1. If being flashy and colorful attracts predators, why do you think guppies are so colorful?
They are colorful because flashy colors attract mates. (If less colorful guppies were bred together, however, we could create a new kind of guppy that can hide from predators more easily!)
2. After viewing the guppy gallery, pick the fish you find most interesting. What is the fish’s scientific name, origin and average size? Describe the coloration of the fish you chose.
The Poecilia reticulata is a Brazilian guppy that is about 1.4" long. It's black with noticeable spots of yellow and white, as well as a red spot on its dorsal fin. Its tail fin is green.
3. After viewing the predator gallery, pick the fish you find most interesting. What is the fish’s common name, scientific name, and origin?
The pike cichlid, also known as the Crenicichla alta, is a 12" long fish that originated in Latin America. It's completely pink, but has some flecks of white along its back, and has a prominent black spot just above its fin.
4. View the guppy’s habitats, what habitat conditions would affect the predator populations?
The shallow pool would be hard for predators to find their way into. The dam restricts predator movements.
5. Who is John Endler? What did he study and where did he study it?
John Endler is an evolutionary ecologist. He studied guppies in Trinidad and rediscovered a species.
6. For each of the three stream areas, describe the guppy coloration.
Pool one has brightly-colored guppies with large spots. Pool two has medium-colored guppies with medium-sized spots. Pool three has drab guppies with small spots.
7. Develop your own hypothesis about guppy coloration. The hypothesis should answer why guppies in different areas of the stream have difference in coloration. (You can choose from the list on the simulation, or make up your own)
"Predators are causing guppy populations to become more drab by preying on the most brightly-colored individuals and eliminating them from the gene pool.
Trial 1
Guppy: Even Mix
Predators: 30 Rivulus
Brightest guppies: 48%
Bright guppies: 43%
Drab guppies: 7%
Drabbest guppies: 3%
Trial 2
Guppy: Even Mix
Predators: 30 Rivulus, 30 Acara
Brightest guppies: 7%
Bright guppies: 73%
Drab guppies: 20%
Drabbest guppies: 0%
Trial 3
Guppy: Even Mix
Predators: 30 Rivulus, 30 Acara, 30 Cichlid
Brightest guppies: 0%
Bright guppies: 0%
Drab guppies: 0%
Drabbest guppies: 100%
Trial 4
Guppy: Mostly Bright
Predators: 30 Rivulus
Brightest guppies: 83%
Bright guppies: 13%
Drab guppies: 4%
Drabbest guppies: 0%
Trial 5
Guppy: Mostly Drab
Predators: 30 Rivulus, 30 Acara, 30 Cichlid
Brightest guppies: 0%
Bright guppies: 0%
Drab guppies: 0%
Drabbest guppies: 0%
8. Describe how predators influence guppy coloration.
With the rivulus fish and the acara fish, the brightly colored guppies were easily able to survive. However, with the mix of cichlid, only the drab population survived.
9. Was your hypothesis correct, use your data to justify your answer.
Partly. In some trials, only the bright guppies survived. Note that said trials used weaker fish.
10. What does it mean that “male guppies live in a crossfire between their enemies and their would be mates”?
It means male guppies will either have to A) use their bright colors to attract mates, but risk being attacked by predators or B) use their drab colors to hide from predators, but have a lesser chance of attracting a mate.
11. Why do you think guppies in different areas of the stream have different coloration?
They have different coloration due to the predators that dwell there. With weaker predators, the bright-colored guppy population is still prominent, while areas with stronger predators has only drab-colored ones.
12. What would happen to mostly drab guppies that were placed in a stream with very few predators?
They would thrive, because the predators would not notice them.
13. What would happen to brightly colored guppies that were placed in a stream with many predators?
They would not live for very long, because their flashy colors would attract predators.
