Abstract
The distribution and the abundance of the giant African snail, Achatina fulica, were investigated in 1985 on Chichijima and Hahajima of the Ogasawara Islands. In these islands, the living snails were widely distributed in the areas affected by human impact, but relatively rare in the undisturbed areas. Dead snails were distributed more widely than living ones, partly owing to the secondary dispersion by the hermit crabs which utilize the shell of the snails. The density of the living snails was highest in such disturbed areas as residential or cultivated lands, and sea shore and forest margins along roads. The large snails (>80mm in shell height) were frequently found on the boundary between undisturbed and disturbed areas, but they were seldom observed within the latter. A natural enemy of the giant African snail, the predatory landsnail, Euglandina roses, introduced during the period of the U.S.A. occupation, was only found in Chichijima, but its density was low.