Home News Archive - MPI for Ornithology Does parenting hamper the sex life of male black coucals? Publications of Filip de Ridder All genres Journal Article (1) Journal Article (1) 1998 Journal Article Beukeboom, L. W.; Seif, M.; Plowman, A. B.; de Ridder, F.; Michiels, N. K.: Phenotypic fitness effects of B chromosomes in the pseudogamous parthenogenetic planarian Polycelis nigra. Heredity 80 (5), pp. 594 - 603 (1998) MPG.PuRe DOI