Research article

Evaluation of Ichthyotoxicity Activity of Raphia farinifera (Gaertn.)Hyl. (Arecaceae) Fruits Extract

Cletus Anes Ukwubile¹*, Otalu Otalu Jnr ²,  Balogun Joshua Babalola

¹ Department of Biological Sciences, Ahmadu Bello University, Zaria Nigeria

² Department of veterinary Public Health, Ahmadu Bello University, Zaria, Nigeria.

³ Department of Pharmacognosy and Drug Development, Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria, Nigeria.

*Corresponding Author E-mail: doccletus@yahoo.com

Accepted 17 February 2013

Abstract

Harvesting of fish in Nigeria by local artisans is done in various ways. One of these ways is the use of plant extract as poison to kill fish in various fresh water habitats. This research was conducted in order to evaluate in detail fish poisoning potentials (Ichthyotoxicity) of Raphia farinifera aqueous fruits extract. Ripped fruits of R. farinifera were harvested from raffia palm tree, and soaked in water for 7 days to enable them decay properly so that the brown-reddish imbricate scales covering the ovoid glossy fruits can be removed from the fruits, thus exposing the yellowish fruits. After this, the fruits were pounded into coarse form using local mortar in water, and covered with polythene for 48 hrs. The yellowish solution from the polythene was collected into a beaker, evaporated into dryness and tested for phytochemical constituents, while the coarsely pounded fruits were tightly covered for use. Preliminary phytochemical screening of the extract solution showed that it contained saponins, alkaloids, tannins, flavonoids and anthraquinones. Coarsely pounded fruits sprayed into various basins containing different species of fresh water fish produced 100 % mortality rate in dose dependent fashion in all the fish families. Surface dwelling fish like Oreochromis niloticus (Cichlidae), Gnathonemus petersii (Mormyridae), Hippopotamyrus psittacus (Mormyridae), Labeo parvus (Cyprinidae) and Tilapia zillii (Cichlidae), were mostly affected by extract, than the bottom dwellers like Protopterus annectens (Protopteridae), Gymnarchus niloticus (Gymnarchidae), and Heterobranchus longifilis (Clariidae). Toxicity studies showed that aqueous extract of Raphia farinifera fruits is used as fish poison (Ichthyotoxicity), it thus serve as an alternative means of harvesting fish locally from Nigeria fresh water.

Keywords: Ichthyotoxicity, Raphia farinifera, Fresh water, Phytochemical, Doses