Download - 24-3 Feature Investigation
Cichlids• Fish from the Cichlidae family• Large diverse family
• Ex. Can be from 1 in to 3 ft long
• Between 1,300 and 3,000 species• New species are discovered annually
• One of the largest vertebrate families
• Found in Lake Malawi, Lake Victoria, and Lake Tanganyika with the most diversity• More than 1,800 species found
P. Pundamilia and P. nyererei Part of the Cichlid family
Belong to the same genus but are of different species
In certain locations the two species will not interbreed and act as two different biological species
In other locations the two species readily interbreed and produce fertile offspring
Interbreeding: mating between animals of different species that results in fertile offspring
Both live are in Lake Victoria
P. pundamilia Grayish on the top and
sides Dorsal fin is metallic blue
and red
P. nyererei Red-orange on the top Yellow on the sides
Both are black underneath and have black vertical stripes on their sides
An orange monochromatic light can hide their differences in color
Courtship The male swims towards the female
The male shows the side of his body to the female (lateral display)
When interested, the female will swim towards the male and the male will quiver
Introduction The researchers were Ole Seehausen and Jacques van
Alphen
Wanted to know the effects of male coloration in a female’s choice in a mate
Materials Four Pundamilia pundamilia male
Four Pundamilia nyererei male
Four Pundamilia pundamilia female
Four Pundamilia nyererei female
One fish tank
Two small glass enclosures
Orange monochromatic light
Procedure Put one female into the large tank and one male into each of
the small enclosures within the large tank The Combinations
P. pundamilia female with P. pundamilia male and P. nyererei male P. nyererei female with P. pundamilia male and P. nyererei male
Observe which male the female is drawn to under normal light compared to orange monochromatic light
Results Under normal light, females preferred males of their own
species P. pundamilia females with P. pundamilia males P. nyererei females with P. nyererei males
Under orange monochromatic light, the preference that females exhibited under normal light disappeared
The results show diversifying selection A type of natural selection that is in favor of the survival of
multiple genotypes that would create multiple phenotypes