In Memoriam: Professor Walter James Harman, PhD (1928-2002).- In Memoriam: Professor Walter James Harman, PhD (1928-2002).- Taxonomy, Anatomy, Morphology and Physiology.- Troglodrilus (Annelida, Oligochaeta, Tubificidae), a new genus from subterranean habitats in southwestern Europe.- Generation of bilateral symmetry in the ectoderm of the Tubifex embryo: involvement of cell-cell interactions.- Distribution pattern of ?-amino butyric acid immunoreactive neural structures in the central and peripheral nervous system of the tubificid worm, Limnodrilus hoffmeisteri.- Identification and pattern of primary sensory cells in the body wall epithelium of the tubificid worm, Limnodrilus hoffmeisteri.- Divergence of the F1-ATP synthase complex in the ice worm, Mesenchytraeus solifugus (Annelida, Clitellata, Enchytraeidae).- Life History.- From demographic strategies to mathematical models: trends in population dynamics studies of aquatic Oligochaeta.- Asexual reproduction and segmental regeneration, but not morphallaxis, are inhibited by boric acid in Lumbriculus variegatus (Annelida: Clitellata: Lumbriculidae).- Seasonal vertical migration and aestivation of Rhyacodrilus hiemalis (Tubificidae, Clitellata) in the sediment of Lake Biwa, Japan.- Survival and reproduction in Aeolosoma viride (Annelida, Aphanoneura).- Ecology and Toxicology.- Ecology and biology of marine oligochaeta - an inventory rather than another review.- Habitat preferences of aquatic Oligochaeta (Annelida) in the Rokytná River, Czech Republic - a small highland stream.- Beyond masses and blooms: the indicative value of oligochaetes.- Differential response of aquatic oligochaete species to increased nutrient availability - a comparative study between Estonian and Dutch raised bogs.- Toxicity of Santander Bay sediments to the euryhaline freshwater oligochaete Limnodrilus hoffmeisteri.- Oligochaete assemblages in the hyporheic zone and coarse surface sediments: their importance for understanding of ecological functioning of watercourses.- Surface and hyporheic oligochaete assemblages in a French suburban stream.- Sludge Studies.- Sludge reduction by predatory activity of aquatic oligochaetes in wastewater treatment plants: science or fiction? A review.- Sludge reduction with a novel combined worm-reactor.