Muscle deoxyribonucleic acid (DNA) concentration response to sublethal effect of ethanol extract of Nicotiana tobacum on juvenile African catfish (Clarias gariepinus)

Abstract

Advancement in human knowledge in the utilization of available natural resources to effect positive changes, though useful in achieving the desired purpose, but if not effectively regulated and monitored, may sometimes present undesired side challenges. The quest to achieve nutritional sufficiency to the ever increasing human population through fish production is not left out in this phenomenon. To this effect, this research is meant to understand the muscle deoxyribonucleic acid (DNA) concentration response to sublethal effect of ethanol extract of Nicotiana tobacum on juvenile African catfish (Clarias gariepinus). Experimental fish were acclimatized for 14 days before bioassay and ethanol extract of tobacco leaf (Nicotiana tobacum) was made. Central composite design (CCD) in response surface method was applied to make a design matrix consisting of five design points per parameter or study factor. The study factors include exposure time, extract (pollutant) concentration and fish quantity per aquaria. Maximal effect condition as well as significant interactions were obtained and presented in contour and three dimensional plots. Individual effect of process conditions were studied as well. From the central composite design (CCD), process condition that has the maximum effect on DNA concentration in the fish muscle is; exposure time at 120 hours, extract concentration at 0.25 mg/l and fish quantity at 6. It was observed from the study on individual effects, that the process factors caused reduction in muscular DNA concentration of the African catfish (Clarias gariepinus).