The Relationship between Branchiosomatic and Pulmosomatic Indices in the African Lungfish, Protopterus Annectens of Anambra River, Nigeria

Abstract

The relationship between Branchiosomatic indices (BSI) and Pulmosomatic indices (PSI) in various sizes of the African lungfish, Protopterus annectens procured from Anambra River was determined. There was an inverse relationship between BSI and PSI. Mean BSI exhibited highest values of between 0.90 and 0.96 in the fingerlings, then began to decrease as the fish grew until it reached minimum values of between 0.36 and 0.44 in the large sized P. annectens. Conversely, mean PSI showed minimum values of between 0.32 and 0.48 in the fingerlings, then rose to a peak of between 0.88 and 1.06 in the large sized P. annectens. The study tends to support the palaeontological evidence which states that the Amphibians evolved from some now extinct fish groups related to the lungfishes during the Devonian period.