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

Anthony I Okafor

doi:10.5296/jbls.v5i1.5213

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.

Highlights

IntroductionThe African lungfish, Protopterus is amphibious using its gills to absorb oxygen whilst immersed in water and its lungs for absorption of atmospheric oxygen.(Okafor,2012)It inhabits shallow and swampy parts of some Rivers and Lakes of some African countries during the wet season (Giusi et al, 2011; Icardo et al, 2011,2012; Laberge and Walsh, 2011;) during the dry season, when the ambient water has totally dried up, Protopterus excavates a burrow in the soil where it resides in a dormant state until the end of the season. (Okafor et al 2011; Loong et al, 2012 a,b).The life history of P. annectens of West Africa has been detailed by Johnels and Svensson (1954)
The mean Branchiosomatic indices (BSI) and Pulmosomatic indices (PSI) within various ranges of standard length of P. annectens as well as the mean body weights within those ranges are presented in Tables 1, 2, and 3 corresponding to specimens procured from Ogurugu, Otuocha and Nsugbe sampling stations respectively of Anambra River
If the fingerling stage of the specimens obtained from Ogurugu station was taken as a reference, mean BSI was as high as 0.96 while mean PSI was as low as 0.32

Summary

Introduction

The African lungfish, Protopterus is amphibious using its gills to absorb oxygen whilst immersed in water and its lungs for absorption of atmospheric oxygen.(Okafor,2012)It inhabits shallow and swampy parts of some Rivers and Lakes of some African countries during the wet season (Giusi et al, 2011; Icardo et al, 2011,2012; Laberge and Walsh, 2011;) during the dry season, when the ambient water has totally dried up, Protopterus excavates a burrow in the soil where it resides in a dormant state until the end of the season. (Okafor et al 2011; Loong et al, 2012 a,b).The life history of P. annectens of West Africa has been detailed by Johnels and Svensson (1954). The African lungfish, Protopterus is amphibious using its gills to absorb oxygen whilst immersed in water and its lungs for absorption of atmospheric oxygen.(Okafor,2012). It inhabits shallow and swampy parts of some Rivers and Lakes of some African countries during the wet season (Giusi et al, 2011; Icardo et al, 2011,2012; Laberge and Walsh, 2011;) during the dry season, when the ambient water has totally dried up, Protopterus excavates a burrow in the soil where it resides in a dormant state until the end of the season. The present study aims to fill this gap in knowledge by seeking to define more precisely the relationship between the gill weight and lung weight in various sizes of the African lungfish P. annectens of Anambra River, Nigeria

Methods

Results

Conclusion