THE VARIED ROLES OF SNAILS - National Universities Commission

1925, 1931, at Angola and Namibia; Connolly and Degner,
in 1934, worked in West Africa on Edible Land Snail. In
Nigeria, Ajayi et al (1974); Akinnusi (1998), Hodasi (1973,
1982), Imevbore and Ajayi (1988), Okafor (1990, 2001)
did intensive work on the biology, ecology and production
of both land and freshwater snails.
The total number of land snails in Africa is estimated to be
about 6000 and these were found to belong to about 34
families. Of these about 189 genera are fully identified;
80% of these are recognized as endemic to the continent.
However, it is known that of all these only 3 families
dominate and have their endemic genera all over Africa.
These include, Subulinidae, Achatinidae and Urocyclidae.
The Achatinidae have about 23 genera of which 9 or 39%
are endemic to West Africa. For the other 2 families,
Subulinidae contains 21 genera with 6 or 18% are endemic
to Africa. The zoogeographical analysis of land snails
species isolated four areas of endemism in Africa namely;
(a) Southern Africa
(b) Northeast Africa
(c) Eastern Africa
(d) Central and West Africa (See table below).
The central and West African zone represents the largest
continuous forest refugium in Sub-Saharan Africa. This
area has the greatest numbers recorded in Cameroun and
Gabon. These two countries still represent the single most
important area in Africa in terms of diversity of land
mollusks. There are other three minor forest refugia
namely:
(a) Niger Delta (in Nigeria)
(b) In Ghana and Ivory Coast
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