Biol. Lett. (2006) 2, 548–552 received comparatively little attention (West & doi:10.1098/rsbl.2006.0532 Michel 2000). One overlooked LT species flock Published online 12 September 2006 includes seven species of Synodontis catfish, six of which are endemic (Poll 1971), which is com- parable to other small LT radiations (Coulter On the origin of the 1991). Synodontis (ca 116 described species) are distributed throughout tropical Africa, but of the Synodontis catfish species other Great Lakes, only Lake Malawi (LM; 4–5 Myr old) harbours one (possibly two; Snoeks 2004) ende- flock from Lake Tanganyika mics, while Lake Victoria (LV; 12 400 kyr) has two Julia J. Day1,2,* and Mark Wilkinson2 non-endemics. LT cichlids are both polyphyletic, implying inde- 1Division of Biology, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, UK pendent colonizations of the lake, and paraphyletic, 2Department of Zoology, The Natural History Museum, demonstrating that radiations within the lake have Cromwell Road, London SW7 5BD, UK subsequently become a source for secondary seeding *Author for correspondence (
[email protected]). of rivers and younger lakes (Salzburger et al. 2002). Species flocks within Great Lakes provide In contrast, Platytelphusidae crabs (Marijnissen et al. unique insights into the factors affecting diversi- 2006)andCleopatra gastropods (West & Michel fication. Lake Tanganyika (LT) is of particular 2000) are monophyletic, consistent with single interest because it contains many endemic origins and no dispersal out of Tanganyika. A groups for which general factors affecting diver- current phylogeny is lacking for East African sification can be discerned. Here, we present the Synodontis and thus it is not known whether the LT first phylogenetic study of the LT Synodontis (Siluriformes, Mochokidae) species flock using species flock is a single radiation.