In the guppy (Poecilia reticulata), a South American fish, males have a pattern of colorful and very variable spots.
In the guppy (Poecilia reticulata), a South American fish, males have a pattern of colorful and very variable spots. Guppies from streams inhabited by their major fish predator (Crenicichla) have smaller, less variable, and less contrasting spots than guppies inhabiting streams that lack this predator. A scientist, John Endler, mixed a sample of zoo guppies […]