Evaluation of anaesthetic effects of aqueous bark extract of <i>Tephrosia vogelii</i> on an African catfish <i>Heterobranchus longifilis</i> post junveniles val. (pisces: 1840) as a tranquilizer

Abstract

This work was designed to investigate the potency of aqueous bark extract of Tephrosia vogelii as a tranquilizer on eterobranchus longifilis, the concentration at which the fish is completely tranquilized and the recovery time of the extract. Fresh samples of T. vogelii bark were collected, air-dried under a shade for 21 days and oven-dried at 60oC for 3–4 hours to constant weight. The dried samples were pulverized using an electric kitchen blender and stored in air tight bottles for subsequent use. Parts of the dried samples of T. vogelii bark were used to carry out phytochemical analysis to determine their chemical constituents. The bark was extracted in aqueous medium for the purpose of this experiment. The result of the sedation of Heterobranchus longifilis with the aqueous bark extract of Tephrosia vogelii showed that all H. Longifilis juveniles injected with the aqueous bark extracts were tranquilized up to anaesthetic stage 3 (light sedation). None of the experimental fish was able to enter anaesthetic stage 4 (deep) anaesthesia. The aqueous bark extract was found to have a significantly shorter (P<0.05) induction time of 52.33 seconds with a short recovery time of 125.33 minutes at concentration 0.01g/l at anaesthetic stage 3 depicting that the aqueous bark extract of T. vogelii has the high potency of a tranquilizer.

Keywords: Heterobranchus longifilis, Aqueous Leaf Extracts, Anaesthetic, Tephrosia Vogelii, Tranquilizer