Some female cichlids value territory quality so much that they are willing to mate with males of a different species, a recent study published in the journal Behavioral Ecology and Sociobiology has found.
Peter Dijkstra, Els van der Zee and Ton Groothuis studied the mating preferences of female Pundamilia nyereri, a Lake Victoria haplochromine cichlid.
Using wild-caught individuals and first-generation laboratory-bred offspring, they first demonstrated that dominant males of Pundamilia nyererei and P. pundamilia preferentially occupied a large PVC tube (15 cm diameter) relative to a small tube (5 cm diameter) as territory.
The tubes mimic a rocky crevice serving as a spawning location in a male s territory, with the expectation that a large tube mimicking a large crevice would correspond to a relatively high-quality territory.
The authors next conducted mate choice experiments, in which females of P. nyererei were offered males of both P. nyererei and P. pundamilia (males of both species have different breeding colours) in three situations: (1) both species with the small tubes; (2) P. nyererei with large and P. pundamilia with small tubes; (3) P. pundamilia with large and P. nyererei with small tubes.
When offered both species of males with small tubes and the P. nyererei males with large tubes, the female P. nyererei chose to mate with conspecific males significantly more often.
However, when offered a male P. pundamilia occupying a large tube and a conspecific male occupying a small tube, female P. nyererei showed a significantly diminished preference for conspecific males, preferring to mate with P. pundamilia males (although this preference was not statistically significant).
The authors thus demonstrated that territory quality influences mate choice and can override the female preference for conspecific male nuptial colouration in Pundamilia.
They speculate that the reasons for the female doing so are firstly, gaining ...indirect benefits by mating with a male with a high-quality territory, because owning such a territory may honestly signal superior genetic or phenotypic quality... and secondly, accruing ...potential direct benefits from choosing a large crevice, as it may provide better shelter during the courtship and spawning event.
For more information, see the paper: Dijkstra, PD, EM van der Zee and TGG Groothuis (2008) Territory quality affects female preference in a Lake Victoria cichlid fish. Behavioral Ecology and Sociobiology 62, pp. 747"755.