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The Guppy Project



Videos from Trinidad


Video Menu

*I. Seminars & Presentations

  1. "Experimental Studies of the Interaction Between Ecology and Evolution in a Natural Ecosysten -- 6 year Progress Report":  Seminar by David Reznick, presented as part of the Ecology and Evolution Seminar Series at UC Davis on Feb. 14, 2013.

 II. Introduction to the Guppy Project

This is an illustrated, multi-part introduction to the academic background of our project.  I explain what the main goals of the project are and why they are of interest. 

  1. Preamble - Introduction to FIBR/ Part 1 - A traditional view of the relationship between ecology and evolution:  The majority view today is that ecology shapes evolution.
  2. An alternative view – evolution and ecology interact with one another:  A minority view, supported primarily by a small body of theory and laboratory studies, is that ecology and evolution are intertwined with one another, so that evolution shapes ecology at the same time that ecology shapes evolution.
  3. Guppies- Part A & Guppies - Part B: Here I introduce our study organism, which is natural populations of guppies from the island of Trinidad. I explain why natural populations of guppies are good subjects for asking whether ecology and evolution interact in a natural ecosystem.
  4. Our project; Part A & Part B: I then explain how our partnership of evolutionary/population biologist, ecosystems ecologists, theoreticians and evolutionary geneticists are teaming up to evaluate the interaction between ecology and evolution in nature.

All of the following videos were taken between September 16 and September 26, 2009.  This is a time when there is often a lull in the rainy season, which extends from May through January.

III. River Tour:

I will take you on a tour of the river where we are doing our work, beginning downstream, where the river is large and flows through a deforested landscape, then proceeding upstream to our study sites.  As we go upstream we enter a forested landscape, then move into the smaller tributaries where our work is done.  At each step along the way, I will explain how the fish community changes plus offer some insights into what the ecosystem is like.
  1. Introduction to the fish: You will see examples of the fish found in the river plus learn about how the fish communities change as you go from downstream to upstream.  The downstream area has the greatest number of fish species.  Species are eliminated as you move upstream until we reach sites with only a single fish species.
  2. Lower river, near the Eastern Main Road:  Here the river flows through a deforested landscape, but also has the most diverse fish community.
  3. Lower river, a bit further upstream:  We are at the border between a deforested landscape and the beginning of the forest.
  4. Lower river, at the gateway to the forest:  We look upstream, just above #3, at a river that now flows through an intact forest canopy.
  5. Quartz boulder and the narrows: You will see a large quartz boulder, wedged into a narrows in the stream formed by a solid rock ravine and look downstream into the rocky narrows.  This stretch of stream is the barrier to the upstream dispersal of many species of fish and forms the border between a more diverse community downstream and a less diverse community upstream.
  6. Quartz boulder, facing upstream:  The river is now smaller, rockier and more heavily shaded by a forest canopy.
  7. Upstream from the quartz boulder, after a rain:   A view of the river above the boulder when the water level is higher because of an afternoon downpour.
  8. Upstream from the boulder the next day: The sun has come out and the water level has fallen.
  9. Transition from the main river to a small tributary. You will see a tributary that flows through a series of cataracts then a narrow rock chute before entering the main stream. These formations are the barrier to all but one species of fish.
  10. The tributary further upstream – light, forest, cocoa and coffee:  You will see one of our study sites, which are small, headwater streams.  I explain that, while this may look like virgin forest, it is actually second  growth forest  filled with abandoned cocoa and coffee trees.
  11. Geology/topology of the study sites: Our streams flow through steep ravines that have no trails, so the rivers are our roads to the study sites.
  12. Twilight on the main stream:  Because the mountain rivers flow through steep sided ravines, twilight comes early.
  13. View from above, Part 1:  You will see the river valley from a high ridge line above the forest canopy.
  14. View from above, Part 2:  A different view of the river valley showing the ravines that hold our study sites.

IV. Focal Stream experiments:

The core of our project is experiments done in four headwater streams which, prior to our experiment, contained only one species of fish.  We introduced guppies into a short section of each stream (80-150 meters).  The downstream side of the introduction site was defined by a barrier waterfall. The upstream dispersal of guppies was limited by another barrier waterfall.  We also study a “control” reach above the guppy introduction sites.
  1. Introduction to the experiments: An onsite introduction to our introduction experiments.
  2. Guppy foraging: An underwater video of the introduced guppies that shows the tattoos that we use to recognize them as individuals and how they feed.
  3. The artificial barrier on one focal stream:  In one case, there was not a natural barrier to the upstream dispersal of guppies, so we built one.
  4. Night time census of Rivulus hartii, featuring Brad Lamphere:  Rivulus is a killifish and is the only species that naturally occurs in these headwater streams.  We are studying them along side guppies because prior work shows that the have intense interactions with guppies and that Rivulus evolve in response to their interactions with guppies.
  5. Description of the experiment on one of the focal streams, featuring Steve Thomas: Dr. Thomas explains the experiment from the perspective of an ecosystems ecologist.
  6. Explanation of canopy clearing, featuring Steve Thomas:  We thinned the forest canopy in two of our four streams to increase light level and primary productivity.

V. Ecosystems Research on the Focal Streams:

We began to characterize the ecosystems of our experimental streams in what would become our guppy introduction site and the upstream control site a year before the guppy introduction.  We then introduced the guppies to the experimental stretch that was bounded by barrier waterfalls.  We continue to sample the introduction site and upstream control every other month to assess the impact of guppies on their environment.
  1. Introduction to stream ecosystems, featuring David Reznick:  Dr. Reznick explains how a stream ecosystem works and how it is different from a terrestrial ecosystem.
  2. Invertebrate sampling, featuring Keeley McNeil:  Ms. McNeil shows how we sample aquatic insects and other organisms that live on the bottom of streams.
  3. Invertebrate sampling, continued.
  4. Seston sampling, featuring Keeley McNeil:  Stream sediments contain fine and course organic particles, like bits of decaying leaves, that are an important part of the ecosystem.  Keeley shows how we sample them for later quantification.
  5. Loeb sampler, featuring David Reznick:  A critical part of the stream ecosystem is the algae and bacteria that live on the surfaces of rocks.  Dr. Reznick shows how this part of the ecosystem is sampled.
  6. The Nitrogen-15 drip study, featuring Steve Thomas:  We can characterize ecosystem dynamics by dripping this stable isotope of nitrogen into the water.  Primary producers like algae incorporate it into proteins, then the proteins move through the ecosystem as insects eat algae, fish eat insects, fish and insects die and decay, and so on.  We have used this method into an experimental tool to characterize how guppies alter their ecosystem.

VI. Guppy censuses:

Our experimental guppy populations were founded by fish that were individually marked and genotyped.  We do complete censuses every month in which we identify the survivors plus mark and genotype all fish born in the stream that are approaching maturity.  Here we show the entire process of the monthly census.
  1. On-site Introduction to census process: D. Reznick gives an overview of how the census is done.
  2. Collecting guppies, part 1, featuring Corey Handelsman and Andrew Furness: Corey and Andrew are seen collecting guppies, plus introduce themselves and explain their role in the project.
  3. Collecting guppies, part 2: Guppies in buckets and details on the early population growth of the introduced guppies.
  4. Collecting guppies, part 3, featuring Sarah Fitzpatrick and Justa Heinen:  More on the collection process and an introduction to Sarah’s and Justa’s role in the project.
  5. Snorkeling for guppies, featuring Sarah Fitzpatrick:  Sarah demonstrates how she catches the one that got away.
  6. Back in the lab: Our “assembly-line” processing of guppies, beginning with anaesthesia and ending with a photograph of each fish.
  7. Processing, part 2, featuring Justa Heinen:  We show how guppies are tattooed and scales are removed for future genetic analyses.
  8. Guppy release, part 1:  We show how the return of the guppies to their exact site of capture is organized.
  9. Guppy release, part 2, featuring Justa Heinen:  Justa shows the actual release process.

VII. Miscellany

1-3: Three short videos of a column of army ants that passed through our study site during the guppy census.  Such ant columns are a regular but dramatic feature of the tropical rainforest.  It is good to see them coming and to step aside.

  1. Army Ants
  2. Army Ants II
  3. Army Ants III
  4. Artificial streams:  We have an experimental facility that consists of 16 artificial streams, constructed alongside a natural stream, where we do short-term, replicated experiments. These experiments complement our focal stream experiments.
  5. Tour of the research station:  You will see the William Beebe Tropical Research Station, which is our home base for our research. It includes our labs and living facilities.  
  6. Foraging for avocados, featuring Ethan Brown:  We work in a landscape filled with abandoned crop trees that provide a source of food, for those willing to get it.
  7. Foraging for cocoa, featuring Keeley McNeil: Keeley has learned how to turn the raw pods into finished chocolate. Here you see the first step, which is climbing the tree to get the ripe pods.
  8. L’Orange Estate and the upper Aripo River:  This is an abandoned estate house, now owned by the Asa Wright Nature Center.
  9. Cook’s tree boa:  We see abundant and diverse wildlife in our work. This is a view of a snake crawling in the branches above the stream during a night time Rivulus census.

More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Career OpportunitiesUCR Libraries
Campus StatusDirections to UCR

Project Information

Foundations in Integrative Biological Research (FIBR)
Funded by: National Science Foundation

Email: gupy@ucr.edu

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