The territorial behaviour of a small rock-dwelling cichlid, Pseudotropheus aurora,
was studied at Thumbi Island West at the southern end of Lake Malawi. P. aurora
is one of several species that have been introduced to an already diverse fish community.
Many of the endemic and introduced species are highly territorial. The coexistence of an
introduced territorial species within a species-rich community of other territorial species
examined. Territories from which P. aurora individuals were removed were invariably
re-occupied by conspecifics. Similarly, when all territories of a certain area were
emptied of all territory owners of any existing species, the former P. aurora
territories were re-occupied by conspecifics. The possible roles of site specificity,
competitive exclusion and behaviourally transmitted traditions regarding territories
are discussed.