Description of Ceraclea nigronervosa (Retzius) larvae and pupae based on Norwegian specimens generally agree with those from Great Britain and North America, but differ from published Russian (U.S.S.R.) descriptions, probably due to the latter's being based on mixed species rearings. At least the last four of the five larval instars feed on freshwater sponge Spongilla lacustris (L.). Growth from the second instar on follows Dyar's rule with a 1.7 factor of increase. A population in the mountain stream Anfinnså, Dovre County, Norway (63°N and elevation 930-936 m) has a two cohort population with two years required for development. Greater numbers of Chironomidae, but not C. nigronervosa, occur in sponges containing the green algae Chlorella. Sponge-feeding Ceraclea may exhibit flexible life cycles.