EFFECT OF FEED TYPE ON GROWTH, SPERMATOZOA PRODUCTION AND GONADO-SOMATIC INDEX IN GIANT AFRICAN LAND SNAIL (Archachatina marginata)

Abstract

A study was conducted on the effect of feed type on growth, spermatozoa production and gonado-somatic index in giant African land snail (Archachatina marginata). Thirty snails (30) of weight range of 150 - 180g were used for this study. Ten snails (10) were assigned to each of the three feed types which included: Poultry layers mash (PLM), dried Pawpaw leaves (PL) and mixture of both Pawpaw leaves and Poultry layers mash (PLM+PL). Weight gain was monitored weekly. At the end of seven weeks, snails were dissected; visceral weight and ovo-testis were measured. Five (5) snails each per treatment were used for both histology and spermatozoa concentration estimation. Ovo-testis was processed for histology while little hermaphrodite duct was used for spermatozoa concentration. Results showed that feed type had significant (P<0.001) effect on sperm concentration. Snails fed on PL had higher sperm concentration, followed by those fed on PL+PLM while the least was found in PLM group. For live weight gain, those fed with PLM had the highest weight followed by those fed with PL+PLM while PL had least weight gain.  Results for gonado-somatic index showed that PL had the highest means while those fed on PLM and PL+PLM were not significantly different from each other. It was also found that snails fed with PL had high spermatogenic activity in the acini of snail ovo-testis while those fed with PLM+PL had medium activity and those fed with PLM had the least activity. The findings from this study suggest that pawpaw leaves have agents which promote spermatogenesis and can therefore be used as diet for breeding snails to enhance spermatogenesis.