1 The annelids 1

2 Survey of findings 1
2.1 Class Polychaeta 2
2.1.1 Order Errantia 2
2.1.2 Order Sedentaria 4
2.1.3 Order Archiannelia 10
2.2 Class Oligochaeta 11
2.2.1 Potamodrilidae 11
2.2.2 Aelosomatidae 12
2.2.3 Naididae 13
2.2.4 Tubificidae 13
2.2.5 Enchytraeidae 14
2.2.6 Lumbriculidae 16
2.2.7 Haplotaxidae 16
2.2.8 Lumbricidae 16
2.2.9 Branchiobdellidae 16
2.2.10 Megascolicidae 17
2.2.11 Eudrilidae 21
2.3 Class Hirudinea 22
2.3.1 Acanthobdellidae 22
2.3.2 Glossiphonidae 22
2.3.3 Piscicolidae 22
2.3.4 Hirudidae 22
2.3.5 HerpoLdellidae 22

3 Chromosomes and evolution 23
3.1 Evolution of chromosome numbers 23
3.2 Chromosomes and speciation 26
3.3 Karyology and phylogeny 29

4 Meiotic behaviour 30
4.1 Specialized bivalents 30
4.2 Asynaptic meiosis 33
4.3 Anaphasic disjunction 35


5 Parthenogenesis 38
5.1 Meiotic parthenogenesis 38
5.2 Amelotic parthenogenesis 41
5.3 General aspects of parthenogenesis 44

6 Sub-amphimictic reproduction 45

7 Pseudofertilization 49

8 Multiplication through transverse fission 51

9 Polyploidy 52

10 Biogeography and cytogenetics 60

11 Genetical studies on parthenogenetic annelids 61

References 73

Species Index 79