Acute-lethal toxicity (LC₅₀) effect of <i>Moringa oleifera</i> (Lam.) Fresh Root Bark Extract on Oreochromis niloticus Juveniles Under Renewal Toxicity Exposure

Abstract

Acute-lethal toxicity is a tool used in piscicide bio-safety assessment in fish farming prior to its proper application in sustainable aquaculture. Piscicides of plant origin are usually considered for bio-safety assessment because of their effects on non-target aquatic species in fish pond. Acute-lethal toxicity is an indication of baseline data assessment before any piscicide of plant origin could be used in sustainable aquaculture. This study assessed the acute-lethal toxicity (LC₅₀) effect of Moringa oleifera fresh root-bark extract on fresh water fish, Oreochromis niloticus juveniles for 96-h under renewal toxicity exposure. Median Lethal Concentration (LC₅₀) for O. niloticus juvenile was 97.61 mgl^-1 and high mortality was obtained at 200 mgl^-1 where fish showed abnormal behaviour such as erratic swimming, mucus secretion, loss of scales, haemorrhages, and stiff fin rays prior to death. Fresh root-bark extract of M. oleifera could serve as pond management tool in aquaculture to assess bio-safety level of targeted and non-targeted aquatic organisms in pond.

Keywords: Moringa oleifera, Acute Toxicity, Freshwater fish, Piscicide.