The BasicsCichlids, Pundamilia pundamilia vs. Pundamilia nyererei, and Courtship

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

P. pundamilia P. nyererei

P. Pundamilia(top) and P. nyererei (bottom) under the orange monochromatic light

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

The ExperimentIntroduction, Hypothesis, Materials, Procedure, Results, and Conclusion

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

Hypothesis Female African cichlids choose mates based on the

coloration of males

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

The experiment under normal light conditions

The experiment under the 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

Conclusion Similar light conditions in their native habitats may be the

reason why sometimes they interbreed and sometimes they do not

This type of sexual selection could divide a large population into smaller populations

The separate populations could eventually become distinct species