Optimal stocking densities of snails [Archachatina marginata saturalis Swainson)]in the swamp forest zone of Nigeria

Abstract

Optimal stocking densities of breeding and fattening snails [Archachatina marginata Saturalis A.m.s (Swainson)] were determined through two experiments (five treatments, four replicates and randomised complete block design each) between April and December 1998.Experiment 1 had 3,6, 12, 17 and 22 A.m.s. adult snails per cage of 6ocm by 42cm. Treatments 1 to 111 with mortalities of 0.0, 6.4 and 7.3% were not significantly different (P> 0.05) from each other but were better and significantly different (P<0.05) from treatments IV and V (7.9 and 9.7% respectively). Clutch size and percentage hatchability of eggs were not significantly different (P>0.05) between the treatments. 5 snails per cage was uneconomic. 6 to 12 snails per cage (22 to 44 snails per m2) was recommended as the optimal stocking density of breeding snails of A.m.s. Experiment II had 2, 3, 4, 5 and 6 A.m.s. fattening snails per cage of 20cm x 20cm.Treatments I to III with mean daily weight gains of 3.3g, 2.6g and 3.0g mean feed conversion ratios of 3.9,6.3 and 6.0 and mean shell length gains of 1.7, 0.9 and 0.9mm were not significantly different (P>0.05) from each other, but were better and significantly different (P<0.05) from treatments IV and V which had 1.3g and 1.2g; 14.5 and 12.4; and 0.7mm and 0.7mm respectively. 2 snails per cage was uneconomic. 3 to 4 snails per cage (75 to 100 snails per m2) was recommended as the optimal stocking density of fattening snails of A.m.s.


(Af. J. of Livestock Extension: 2003 2: 81-85)