Hunting Peanut Worms in the Caribbean

Last month some of the Collin Lab members set out to the field at first light.  They were headed all the way across the country (a full hour’s drive!) to Galeta Marine Laboratory on the Caribbean coast of Panama.  This lab hosts research but is primarily used for outreach and education for kids in the city of Colon.  

Panamanian students learning about their 

environment from STRI Nature Guides.

With seagrass lagoons, mangroves and coral 

reef patches, Galeta is one of the most 

well-studied Caribbean sites in Panama.

The goal of the trip was to hunt for peanut worms.  They are the center of a biological controversy.  Are they regular segmented annelid worms that have lost their segments.  Or is the un-segmented body with a strange inverting proboscis unique and evolved independent of other worms?  We join Tupper Postdoctoral fellow Michael Boyle in a search of these peanut worms.

Intern Allan Carrillo searches for substrate

The worms are often found inside rock crevices and coral rubble or mud flats.  That’s why, we needed to collect rocks and coral rubble from shallow water (0.3-2 m).

We didn’t just see worms.  If course, we saw slugs and snails too.   The reef-flat is full of interesting invertebrates and seaweeds. 

But, most important, we found them!!! A bunch of specimens of Phascolosoma perlucens and Aspidosiphon sp. that with luck, will spawn.   If they do, Michael might use them as a model for his studies of evolution of development.

Michael carefully cracks open dead
coral heads to look for the worms.

And....after all that hard work... here he is!  

Phascolosoma perlucens!

Post prepared by:  Allan Carrillo

Congratulations Kecia!

Today is a big day for the CollinLab. 

Kecia Kerr, the first PhD student from the CollinLab successfully defended her dissertation.  After 5 years of hard work and intensive questioning on her research, Kecia will be awarded a PhD from the NEO Program at McGill University.   It’s a great accomplishment and her project has produced some cool results.

Working with fiddler crabs, Kecia focused on how changes in temperature influence the timing of reproduction.  These crabs are good mothers and after brooding their eggs, they time hatching to occur when predation risk is lowest for the hatching larvae.  In most places around the world female crabs release their tiny larvae at night on the days with the biggest tides. We think this is because predatory fish can’t see the larvae very well at night.  And, that during large tides the water sucks the larvae offshore to safer areas; away from predators that are more common in the shallow water.

Climate change is expected to alter the seasonal upwelling of cold water that normally happens between January and May here in Panama.  It is likely that the intensity and also the frequency of these events will increase.  Kecia wanted to know if the crabs will be able to adjust to the more variable temperatures we expect to have in the future.

Changes in temperature can alter the rate of development.  So how can the crabs ensure that their larvae hatch at the right time?  Kecia found that different species do different things.  One species can predict the temperatures that they will experience while they brood.  They use their experience of current temperatures to adjust when they mate and lay their eggs.  Females of the other species are not flexible in when they mate or lay eggs.  Instead these crabs can adjust the temperature experienced by their eggs:  The females move up and down in their burrows finding the right temperatures to keep their eggs on track to hatch on time.

Even with these strategies the crabs sometimes make errors and release their larvae on the wrong days.  How these errors effect the survival of the crabs is a question Kecia hopes to answer in the future.

Kecia’s first dissertation chapter is already published.  You can read it in Marine Ecology Progress Series here:  http://www.int-res.com/articles/feature/m459p001.pdf

Watch these videos to get an idea of what Kecia’s fieldwork is like.

http://www.youtube.com/watch?v=H0sCjgZ5y9A&feature=plcp

http://www.youtube.com/watch?v=hIsy0ZoyxCU&feature=plcp

Failed papaya crop

Almost everywhere you go in Panama you see papaya trees, laden with fruit growing, around the houses.  There are trees dripping with fruit in the parking lot at work.  We pass them walking the narrow trails to reach the beaches where we work.  We see them squeezed in between houses in the city.

I’ve been trying to grow some of my own.  And I’ve discovered that birds feed on them.  Not on the fruit but on the trees themselves.  It seems that for the second year in a row I won’t have much of a harvest, but I’ve seen some interesting birds and their behavior. 

Few birds commonly consume leaves.  But these grey-headed chachalacas are generally herbivorous and seem to enjoy papaya leaves.

Another day I got a clear view of why there are so many flowers but so few fruit. This collared aracari is tossing back the flowers (literally)