1.0 BACKGROUND OF THE STUDY
Snails are invertebrates (without bone), shell bearing animals that are passive or inactive during the day but, very active in the night, at dusk or when it rains and usually find in a cool place. Snail is a terrestrial animal of approximately 100,000 species of molluscs, of the phylum Mollusca, or alternately, any of the twelve species of land pulmonate gastropods used as human flood. It is air-breathing, usually herbivorous, with a complex hermaphroditic reproductive system, through demanding cross fertilization. It usually hibernates, forming a membrane over the shell opening (Akinnusi, 2004). Land snails move by gliding along on their muscular foot, which is lubricated with mucus and covered with epithelial cilia. This motion is powered by succeeding waves of muscular contractions that move down the ventral of the foot. They produce mucus to aid in locomotion by reducing friction. Snails also have a mantle, a specialized layer of tissue which covers al of the internal organs as they are grouped together in the visceral mass. The mantle is attached to the shell and creates it by secretion. Land nails need a good supply of calcium in the diet and environment to produce a strong shell. Snail can repair damage to its shell overtime of its living conditions improve, but sever damage can be fatal. Most land snails bear one or two pairs of tentacles on their head. In most land snails the eyes are carried on the first (upper) set of tentacles called ommatophores which are usually roughly 75% of the width f the eyes. The second (lower) set of tentacles acts as olfactory organs. Both set of tentacles are retractable in land snails.
Snail meat has been consumed by humans worldwide since prehistoric times. It is high in protein (12-16%) iron (45-60mg/kg), low in fat, and contains almost all the amino acids needed by human. A recent study has also shown that the glandular substances in edible snail meat causes aggulutination of certain bacteria, which could be of value in fighting a variety of ailments, including whooping cough. In west Africa, snail meat has traditionally been a major ingredient in the diet of people living in the high forest belt (The forested area other than savannah forest). International trade in snails is flourishing in Europe and North America. However, in spite of the considerable foreign and local demand, commercial snail farms such as those in Europe, South East Asia and the Americas hardly exist in Africa. In Ghana, Nigeria and Cote d’Ivoire where snail meat is particularly popular, snails are gathered from the forest during the wet season. In recent years, however, wild snail populations have declined considerably, primarily because of the impact of such human activities as deforestation, pesticide use, slash and burn agriculture, spontaneous bush fires and the collection of immature snails. It is therefore important to encourage snail farming (heliculture) in order to conserve this important resources.