Comparative Toxicity Assessmentof Aqueous and Ethanolic Bark Extracts of Mahogany: Khaya grandifoliolaon Mangrove Periwinkle; Pachymelania aurita

Abstract

The acute toxicities of extracts of Bark of Mahogany (Khaya grandifoliola) in aqueous and ethanolic solutions were evaluated against the edible periwinkle (Pachymelania aurita) in laboratory bioassays. From the derived toxicity indices, the aqueous extract (96h LC₅₀ = 17.4ml/L, 3.48g/L) was found to be 24.2 times less toxic than the ethanolic extracts (96h LC₅₀ = 0.24ml/L, 0.144g/L). ANOVA showed significant differences in the response of Pachymelania aurita to different concentrations of exposure to extracts at 48hr, 72hr and 96hr respectively. Symptoms of toxicosis observed in the test organisms were immobility and eventually death.

Keywords: Toxicity, Pachymelania aurita, Khaya grandifoliola, Edible periwinkle, Lagos lagoon.

DOI: 10.7176/JBAH/10-7-02

Publication date: April 30^th 2020