Two new barbine species are described from the South Rukuru River, which flows into Lake Malawi. ‘
Barbus’
seymouri
sp. nov. differs from the ‘
B’
eutaenia
/ ‘
B’.
miolepis
species complex in the absence of the sheath of enlarged scales at the base of the dorsal fin, which is prominent in the other species of the complex, and in the pigmentation pattern of the mid-lateral stripe.
Labeobarbus nthuwa
, sp. nov. differs from
L. marequensis of the Middle and Lower Zambezi River system and from
L. johnstonii of the Lake Malawi system in the presence of a bony dorsal spine, and from
L. codringtonii of the Upper Zambezi in the absence of the tall dorsal fin. It also differs from
L. johnstonii in scale counts, and from
L. marequensis in gill raker counts and caudal peduncle proportions. The fish fauna of the South Rukuru River is separated from that of Lake Malawi and all other inflowing rivers by steep rift escarpment waterfalls. Evidence is presented for river capture from the Luangwa River, which flows to the Middle Zambezi. Other Zambezian species found on the northern Malawi lakeshore are considered to be evidence for a separate, former link to the Zambezi system via the Chambeshi system.
