changes!  The students also had a chance to tour our guppy rearing facility at the end of their visit.

Examining guppy coloration

Comparing guppies raised in different environments

Discussing genetic and environmental influences

After talking about guppies, they also heard from Molly Womack, who talked about her research on earless toads!  She brought cleared and stained toads, a fish embedded for histological sectioning, and live eared and earless toads for everyone to see!  She also gave the students a chance to ask those burning questions about her life as a graduate student.  They had great questions!

Examining two species of toads

This looks like a fishing story..."it was THIS big!"

A cleared and stained toad

Thanks to several graduate and undergraduate students for helping with this activity: Rachel Bockrath, Dale Broder, Francis Commercon, Travis Klee, Mitchell Leroy, and Molly Womack!  Hopefully their trip to CSU inspired the 7th graders to learn more about genetics and heredity.

ICB manuscript accepted!

Look for my manuscript in Integrative and Comparative Biology soon (Update 5/15/15: it's out now here http://bit.ly/1L6KIzE)!  This is a compliment to what I presented at SICB in West Palm Beach at the symposium "New Insights into Suction Feeding Biomechanics and Evolution" organized by my PhD advisor, Tim Higham, and his PhD advisor, Peter Wainwright.

What are our predictions of how an "integration space"
explains fish diversity?  Read the paper to find out!

In summary, we were interested in increasing awareness and providing methods and a context for thinking about complex behaviors and how multiple functional systems can be coordinated and integrated when they work together to accomplish a common task.  We use prey capture in fishes as the common task involving both locomotor and feeding functional systems as an example of this idea because of the extensive background on each system in this group.  We aim to do 4 things in this paper: 1) discuss complexity and integration and what they mean to biomechanics, 2) discuss the importance of integration for understanding patterns of diversity (here we hypothesize the integration space above), 3) provide empirical demonstrations of integration using a meta-analysis of ram and gape from several species found in the literature as well as a multivariate re-analysis of previously published sculpin data, and 4) discuss how this approach adds novel insights into organism function and diversity as well as outline future questions related to these ideas. We hope this work can be used to drive the future of study on complex functional behaviors, and that future work on fish feeding acknowledges the potentially significant role that other systems, such as locomotion, can play in diversification patterns.

For fun, here are some videos of black crappie (Pomoxis nigromaculatus) capturing two prey types.  Notice the very interesting locomotor strategy of crappie when capturing evasive fish prey - a roll behavior, coupled with a slow stalk and quick burst of acceleration.

This is not observed when capturing other types of prey such as frozen bloodworms.

Interesting examples of the importance of locomotion during prey capture!