Freshwater sponges (Porifera: Spongillidae) of Norway : distribution and ecology

• Published in: Hydrobiologia 1996, Vol.330 (1), p.1-30
• Main Authors: kland, Karen Anna, kland, Jan
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Freshwater; Fundamental and applied biological sciences. Psychology; Invertebrates; Porifera; Protozoa. Invertebrata; Spongillidae
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/bf00020819

Sponges were investigated during field studies of 609 lakes and other surface water bodies throughout Norway from 1960 to 1989. Material from other sources was also included in the study. Twelve environmental factors were registered. The presence or absence of Spongilla lacustris, Ephydatia muelleri and E. fluviatilis was studied statistically. Records of Eunapius fragilis and Anheteromeyenia ryderi were too few for statistical treatment. Spongilla lacustris occurred at 378 localities throughout Norway, 62 of which were north of the Arctic Circle, up to 71 degree 03' N (global maximum). Maximum elevation above sea level was 1397 m (maximum for northern Europe). The species preferred slightly acidic dystrophic lakes and rather low concentrations of calcium and magnesium, tending to avoid eutrophic lakes with rich macrovegetation and sites with high concentrations of calcium and magnesium. Ephydatia muelleri occurred at 98 localities throughout Norway. Ten sites were north of the Arctic Circle, up to 70 degree 28' N (global maximum). The highest altitude was 1030 m (maximum for northern Europe). E. muelleri preferred acidic dystrophic lakes but avoided the most acidic ones and those where the calcium concentration was very low. The species also favoured mesotrophic lakes with a medium to low calcium content and pH level. Ephydatia fluviatilis occurred at 16 localities in South Norway, up to 60 degree 53' N, and up to an altitude of 341 m. The species was generally associated with eutrophic lakes with lush macrovegetation. All records were from sites with high calcium concentrations (minimum 12.8 mg l super(-1)) and high pH (minimum 7.3). E. fluviatilis was absent from dystrophic, mesotrophic and oligotrophic lakes. Eunapius fragilis occurred in five eutrophic lowland lakes in southernmost Norway. Anheteromeyenia ryderi is known from four lowland lakes near the coast in southern and central Norway. S. lacustris and E. muelleri often occurred in the same lake, both species preferring acidic dystrophic environments. S. lacustris showed a particularly low degree of association with E. fluviatilis.