The Lung-Fish Protopterus In Central Africa, South of The Zambezi

Abstract

Seven specimens of Protopterus from the Sabi Valley, Southern Rhodesia are described. Comparison with previous descriptions shows that these belong to the species P. annectens (Owen), of which a few specimens have been found previously in the Zambezi River Basin. It is likely that these specimens are from a population of P. annectens (Owen) which can be separated statistically by rib number from populations of P. annectens (Owen) in West Africa. The present specimens have rib numbers intermediate between those of P. annectens (Owen) from West Africa and P. amphibius (Peters) from Kenya and Tanganyika. The description of P. amphibius (Peters) from specimens collected at Quelimane on the Zambezi estuary has rested largely on differences in the number of ribs in comparison with specimens of P. annectens (Owen) from the same locality. Specimens of P. annectens (Owen) described here show that this distinction can no longer be maintained, and the possible occurrence of P. amphibius (Peters) as revised by Trewavas (1954) in the lower Zambezi and district must be regarded as uncertain. These fish present difficulties in subspecific taxonomy. Two groups of fish showing consistent differences in respect of a meristic character might be given subspecific rank.