Do earthworms (Dendrobaena octaedra) from differently polluted forests vary in life-history parameters?

Populations of the earthworm Dendrobaena octaedra originating from sites differently polluted with heavy metals were studied. Adult earthworms were collected in May-June 1995 in three mixed-pine forests (Pino-Quercetum): the most polluted one near Olkusz, the moderately polluted Niepo omice Forest (both Southern Poland) and the relatively unpolluted Kampinoska Forest (Central Poland). The mean live weights of adult animals collected in the field were 0.2372, 0.2259 and 0.1878 g (three Olkusz populations), 0.2876 and 0.2437 g (two populations from Niepo omice Forest), and 0.2375 g (Kampinoska Forest). There were statistically significant differences in body mass between populations, but not between sites. The pattern of body mass changes, during the first year, was similar for all populations. In the winter months, the disappearance of the clitellum was observed. Cocoon production was low during the first four months of culture (approximately 2 cocoons ind.–1 month–1) and high in Spring 1996 (19 cocoons ind.–1month–1). The mean fresh weights of cocoons collected in the field were 0.00396 g (Olkusz), 0.00429 and 0.00384 g (Niepo omice Forest), and 0.004 g (Kampinoska Forest). The mass of cocoons laid in the laboratory was lower. The populations studied differed in survival in laboratory cultures. The highest number of animals, surviving one year, was from the Olkusz populations.