Barbus radiatus is a widely distributed, polytypic species with three recognized
subspecies: radiatus Peters (1853), aurantiacus Boulenger (1910), and
profundus Greenwood (1970). A phenetic analysis of relative similarity was conducted
for specimens of B. radiatus from throughout its known range. The study focuses on
several large population samples taken recently along the presumed central Zambian interface
between the subspecies aurantiacus and radiatus. New data on meristic and
morphometric variation in B. radiatus and recent rediscovery of typical
radiatus in Lake Victoria demonstrate that profundus is a species distinct from
radiatus. With respect to the remaining two subspecies, results indicate a
populational mosaic of highly variable morphs rather than two discrete, allopatric morphs.
Thus, aurantiacus is placed in synonymy of radiatus. It is hypothesized that
the populational mosaic of morphology in radiatus reflects adaptive ecotypic responses
to water temperature and current velocity. The characters which accounted for most of the
geographic variation of radiatus were body depth, caudal peduncle length, longitudinal
meristic counts, dorsal fin height, and orbit diameter.