THE VARIED ROLES OF SNAILS - National Universities Commission

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(c) In Liberia and other parts of the tropical rainforest, and the Guinea Savannah, forest mosaic in Nigeria. The population of edible land snails is high in the wild and because the people of Africa are beset with acute protein shortages many people tend to eat a lot of snails to assuage the acute shortage. The known nutritive value of the snails makes it unthinkable not to harness it for human benefits in view of the acute shortages. In most areas, the land snails and some aquatic forms (e.g. the prosobranchs) are collected indiscriminately by the rural people for their family consumption on a daily basis. However some collect them to sell in the local markets from where they find their way to the urban markets. Our studies show that edible snails are also consumed in Europe and North America. In these places the snails are sold in shops and restaurants. The traditional European species of what they call “Escargots” is relatively small and slow at growing, so the demand for snail meat which has tremendously grown over the years has been partially satisfied by importation of the fleshy giant African land snails, “Escargot achatine”. The commercial success of farm ranching Escargot achatine may be appreciated by the observation that as far back as 1977, over 1,500 tons of canned snail meat, worth US $3 million was shipped into Europe from Taiwan alone. The giant African substitutes are said to be slightly inferior in quality to the European edible snails because it is “rubbery” and too often have “swampy-tastes”. This quality disadvantage is usually addressed by flavouring the 62
meat with garlic. British species are also well accepted as meat in most countries. It is now known that edible snails can be farmed using different pen systems, Cages and Tanks. The snails have high biotic potentials and large net reproductive rates (Ro) and so have the capacity to thrive well in captivity. The can feed on a large variety of readily available plant food materials. It has been proven that rearing the snails in captivity helps in sustainable supply of snail meat to meet the increasing demand for snail meat and in conserving these animals. The adult grow up to 200mm and weigh about 250g. <strong>THE</strong> KNOWN EDIBLE SNAIL SPECIES In Africa and Europe, the following are edible snails. Besides the species listed there are many more species in many countries of the world. Table: 3: List of Land Snail Families from Africa S/No Families Genera in Africa Endemic Genera 1. Maizaniidae 3 3 2. Cyclophoridae 4 3 3. Pomatiasidae 2 2 4. Hydrocenidae 1 - 5. Veronicellidae 3 2 6. Orculidae 2 2 7. Chondrinidae 1 - 8. Pupillidae 4 - 9. Valloniidae 2 - 63
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THE VARIED ROLES OF SNAILS (GASTROP
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1820 and twice that in 1930 (Martin
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contributions of snails to human ex
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a.) Production from the wild (wild
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Gastropods I: Terrestrial or Garden
Page 11 and 12: contracts and expands and this crea
Page 13 and 14: live on the surface so that they ca
Page 15 and 16: Many members of the Carrier shell f
Page 17 and 18: Most bivalves reproduce by laying m
Page 19 and 20: the snails, what is true of one spe
Page 21 and 22: principle, is a rasping tongue with
Page 23 and 24: sculptural defenses against crushin
Page 25 and 26: Fig. 6: Shells of different freshwa
Page 27 and 28: ight larval retractor i.e. establis
Page 29 and 30: (iii) The hypertrophy of the right
Page 31 and 32: ys two present kidneys 5. Operculum
Page 33 and 34: organs of some species and found si
Page 35 and 36: imperative for the ecosystem dynami
Page 37 and 38: oth of a direct and an indirect nat
Page 39 and 40: females.. Self fertilization is a c
Page 41 and 42: emerges and goes on a binge of repl
Page 43 and 44: of spermatozoa in males or stimulat
Page 45 and 46: d. LIFE CYCLE & LIFE BUDGET SUDIES:
Page 47 and 48: competitively loosely packed. With
Page 49 and 50: digestible vegetable. Tough plants
Page 51 and 52: Birds Various ducks Storks Kites Ot
Page 53 and 54: when mineral ions form chelate comp
Page 55 and 56: produce stress. Thus snail distribu
Page 57 and 58: Protein (g): 16 Availablecarbohydra
Page 59 and 60: or cocoyam, and palm oil or pea nut
Page 61: 1925, 1931, at Angola and Namibia;
Page 65 and 66: 4. Helicinidae 5. Fissurellidae 6.
Page 67 and 68: Helix nucuea Helix aperta Arianta a
Page 69 and 70: Archachatina calachatina marinae Ar
Page 71 and 72: sites in North Africa but are also
Page 73 and 74: infect man or animals. The five pri
Page 75 and 76: Okafor (1989, 1990, and 1992), Ozum
Page 77 and 78: P. aurita P. byronensis Gyraulus G.
Page 79 and 80: one miracidium the potential of pro
Page 81 and 82: In the snail the miracidium metamor
Page 83 and 84: While Potadoma and Semisulcospira s
Page 85 and 86: Clonorchiasis is caused by Clonorch
Page 87 and 88: Table 7: Showing a list of trematod
Page 89 and 90: promising and show reduction of pai
Page 91 and 92: memory loss have a devastating cons
Page 93 and 94: acteria. This bacteriostatic activi
Page 95 and 96: The thin, quickly leached soils of
Page 97 and 98: Snails are also pests of crops wher
Page 99 and 100: (f) The management of the snail far
Page 101 and 102: flakes or maize chaffs and mostly g
Page 103 and 104: important that they are separated i
Page 105 and 106: The profit = 1, 800,000 - 30,000 =
Page 107 and 108: designs that are very attractive an
Page 109 and 110: cornuarietis or of flatworms as bio
Page 111 and 112: In few location of the world, snail
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damages to crops. So, they must be
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115
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The Nigerian Field, 44 (4), 130-144
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19. Asibey, E. O. A. and child, G.
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32. Dei, G. J. S. (1989). Hunting a
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J. moll. Studies, 64 (2), 173-181.
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56. Lux moore, R. (1985). Game farm
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69. Okafor, F. C. (1989). Consumpti
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Proc. Symposium organized by the Br
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Chronicle Nautilus Batavia, 104,278
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Achatina fulicaBowdich,1822 Shell s
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Achatina immaculata Lamarck,1822 Sh
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Achatina stuhlmanni von Martens,189
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Columna leai(Tryon, 1866) : São To
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Shells of Gyraulus costulatus 141
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Shells of Biomphalaria pfeifferi 14
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Shells of Lanistes varicus and oper
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147
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Courtesy of Yurii Yashin Courtesy o
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Yurii Yashin Yurii Yashin Yurii Yas
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