Van Steenberge, M. & Snoeks, J. 2010. ‘Morphological study on similar Tropheus populations occurring on opposite shorelines’. Cichlid Science 2010. Book of abstracts. Basel : University of Basel.

Conference abstract

In comparison with the species flocks of Lake Malawi and Victoria, the taxonomy of the estimated 250 species of Lake Tanganyika cichlids is relatively well known. Many species, however, show a considerable amount of geographical variation, with distinct populations displaying a different colour pattern. The genus Tropheus Boulenger, 1898 offers the prime example of this phenomenon as almost every stretch of uninterrupted rocky shore is colonised by one of its many colour morphs. The taxonomy of Tropheus, with six described species, is confusing and, for a long time already, in need of revision. Our goal is to make a revision of the genus Tropheus, using both traditional and modern morphological methods, with a complementary focus on the taxonomic value of colour patterns and taking into account recent molecular results. Although the Royal Museum for Central Africa harbours by far the largest collection of Tropheus specimens, only some old collections originate from the western lakeshore as large sections of the Congolese coast (consisting of nearly half of the lake’s shoreline) have remained unexplored. Therefore, a sampling trip was organised in the spring of 2010 to the western and north-western shores of Lake Tanganyika. This allowed us to collect specimens of different Tropheus populations from both known (type) localities as from previously unexplored sites. We will discuss the first results obtained from this expedition, including a morphological comparison between supposedly conspecific populations, occurring both on the eastern and western shores.