Aspects of Habitat Ecology of Macrobrachium vollenhovenii (Herklots, 1857) on the Lower Volta River, Ghana

Abstract

Water quality parameters, river sediment texture, percentage abundance of species, fish and plants associated with the habitat of African giant prawn, M. vollenhovenii (Herklots, 1857) were studied at the Eastern Region of Ghana on Lower Volta River Basin Channel between June- 2015 and May- 2017. Analysis of the physico-chemical properties revealed a low level of seasonal fluctuations as obtained values for pH, salinity, temperature, ammonia and phosphates were not significantly different (p>0.05) based on seasonality. Results of this study revealed that most water quality parameters including heavy metals ions were within the thresholds recommended for surface water and fresh-water fish aquaculture except for K+, Ca2+, Cu2+, Zn2+ and Pb2+ ions. The river sediments’ texture was sandy loam with low organic matter percentage compositions and an average pH value range (4.96±1.33-5.33±0.95) which is weakly acidic. The water depths across the sampling locations ranged between 5.13±2.6fts and 15.80±4.92 fts and showed that the prawn is a sub-lithoral animal. Catch statistics revealed higher percentages of males at both seasons. Oreochromis niloticus, Parachana obscura and Atya gaboniensis were found foraging with M. vollenhovenii; while Eichhornia crassipes, Ipomoea aquatica, Diplazium sammatii and Leptochloa caerulescens were flora species providing hiding spots for M. vollenhovenii in this habitat. Conclusively, M. vollenhovenii population around this study location inhabits an exclusively fresh-water ecosystem which can be simulated for captive culture of this prawn. Aquaculture of this prawn is therefore recommended.