Materials and methods
Streptocephalus proboscideus is an inhabitant of the East African Sahel. Our initial material was dried mud from a temporary pool in the village of El Gedid in the Nile valley south of Khartoum, Sudan. Mass cultures were set up from cysts present in this mud, and were kept going for more than ten years. At a temperature of 25 C, this species maturates after less than two weeks, and may have a life span of up to nine months (Brendonck, 1993). At temperatures above 25 C, life
expectancy shortens strongly.