THE LIFE-CYCLE, ECOLOGY AND HOST SPECIFICITY OF THE FRESH-WATER LEECH ALBOGLOSSIPHONIA-POLYPOMPHOLYX (GLOSSIPHONIIDAE) IN EGYPT

Alboglossiphonia polypompholyx spends most of its life cycle endoparasitic in the mantle cavity of the snail Bulinus truncatus - possibly its only host. Adult A. polypompholyx leaves the snail about one month before the commencement of egg-laying. Hatching occurred after about 15 d and after brooding on the venter of the parent for 7-10 d, the young briefly become free-living before entering the mantle cavity of B. truncatus. Within the mantle cavity, A. polypompholyx feeds and grows for 16-20 weeks before leaving the snail as adults. In the field and in laboratory experiments, adult leeches left the snails in August/September and January with cocoons produced in October/November and February/March, respectively. Free-living adult leeches do not feed and die 1-2 months after the cessation of brooding.