Guppies and Natural Selection

Being flashy and colorful attracts mates as well as predators.  Camouflage can hide you from predators and potential mates, so camouflage is good to an extent.

My favorite guppy's scientific name is poecilia reticulata.  It is from Brazil and grows to approx. 3.5 cm.

My favorite predator fish is in Trinidad and Latin America, grows to about 16", and its scientific name is Hoplerythrinus unitaeniatus.  It is the Golden Trahira.

Habitat conditions that would affect predator populations is a natural dam, as small fish could fit through, but the larger predators would run out of food.

John Endler was a biologist and studied diversity in coloration of guppies in Trinidad.

Observations about pool coloration:

Pool 1: Blue and orange splotches on their sides, with bright coloration and large spots.
Pool 2: Average coloration, with medium-sized spots.
Pool 3: Average coloration with small spots.

I believe all of the guppies need to balance the predators in the area (by becoming more drab), and need to pass on their genes (with causes more vivacity), so more predators will cause more drabness, and more females and less predators, and this will vary slightly because no two pools are exactly the same.

Predators influence guppy coloration because they eat the brighter ones.

Yes, my hypothesis was correct. As more varieties of predators were introduced, then more were drab. If only rivulus were introduced, then the bright guppies would become completely dominant.

Male guppies live in a crossfire between mates and predators because mates want brighter colors, but predators eat the brighter guppies.

Guppies in the different areas have different coloring because of the certain predators in those pools favor different colorings.

If mostly drab guppies were placed in a pond with few predators, the guppies would become brighter and the population would explode.

If mostly bright guppies were placed in a stream with many predators, the population and coloration would level out.